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Analysis of Construction Worker Injury Information from a Workers' Compensation Database

Permanent Link: http://ufdc.ufl.edu/UFE0021403/00001

Material Information

Title: Analysis of Construction Worker Injury Information from a Workers' Compensation Database
Physical Description: 1 online resource (395 p.)
Language: english
Creator: Godfrey, Raymond
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2007

Subjects

Subjects / Keywords: construction, injury, workers
Design, Construction, and Planning -- Dissertations, Academic -- UF
Genre: Design, Construction, and Planning thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: In an effort to identify profiles of types and severity of injuries experienced by construction workers, my study sought to describe injuries sustained by construction workers at various occupational experience levels (laborers, apprentices, foremen), who performed in various occupational work areas (carpentry, masonry, electrical work) on construction sites. This study examined workers' compensation (WC) claims for the 46,056 construction workers. Claims information was provided by a large workers' compensation insurance provider. Injury frequencies and injury severity levels were calculated and compared across gender, age, job tenure (time between date of hire and date of injury), body region effected by injury, specific body part injured, nature of injury, cause of injury, and agent of injury. I used claims data reported to a large private insurance company according to National Council on Compensation Insurance job classifications. All injuries were examined as well as injuries sustained to each of six body regions: head; neck; trunk; upper extremities; lower extremities; and multiple body regions or body systems (MBRBS). Injured workers were generally young, averaging 37 years. Older workers tended to sustain more severe injuries; especially injuries to the neck, trunk, and lower extremities. Neck, MBRBS, and trunk injuries were the most severe injuries among the six body regions. Laborers sustained an inordinate amount of injuries to each of the body regions. They also sustained some of the most severe injuries to all six body regions. Journeymen sustained the most severe injuries to the upper extremities, as well as having the most severe MBRBS injuries. Injuries to the brain, cervical vertebrae, and heart were the most severe injuries. The eyes, thumb, and sacrum and/or coccyx, sustained the least severe injuries. Crushing to multiple body regions and to the head and myocardial infarctions were the most severe injuries. The occupational work area of the worker at the time of injury had no effect on the severity of the injury sustained.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Raymond Godfrey.
Thesis: Thesis (Ph.D.)--University of Florida, 2007.
Local: Adviser: Hinze, Jimmie W.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2017-12-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2007
System ID: UFE0021403:00001

Permanent Link: http://ufdc.ufl.edu/UFE0021403/00001

Material Information

Title: Analysis of Construction Worker Injury Information from a Workers' Compensation Database
Physical Description: 1 online resource (395 p.)
Language: english
Creator: Godfrey, Raymond
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2007

Subjects

Subjects / Keywords: construction, injury, workers
Design, Construction, and Planning -- Dissertations, Academic -- UF
Genre: Design, Construction, and Planning thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract: In an effort to identify profiles of types and severity of injuries experienced by construction workers, my study sought to describe injuries sustained by construction workers at various occupational experience levels (laborers, apprentices, foremen), who performed in various occupational work areas (carpentry, masonry, electrical work) on construction sites. This study examined workers' compensation (WC) claims for the 46,056 construction workers. Claims information was provided by a large workers' compensation insurance provider. Injury frequencies and injury severity levels were calculated and compared across gender, age, job tenure (time between date of hire and date of injury), body region effected by injury, specific body part injured, nature of injury, cause of injury, and agent of injury. I used claims data reported to a large private insurance company according to National Council on Compensation Insurance job classifications. All injuries were examined as well as injuries sustained to each of six body regions: head; neck; trunk; upper extremities; lower extremities; and multiple body regions or body systems (MBRBS). Injured workers were generally young, averaging 37 years. Older workers tended to sustain more severe injuries; especially injuries to the neck, trunk, and lower extremities. Neck, MBRBS, and trunk injuries were the most severe injuries among the six body regions. Laborers sustained an inordinate amount of injuries to each of the body regions. They also sustained some of the most severe injuries to all six body regions. Journeymen sustained the most severe injuries to the upper extremities, as well as having the most severe MBRBS injuries. Injuries to the brain, cervical vertebrae, and heart were the most severe injuries. The eyes, thumb, and sacrum and/or coccyx, sustained the least severe injuries. Crushing to multiple body regions and to the head and myocardial infarctions were the most severe injuries. The occupational work area of the worker at the time of injury had no effect on the severity of the injury sustained.
General Note: In the series University of Florida Digital Collections.
General Note: Includes vita.
Bibliography: Includes bibliographical references.
Source of Description: Description based on online resource; title from PDF title page.
Source of Description: This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility: by Raymond Godfrey.
Thesis: Thesis (Ph.D.)--University of Florida, 2007.
Local: Adviser: Hinze, Jimmie W.
Electronic Access: RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2017-12-31

Record Information

Source Institution: UFRGP
Rights Management: Applicable rights reserved.
Classification: lcc - LD1780 2007
System ID: UFE0021403:00001


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1 ANALYSIS OF CONSTRUCTION WORKER INJURY INFORMATION FROM A WORKERS COMPENSATION DATABASE By RAYMOND JOHN GODFREY A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2007

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2 2007 Raymond John Godfrey

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3 To all who provided the mentorship and support which made this milestone possible, with special recognition to Dr. Jimmie Hinze, Dr. Raymond Issa, Dr. David Suchman, and Ron Anderson. In memory of my father, William J. Godfrey

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4 ACKNOWLEDGMENTS I acknowledge the contributions of my mentor for Ph.D. study, Dr. Jimmie Hinze, for his guidance, patience, and encouragement during my st udy at the University of Florida. His efforts were essential for the completion of my study. He exemplified an academic and professional spirit which will inspire me in all of my future endeavors. This dissertation could not have been wr itten without the assi stance of Dr. Kevin Grosskopf, Dr. Robert Stroh, and Dr. William Prope rzio. I want to thank Professor Jo Hassell, who warmly guided and supported my growth an d development throughout the duration of my studies at the University of Florida. I thank all those friends and a ssociates who ensured that I never gave up on my dreams: Dr. Raymond Issa; Dr. Leon Wether ington; Dr. Charles Kibert; Dr. Caesar Abi; Dr. Ivan Mutis; Dr. David Suchman; Ron Anderson; the en tire Greenan family; Melisa Bilobran. Finally, I extend a very special thanks to Linda who entered my life at the right time; her unquestioning belief in my abilities inspired and motivated me to overcome those moments of self pity and self doubt.

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5 TABLE OF CONTENTS page ACKNOWLEDGMENTS...............................................................................................................4 LIST OF TABLES................................................................................................................. ........10 LIST OF FIGURES.......................................................................................................................16 ABSTRACT...................................................................................................................................26 CHAP TER 1 INTRODUCTION..................................................................................................................28 2 LITERATURE REVIEW.......................................................................................................31 USDOL-BLS Classifications of Construction Occupational Injury and Illness ....................35 Head Injuries...........................................................................................................................40 Injury Types and Mechanisms......................................................................................... 40 Neck Injuries...........................................................................................................................50 Throat & Trachea............................................................................................................ 51 Injury Types and Mechanisms......................................................................................... 52 Trunk Injuries.........................................................................................................................53 Injuries of the Thoracic Cavity........................................................................................ 53 Ribs and Sternum............................................................................................................55 Heart and Thoracic Blood Vessels.................................................................................. 56 Trachea, Esophagus and Diaphragm...............................................................................57 Liver................................................................................................................................58 Spleen..............................................................................................................................59 Kidneys............................................................................................................................60 Pancreas....................................................................................................................... ....61 Stomach...........................................................................................................................61 Small and Large Intestine................................................................................................ 62 Abdominal Wall.............................................................................................................. 63 Gall Bladder.....................................................................................................................63 Urinary Bladder...............................................................................................................64 Reproductive Organs (Male & Female).......................................................................... 65 Pelvis......................................................................................................................... ......65 Thoracic and Lumbar Spine (Thoracolumbar Spine)...................................................... 67 Upper Extremities.............................................................................................................. .....68 Types and Mechanisms of Injury....................................................................................69 Hand Injuries...................................................................................................................72 Lower Extremities..................................................................................................................72 Types and Mechanisms of Injury....................................................................................73 Ankle and Foot................................................................................................................75

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6 3 METHODOLOGY................................................................................................................. 78 Statistical Analysis........................................................................................................... .......86 4 RESULTS...............................................................................................................................91 Demographic Characteristics.................................................................................................. 93 Gender.............................................................................................................................93 Marital Status................................................................................................................. 103 Number of Dependents.................................................................................................. 105 Age................................................................................................................................105 Job Tenure.....................................................................................................................112 Occupational Work Area...................................................................................................... 114 Occupational Experience Level by General Occupational W ork Area................................ 116 Laborers.........................................................................................................................120 Apprentice.....................................................................................................................123 Journeyman.................................................................................................................... 125 Foreman.........................................................................................................................127 Supervisors....................................................................................................................128 Professional...................................................................................................................129 Administrators............................................................................................................... 130 Nature of Injury....................................................................................................................130 Cause of Injury................................................................................................................ .....142 Burn...............................................................................................................................145 Caught In or Between....................................................................................................147 Cut, Punctured, or Scraped............................................................................................148 Fall or Slip................................................................................................................... ..150 Motor Vehicle................................................................................................................ 153 Striking Against or Stepping On...................................................................................157 Struck By.......................................................................................................................159 Agent of injury......................................................................................................................161 General Agent of injury................................................................................................. 161 Building Exposure.........................................................................................................164 Chemical........................................................................................................................165 Lead...............................................................................................................................167 Machinery......................................................................................................................168 Manholes....................................................................................................................... 170 Material..........................................................................................................................170 Organism.......................................................................................................................173 Person............................................................................................................................175 Potholes.........................................................................................................................176 Power Lines or Poles.....................................................................................................177 Sharp Object Not Otherwise Classified (NOC)............................................................. 177 Change in Surface Texture............................................................................................ 177 Tool................................................................................................................................179 Vehicle...........................................................................................................................180 Weather Conditions....................................................................................................... 182

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7 Weighted Item............................................................................................................... 182 Date of Injury........................................................................................................................183 Year of Occurrence of Injury........................................................................................ 183 Month of Occurrence of Injury...................................................................................... 186 Day of the Week of Occurrence of Injury.....................................................................187 Injury Profiles by Body Region............................................................................................189 Body Region..................................................................................................................189 Body Region and Age...................................................................................................191 Experience Level........................................................................................................... 193 Laborers..................................................................................................................193 Helpers/Assistants.................................................................................................. 196 Apprentice..............................................................................................................199 Journeymen............................................................................................................ 201 Foreman..................................................................................................................203 Field Supervision.................................................................................................... 205 Professional............................................................................................................206 Administrative........................................................................................................208 Head Injuries.........................................................................................................................209 Body Part.......................................................................................................................209 Nature of Injury.............................................................................................................212 General Cause of Injury................................................................................................. 216 Occupational Work Area............................................................................................... 219 Occupational Experience Level..................................................................................... 221 Age................................................................................................................................225 Month of Occurrence of Injury...................................................................................... 227 Day of the Week of Occurrence of Injury.....................................................................228 Neck Injuries.........................................................................................................................231 Body Part.......................................................................................................................231 Nature of Injury.............................................................................................................233 General Cause of Injury................................................................................................. 236 Occupational Work Area............................................................................................... 239 Occupational Experience Level..................................................................................... 242 Age................................................................................................................................244 Job Tenure.....................................................................................................................246 Month of Occurrence of Injury...................................................................................... 248 Day of the Week of Occurrence of Injury.....................................................................251 Trunk.....................................................................................................................................252 Body Part.......................................................................................................................253 General Nature of Injury............................................................................................... 256 Nature of Injury.............................................................................................................257 General Cause of Injury................................................................................................. 261 Occupational Work Area............................................................................................... 265 Occupational Experience Level..................................................................................... 270 Age................................................................................................................................272 Job Tenure.....................................................................................................................276 Month of Occurrence of Injury...................................................................................... 278

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8 Day of the Week of Occurrence of Injury.....................................................................280 Upper Extremities.............................................................................................................. ...282 Body Part.......................................................................................................................282 Nature of Injury.............................................................................................................285 General Cause of Injury................................................................................................. 290 Occupational Work Area............................................................................................... 293 Occupational Experience Level..................................................................................... 297 Age................................................................................................................................299 Job Tenure.....................................................................................................................303 Month of Occurrence of Injury...................................................................................... 305 Day of the Week of Occurrence of Injury.....................................................................308 Lower Extremities................................................................................................................309 Body Part.......................................................................................................................310 Nature of Injury.............................................................................................................312 General Cause of Injury................................................................................................. 316 Occupational Work Area............................................................................................... 319 Occupational Experience Level..................................................................................... 323 Age................................................................................................................................325 Job Tenure.....................................................................................................................329 Month of Occurrence of Injury...................................................................................... 331 Day of the Week of Occurrence of Injury.....................................................................333 Multiple Body Regions or Body Systems............................................................................ 334 Body Part.......................................................................................................................335 Nature of Injury.............................................................................................................336 General Cause of Injury................................................................................................. 337 Occupational Experience Level..................................................................................... 341 Age................................................................................................................................343 Job Tenure.....................................................................................................................344 Month of Occurrence of Injury...................................................................................... 345 Day of the Week of Occurrence of Injury.....................................................................347 5 CONCLUSIONS.................................................................................................................. 349 6 RECOMMENDATIONS...................................................................................................... 360 Recommendations for Industry............................................................................................. 360 Recommendations for Insurance Carriers............................................................................ 363 Recommendations for Future Research................................................................................364 APPENDIX A DEFINITIONS FOR NATURE OF INJURY CODES........................................................ 366 B DEFINITIONS FOR PART OF BODY CODES .................................................................370 C DEFINITIONS OF CAUSE OF INJURY CODES.............................................................. 374 D AGENT OF INJURY CODES AND DEFINITIONS..........................................................380

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9 E STANDARD INDUSTRIAL CL ASSIFICATION (SIC) C ODES AND DEFINITIONS ... 384 LIST OF REFERENCES.............................................................................................................388 BIOGRAPHICAL SKETCH.......................................................................................................395

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10 LIST OF TABLES Table page 21 Body part region injured as a propor tion of all fatalitie s between 1992 and 2005 ............ 39 22 Body part region injured as a propor tion of all non-fatal ities between 1992 2005. .......... 39 31 Experience level of injured workers.................................................................................. 88 41 Gender of injured workers................................................................................................. 93 42 Comparison of injury frequencies between m ales and females by occupational experience level............................................................................................................... ..94 43 Injuries to males by nature of injury.................................................................................. 96 44 Injuries to females by nature of injury............................................................................... 97 45 Injuries to males by general cause of injury...................................................................... 98 46 Injuries to females by general cause of injury................................................................... 98 47 Comparison between males and females of injury severity m eans by body region........100 48 ANOVA, comparison, by gender, of injury severity m eans by body region................... 100 49 Injuries by marital status..................................................................................................104 410 Injuries by age..................................................................................................................106 411 Injuries by occupational work areas of injured workers.................................................. 117 412 Injuries by occupational e xperience level of injured worker ..........................................119 413 Injuries by occupational work area for laborers.............................................................. 120 4-14 Occupational work area of in jured helpers and assistants. .............................................. 122 415 Injuries to apprentices by occupational work area. .......................................................... 124 416 Injuries to journeymen by occupational work area.......................................................... 126 417 Injuries to foremen by occupational work area................................................................ 127 418 Injuries to supervisors by occupational work area. .......................................................... 128 419 Injury to professionals by occupational work area. ......................................................... 129

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11 420 Injuries to administrato rs by occupational work area. ..................................................... 130 421 Injuries by nature of injury..............................................................................................132 422 Injuries by general nature of injury.................................................................................. 134 423 Specific injuries by nature of injury................................................................................. 137 424 Occupational diseases or cumula tive injuries by nature of injury. .................................. 137 425 General cause of injury.................................................................................................. ..143 426 Cause of burn injuries................................................................................................... ...145 427 Causes of caught in or between injuries..........................................................................147 428 Causes of injury for cuts, punctures, and scrapes............................................................ 149 429 Causes of injuries from falls and slips............................................................................. 151 430 Causes of injuries involving a motor vehicle................................................................... 153 431 Causes of strain injuries................................................................................................ ...155 432 Causes of striking agai nst and stepping on injuries. ........................................................157 433 Causes of struck by injuries............................................................................................. 159 434 General agent of injury.................................................................................................. ..162 435 Agent of building exposure related injuries..................................................................... 165 436 Agent of chemical related injuries................................................................................... 166 437 Agent of furniture or furnishings related injuries............................................................ 167 438 Agent of lead related injuries........................................................................................... 168 439 Agent of machinery related injuries................................................................................. 169 440 Agent of injury for material related injuries.................................................................... 171 441 Agent of animal or insect related injuries........................................................................ 174 442 Agent of injuries related to a person................................................................................ 176 443 Agent of change in surface texture related injuries......................................................... 178 444 Agent of tool related injuries...........................................................................................179

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12 445 Agent of vehicle related injuries...................................................................................... 181 446 Agent of injuries related to weighted items..................................................................... 182 447 Year of injury...................................................................................................................184 448 Month of injury................................................................................................................186 449 Day of the week of injury................................................................................................188 450 Body region injured.........................................................................................................189 451 Ranking of injured body regions by injury distribution for occupational experience level am ong field based personnel...................................................................................194 452 Ranking of injured body regions by injury distribution for occupational experience level am ong administrative based personnel................................................................... 194 453 Injuries to laborers by body region..................................................................................195 454 Injuries to helpers and assistants by body region............................................................. 197 455 Injuries to body regions among apprentices.................................................................... 199 456 Injuries to journeymen by body region............................................................................ 201 457 Injuries to foremen by body region.................................................................................. 203 458 Injuries to field supervisors by body region. ................................................................... 205 459 Injuries to professionals by body region.......................................................................... 206 460 Injuries to field administ rative level workers by body region. ........................................ 208 461 Head injuries by body part............................................................................................... 210 462 Nature of head injuries.................................................................................................. ...213 462 Head injuries by general cause of injury.......................................................................... 217 463 Head injuries by occupational work area......................................................................... 220 464 Head injuries by occupational experience level............................................................... 223 465 Head injuries by month of occurrence............................................................................. 228 466 Head injuries by the day of the week of occurrence........................................................ 229 467 Neck injuries by body part injured...................................................................................231

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13 468 Neck injuries by nature of injury..................................................................................... 234 469 General cause of neck injuries.........................................................................................237 470 Neck injuries by occupational work area of injured workers.......................................... 240 471 Neck injuries by occupational experience level............................................................... 243 472 Neck injuries by age.........................................................................................................244 473 Injury frequency by job tenure of workers with neck injuries. ........................................247 474 Neck injuries by month of occurrence............................................................................. 249 475 Neck injuries by day of the week of occurrence.............................................................. 251 476 Trunk injuries by body part..............................................................................................253 477 Trunk injuries by general nature of injury.......................................................................256 478 Injury frequency by nature of trunk injury...................................................................... 259 479 General cause of trunk injury........................................................................................... 263 480 Occupational work area workers with trunk injuries. ...................................................... 267 481 Occupational experience level of workers with trunk injuries. ....................................... 270 482 Age of workers with trunk injuries.................................................................................. 273 483 Job tenure of workers with trunk injuries........................................................................ 277 484 Month of occurrence of trunk injuries. ............................................................................279 485 Day of the week of occurrence of trunk injuries.............................................................. 281 486 Injured body parts of th e upper extremities..................................................................... 283 487 Nature of injuries to the upper extremities...................................................................... 286 488 General cause of injury to the upper extremities............................................................. 291 489 Injury frequency by occupational work area of workers with upper extremityinjuries... 295 490 Occupational experience level of worker s with injuries to the upper extrem ities........... 297 491 Age of workers with upper extremity injuries................................................................. 300 492 Job tenure for workers with injuries to the upper extremities......................................... 304

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14 493 Month of occurrence of upper extremity injuries............................................................306 494 Day of the week of occurre nce of upper extrem ity injuries............................................. 309 495 Injured body parts of th e lower extremities..................................................................... 310 496 Nature of injury to th e lower extremities.........................................................................313 497 General cause of lower extremity injuries....................................................................... 317 498 Occupational work areas of workers with lower extremity injuries................................ 321 499 Occupational experience level of wo rkers with lower extrem ity injuries.......................324 4100 Age of workers with in ju ries to lower extremities........................................................... 326 4101 Job tenure of workers with lower extremity injuries....................................................... 330 4102 Month of occurrence of lower extremity injuries. ...........................................................332 4103 Day of the week of occurrenc e of lower extrem ity injuries............................................. 333 4104 Injured body parts of MBRBS injuries............................................................................ 335 4106 General cause of multiple body region or body systems (MBRBS) injuries................... 338 4107 Occupational work areas of workers with multiple body regions or body systems (MBRBS) injuries. ...........................................................................................................340 4108 Occupational experience level of worker s with injuries to m ultiple body regions and body systems....................................................................................................................342 4109 Age of workers with MBRBS injuries............................................................................. 343 4110 Job tenure of workers with MBRBS injuries................................................................... 345 4111 Month of occurrence of MBRBS injuries........................................................................ 346 4112 Day of the week of o ccurrence of multip le body regions or body systems injuries........ 347 51 Most and least severely injured wo rkers by occu pational experience level from injuries to the general body regions................................................................................. 351 52 Most and least severe injuries by body region. ................................................................352 53 Most and least severe injured body part s per body region (also shows m ean age)......... 353 54 Most and least severe nature of injures by body part.......................................................355

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15 55 Most and least severe occupa tional work areas by body region. ..................................... 357 A1 Specific Injuries...............................................................................................................366 A2 Occupational diseases or cumulative injuries.................................................................. 368 A3 Multiple Injuries......................................................................................................... ......369 B1 Head.................................................................................................................................370 B2 Neck.................................................................................................................................370 B3 Upper extremities.............................................................................................................371 B4 Trunk................................................................................................................................371 B5 Lower extremities......................................................................................................... ...372 B6 Multiple body parts....................................................................................................... ...373 C1 Burn or scald....................................................................................................................374 C2 Caught in or between.......................................................................................................375 C3 Cut, puncture, scrape........................................................................................................375 C4 Fall or slip.............................................................................................................. ..........375 C5 Motor vehicle...................................................................................................................376 C6. Strain................................................................................................................... .............376 C7 Striking against or stepping on ........................................................................................ 377 C8 Struck by..........................................................................................................................378 C9 Rubbed or abraded by...................................................................................................... 378 C10 Miscellaneous causes.......................................................................................................379 D1 Agent of injury.................................................................................................................380 D2 General agent of injury................................................................................................... .382 E1 Standard industrial classification (SIC) codes. ................................................................ 384

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16 LIST OF FIGURES Figure page 21 Yearly construction fatalities as a percent of all occupational fatalities. ........................... 32 22 Frequency of occupation fata lities for all industries 1992-2005. ...................................... 32 23 Frequency of occupation fatalitie s for the construction industry, 1992-2005.. .................33 24 Percentage of fatalities be tween 199 2 and 2005 (All Industries)......................................38 25 Percentage of fatalities between 199 2 and 2005 (Construction Industry)......................... 38 26 Position of the cranium and bones of the cranium .............. ............................................ 41 27 Structure and lobes of the brain. ....................................................................................... 42 28 Structure of the ear ..................................................................................................... .......44 29 Structure of the eye...................................................................................................... ......45 210 Structure of the nasal cavity. .......................................................................................... ...47 211 Front and side view of th e structure of the m outh. ........................................................... 49 212 Vertebrae of the neck and st ructure of the verteb ral column ............................................52 2-13 Side view of thorax (rib s, lungs and diaphragm ). .............................................................54 214 Detail of the sternum and ribs 1 to 12 ............................................................................... 55 2-15 Position of the heart and structure of the heart with cross sectional view ................... .... 56 216 The larynx, pulmonary lobes and bron chi of the lungs, and diaphragm .......................... 58 217 The position in the human body, and th e exterior structure of the liver........... ................ 59 218 Positions of the spleen kidneys and pancreas in the hum an body. ................................... 60 219 Positions of the organs of the lower digestive system in the human body. ...................... 62 220 Position of the gall bladder. ........................................................................................... ...64 221 The position of the urinary bladder. ..................................................................................64 222 The bones of the pelvis. ................................................................................................ ....66

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17 223 Side view of the vertebral column. Each vertebra is num bered according to the part of the spine it is in, e.g., the lumb ar vertebrae are L1 through L5. ................................... 68 224 Bones of the upper extremities.......................................................................................... 69 225 Bones of the lower extremities.......................................................................................... 73 31 Protocol for statistical multiple comparison of means....................................................... 87 32 Comparison of injury severity means by occupational experience levels. ........................ 89 33 Differences of injury severity means by occupational experience levels.......................... 89 41 Comparison of injury severity means by body region for injuries to m ale workers........ 101 42 Difference of injury severity means between body regions for injuries to male workers. ............................................................................................................................102 43 Comparison injury severity means by body region for female workers.......................... 103 44 Difference of injury severity means between body regions for fe male workers............. 103 45 Comparison of injury seve rity m eans by marital status................................................... 104 46 Comparison of injury severity means by number of dependents..................................... 106 47 Comparison of mean ages by occupational experience level. ......................................... 107 48 Differences of mean ages between general occupational experience levels. ...................108 49 Comparison of injury severity means by age for non-new hires..................................... 109 410 Differences of injury severity means between age groups of non-new hires.................. 110 411 Comparison of injury severity means by age of new hires.............................................. 111 4-12 Differences of injury severity means between ages of new hires.................................... 111 413 Differences of injury severity mean between new hire and non-new hire w orkers by age....................................................................................................................................112 414 Daily injury rate by job tenure......................................................................................... 113 415 Comparison of injury severity means by job tenure........................................................ 114 416 Comparison of injury severity means by job tenure........................................................ 115 417 Comparison of injury severity m eans by occupational work area................................... 118

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18 418 Comparison of injury severity m eans by occupational experience level......................... 119 419 Differences of injury severity means between occupational experience levels. .............. 120 420 Comparison of injury severity mean s by occupational work area for laborers. .............. 121 421 Comparison of injury severity means by occupational work area of injured helpers or assistants. .................................................................................................................... .....123 422 Comparison of injury severity mean s by occupational work areas for injured apprentices. ................................................................................................................... ...125 423 Comparison of injury severity mean s by occupational work areas for injured journeym en..................................................................................................................... .126 424 Comparison of injury severity mean s by occupational work areas for injured fore men............................................................................................................................128 425 Comparison of injury severity means by occupational work area of injured supervisors. ......................................................................................................................129 426 Comparison of injury severity mean s by occupational work areas of injured professionals. ...................................................................................................................130 427 Comparison of injury severity mean s by occupational work areas of injured adm inistrators................................................................................................................. ..131 428 Comparison of injury severity m eans by top ten nature of injury...................................133 429 Injury severity means for the bottom ten nature of injury............................................... 133 430 Comparison of injury severity m eans by general nature of injury................................... 135 431 Comparison of injury severity m eans by general nature of injury................................... 135 432 Comparison of injury severity means by nature of injury for specific injuries. .............. 138 433 Differences of injury severity mean s between nature of specif ic injuries....................... 140 434 Comparison of injury severity means by nature of occupational disease or cum ulative injury......................................................................................................................... .......141 435 Comparison of injury severity mean s by nature of occupational diseases and cum ulative injuries........................................................................................................... 142 436 Comparison of injury severity m eans by general cause of injury.................................... 144 437 Comparison of injury severity m eans by general cause of injury.................................... 144

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19 438 Comparison of injury severity means by cause of burn injury........................................ 146 439 Differences of injury severity m eans between causes of burn injuries............................ 146 440 Comparison of injury severity means by cause of caught in or between injuries............ 148 441 Differences of injury severity mean s between causes of caught in or between injuries..............................................................................................................................148 442 Comparison of injury severity means by causes of cuts, punctures, and scrapes. ........... 150 443 Differences of injury severity means be tween causes of cuts, punc tures, and scrapes. .. 150 4-44 Comparison of injury severity means by causes of injuries from falls and slips............. 152 445 Differences of injury severity means be tween causes of injury from falls and slips....... 152 446 Comparison of injury severity means by causes of injuries involving a m otor vehicle.. 154 447 Comparison of injury severity m eans by causes of st rain injuries................................... 156 448 Differences of injury severity m eans between causes of strain injuries. ......................... 156 449 Comparison of injury severity means by causes of injuries from striking against or stepping on.................................................................................................................... ...158 450 Differences of injury severity means be tween causes of striking against or stepping on injuries.........................................................................................................................158 451 Comparison of injury severity m eans by causes of struck by injuries. ............................ 160 452 Differences of injury severity mean s between causes of struck by injuries. ................... 161 453 Comparison of injury severity m eans by general agents of injury.................................. 163 454 Differences of injury severity means between general agents of injury.......................... 164 455 Comparison of injury severity means by agent of che mical related injuries................... 166 456 Comparison of injury severity means by agent o f furniture or furnishings related injuries..............................................................................................................................167 457 Comparison of injury severity mean s by agent of lead related injuries. .......................... 168 458 Comparison of injury severity means by agent of m achinery related injuries................ 170 459 Comparison injury severity means by agent of m aterial related injuries......................... 172 460 Differences of injury severity means be tween agents of m ateri al related injuries.......... 173

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20 461 Comparison of injury severity means by agent of organism related injuries.................. 175 462 Differences of severity means between agents of organism related injuries...................175 463 Comparison of injury severity mean s by agent of person related injuries. ...................... 176 464 Comparison of injury severity means by agent o f change in surface texture related injuries..............................................................................................................................179 465 Comparison of injury severity mean s by agent of tool related injuries. .......................... 180 466 Difference of injury severity means be tween agents of tool related injuries. ..................180 467 Comparison injury severity means by agent of vehicle related injuries. ......................... 181 468 Comparison of injury severity mean by agent of weighted item related injuries. ........... 183 469 Comparison of injury severity means by year of occurrence.......................................... 185 470 Differences of injury severity means between years of occurrence................................ 185 471 Comparison of injury severity m eans by month of injury occurrence.............................187 472 Comparison of injury severity means by day of the week of injury occurrence. ............ 188 473 Differences of injury severity means between day s of the week of injury occurrence... 189 474 Comparison of injury severity means by body region..................................................... 190 475 Differences of injury severity means between body regions........................................... 191 476 Mean age by injured body region.................................................................................... 192 477 Difference of mean ages between injured body regions.................................................. 192 478 Comparison of injury severity means by body region for laborers................................. 196 479 Differences of mean ages between body regions for laborers. ........................................ 196 480 Comparison of injury severity m eans by body region injuries to helpers and assistants. .................................................................................................................... .....198 481 Differences of injury severity means between body regions injured am ong helpers and assistants....................................................................................................................198 482 Comparison of injury severity mean s by body regions injured am ong apprentices........ 200 483 Differences of injury severity means between body regions among apprentices............ 200

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21 484 Comparison of injury severity m eans by body region among journeymen.)................... 202 485 Differences of injury severity m eans between body regions among journeym en........... 202 486 Comparison of injury severi ty m eans by body region among foremen........................... 204 487 Differences of injury severity mean s between body region injuries to foremen. ............ 204 488 Comparison of injury severity m eans by body region am ong field supervisors.............. 206 489 Comparison of injury severity m eans by body region among professionals................... 207 490 Differences of injury severity mean s between body regions among professionals. ........ 208 491 Comparison of injury severity mean s by body region am ong administrative workers... 209 492 Comparison of injury severity means by body part of head............................................ 211 493 Differences of injury severity means between injured body parts of the head................ 212 494 Comparison of injury severity mean s by nature of injury to the head. ............................ 215 495 Differences of injury severi ty by nature of head injury. .................................................. 216 496 Comparison of injury severity m eans by general cause of head injury. .......................... 218 497 Differences of injury severity means between the general causes of head injury. .......... 219 498 Comparison of injury severity means by occupational work area of workers with a head injury. ......................................................................................................................222 499 Comparison of injury severity means by occupational experience level of workers with head injuries. ............................................................................................................224 4100 Differences of injury severity between occupational experience levels of workers with head injuries. ............................................................................................................224 4101 Comparison of mean ages by body part of the head injured............................................ 225 4102 Differences of mean ages by body parts of the head injured. ......................................... 226 4103 Comparison of injury severity means by age of workers with head injuries. .................. 227 4104 Comparison of injury severity means by m onth of occurrence of head injuries............. 229 4105 Comparison of injury severity means by the day of the week of occurrence of head injuries..............................................................................................................................230 4106 Comparison of injury severity means by body part of the neck injured.......................... 232

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22 4107 Differences of injury severity means between inured body parts of the neck................. 233 4108 Comparison of injury severity m eans by nature of neck injury. ..................................... 235 4109 Differences of injury severity means by nature of neck injury........................................ 236 4110 Comparison of injury severity mean s by general cause of neck injuries. ........................ 238 4111 Differences of injury severity means between general causes of neck injury. ................ 238 4112 Comparison of injury severity means by occupational work area of workers with neck injuries. ....................................................................................................................241 4113 Comparison of injury severity means by occupational experience levels of workers with neck injuries. ............................................................................................................243 4114 Comparison of injury severity means by age of workers with neck injuries. ................ 245 4115 Differences between injury severity m eans by age of workers with neck injuries. ......... 245 4116 Comparison of mean ages by body part of neck injuries................................................. 246 4117 Comparison of injury severity means by j ob tenure of workers with neck injuries. ....... 247 4118 Comparison of injury severity means by m onth of occurrence of neck injuries. ........... 250 4119 Differences between injury severity mean s by month of occurrence of neck injuries. ... 250 4120 Comparison of injury severity means by day of the week of occurrence of neck injury. ........................................................................................................................ .......252 4121 Comparison of injury severity m eans by injured body parts of the trunk....................... 255 4122 Differences of injury severity means by injured body parts of the trunk........................255 4123 Comparison of injury severity mean s by general nature of trunk injuries. ...................... 257 4124 Differences of injury severity means by general nature of trunk injuries........................ 257 4125 Comparison of injury severity m eans by nature of trunk injuries................................... 260 4126 Differences of injury severity m eans between nature of trunk injuries. .......................... 262 4127 Comparison of injury severity mean s by general cause of trunk injuries. ....................... 264 4128 Differences of injury severity means by general causes of trunk injuries. ...................... 265 4129 Comparison of injury severity mean by occupational work area for workers with trunk injuries. ...................................................................................................................268

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23 4130 Differences of injury severity means between occupational work area of workers with trunk injuries. ........................................................................................................... 269 4134 Comparison of injury severity means by occupational experience level of workers with trunk injuries. ........................................................................................................... 271 4132 Differences of injury severity means between occupational experience areas of workers with trunk injuries. ............................................................................................. 272 4133 Comparison of injury severity mean s by age of workers with trunk injuries. ................. 274 4134 Differences between injury sever ity m eans by age group for trunk injuries................... 274 4135 Comparison of mean ages by injured body part of the trunk. .......................................... 275 4136 Differences of mean ages be tween inured body parts of the trunk. ................................. 276 4137 Comparison of injury severity means by j ob tenure of workers with trunk injuries. ...... 278 4138 Comparison of injury severity means by m onth of occurrence of trunk injuries............ 280 4139 Comparison of injury severity means by day of the week of occurrence of trunk injuries..............................................................................................................................282 4140 Comparison of injury severity means by injured body parts o f the upper extremities.... 284 4141 Differences of injury severity means by injured b ody parts of the upper extremities..... 285 4142 Comparison of injury severity means by nature of injury to the upper ex tremities........ 288 4143 Difference of injury severity means by nature of injury to the upper extrem ities........... 289 4144 Comparison of injury severity means by general cause of upper extrem ity injury......... 292 4145 Differences of injury severity means by the general causes of injury to the upper extrem ities........................................................................................................................293 4146 Comparison of injury severity means by occupational work area of workers with upper extrem ity injuries................................................................................................... 296 4147 Comparison of injury severity means by occupational experience level of workers with upper extrem ity injuries........................................................................................... 298 4148 Differences of injury severity mean by occupational experience levels for workers with upper extrem ity injuries........................................................................................... 299 4149 Comparison of injury severity mean s by age of workers with upper extrem ity injuries..............................................................................................................................301

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24 4150 Differences of injury severity means by ages of workers with injuries to the upper extrem ities........................................................................................................................301 4151 Comparison of mean ages by upper extrem ity body part injured.................................... 302 4152 Differences of mean ages by injured upper extremity body part..................................... 303 4153 Comparison of injury severity means by job tenure of workers with upper extrem ity injuries..............................................................................................................................305 4154 Comparison of injury severity means by m onth of occurrence of injuries to the upper extremities........................................................................................................................307 4155 Comparison of injury severity means by day of the week of occurrence of upper extrem ity injuries............................................................................................................. 309 4156 Comparison of injury severity means by injured body parts o f the lower extremities.... 311 4157 Differences of injury severity means between injured body parts of the lower extrem ities........................................................................................................................312 4158 Comparison of injury severity means by nature of lower extrem ity injuries.................. 315 4159 Differences of injury severity means by nature of injury to the lower extrem ities......... 316 4160 Comparison of injury severity means by general cause of lower extrem ity injuries....... 319 4161 Difference of injury severity means by general causes of lower extrem ity injuries........ 319 4162 Comparison of injury severity means by occupational work areas of workers with lower extrem ity injuries................................................................................................... 322 4163 Comparison of injury severity means by occupational experience level of workers with lower extrem ity injuries........................................................................................... 325 4164 Differences of injury severity means by occupational experience levels of workers with lower extrem ity injuries........................................................................................... 325 4165 Comparisons of injury severity means by age of workers with lower extremity injuries..............................................................................................................................327 4166 Differences of injury severity means by age of workers with lower extremity injuries. 327 4167 Comparison of mean ages by injured body parts of lower extrem ity injuries................. 328 4168 Differences of mean ages by inju red body parts o f the lower extremities....................... 329 4169 Comparison of injury severity means by job tenure of workers with lower extrem ity injuries..............................................................................................................................331

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25 4170 Comparison of injury severity means by m onth of occurrence of lower extremity injuries..............................................................................................................................333 4171 Comparison of injury severity means by day of the week of occurrence of lower extrem ity injuries............................................................................................................. 334 4167 Comparison of injury severity mean s by injured body parts of MBRBS injuries. ..........335

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26 Abstract of Dissertation Pres ented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy ANALYSIS OF CONSTRUCTION WORKER INJURY INFORMATION FROM A WORKERS COMPENSTATION DATABASE By Raymond John Godfrey December 2007 Chair: Jimmie Hinze Major: Design, Construction and Planning In an effort to identify profiles of type s and severity of in juries experienced by construction workers, my study sought to describe injuries sustained by construction workers at various occupational experience levels (e.g., laborers, apprentices, foremen), who performed in various occupational work areas (e.g., carpentry, masonry, electrical work) on construction sites. This study examined workers' compensation (W C) claims for the 46,056 construction workers. Claims information was provided by a large work ers' compensation insurance provider. Injury frequencies and injury severity levels were ca lculated and compared across gender, age, job tenure (i.e., time between date of hire and date of injury), body re gion effected by injury, specific body part injured, nature of injur y, cause of injury, and agent of injury. I used claims data reported to a large private insurance compa ny according to National Council on Compensation Insurance job classifications. All injuries were exam ined as well as injuries sustained to each of six body regions: head; neck; trunk; upper extr emities; lower extremities; and multiple body regions or body systems (MBRBS). Injured workers were generally young, averaging 37 years. Older workers tended to sustain mo re severe injuries; especially injuries to the neck, trunk, and lower extremities. Neck, MBRBS, and trunk injuries were the most severe injuries among the six

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27 body regions. Laborers sustained an inordinate amount of injuries to each of the body regions. They also sustained some of the most severe injuries to all six body regions. Journeymen sustained the most severe injuries to the upper extremities, as well as having the most severe MBRBS injuries. Injuries to the brain, cervical vertebrae, and heart were the most severe injuries. The eyes, thumb, and sacrum and/or coccyx, sustained the le ast severe injuries. Crushing to multiple body regions and to the head and myocardial infarctions were the most severe injuries. The occu pational work area of the worker at the time of injury had no effect on the severity of the injury sustained.

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28 CHAPTER 1 INTRODUCTION The construction industry is dive rse. According to the Uinited States Department of Labor Beuraue of Labor Statistics (USD OL-BLS), within the United States, construction employment is 30 percent of total employment in the goods -producing sectors (including manufacturing, natural resources and mining), wh ile construction establishments account for 62 percent of all goods-producing establishments (U SDOL BLS, 2006a). In the U.S. economy as a whole (goodsproducing and service-providing sect ors), construction employs about 5.4 percent of all workers and accounts for 9.8 percent of all establishments. Current employment statistics estimates s how the total average annual construction employment rising from 5,536,000 in 1996 to an all-time high of 7,277,000 in 2005, surpassing the previous high achieved in 2004 (USDOL-BLS 2006a). Numerous construction enterprises deliver a diversity of services from residen tial building renovation a nd development to major infrastructure projects. In the area of occupati onal safety, the constructio n industry continues to be one of the most dangerous occupational setti ngs for workers. In 2005, there were 1,186 fatal occupational injuries in construction and 414,900 nonfatal injuries and illnesses (USDOL-BLS, 2006b). The nonfatal injuries and i llnesses incidence rate was 6.3 per 100 full-time workers in construction compared to 4.6 per 100 full-time workers in all private industry (USDOL-BLS, 2006c). Workers on construction sites face multiple and varied threats to safety. The variability of risk of injury within the construction industry has also been demonstrated. For instance, previous analyses have shown that risk of injury is hi gher for workers in certain construction domains, such as building construction and site development, than in others, such as roadway construction (Lowery et al., 1998). Risk has also been found to be higher for special trade contractors than for

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29 other types of contractors (Glazn er et al., 1998). Other analyses have shown differences in the proportionate distribution of injuri es among trades (Helander, 1991; Hunting et al., in press] and by phase and type of construc tion (OSHA, 1992b; Construction Sa fety Association of Ontario, 1995). While such studies establish the variati on in risk of injury among trades, types of contractors and broad constr uction domains, they are limited in th eir ability to detect the specific types of work activities associated with injur y, and information necessary for allocating safety resources and preventing injury. Even studies focusing on a single trade may not reflect this variation insofar as members of that trade are involved in a variety of work activities. Over the years, especially the past three decades, considerable resources have been committed to reducing the number of construction wo rker fatalities, non-fatal injuries of varying degrees of severity, and illnesses that result from exposure to various substances encountered in the construction industry. Despite these efforts, the construction industry remains one of the most dangerous industries for workers (Leigh and Mi ller, 1997). Each year nearly 1200 construction workers die on construction projects and nearly half a million workers are injured. The problem is serious and deserves further research to continue to make improvements. Workers' compensation (WC) has often been u tilized as a source of workers data for occupations at high risk of injury and illness an d analyzed for those occpations demographics and industrial characteristics. Workers compensation data have been used previously to generate worker fatality and injury profiles for the c onstruction industry (Hinze, J., 2006; Horowitz, B., and McCall, B., 2005; Lombardi, D. A., et. al., 2005; Dement, J., Lipscomb, H., et. al., 2003; Enders, L. and Walker, W., 2003; Dement, J.M., and Lipscomb, H., 1999; Lipscomb, H. J. et. al., 1997 Cattledge, G.H. et. al., 1996). Because this t ype of data often report on both fatal and nonfatal accidents providing information on employee demographics, injury type, injured body

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30 part, severity, agent of loss, the injury costs, job tenure, disabili ty length, and regular occupation of the worker. The data allows for the assessm ent of multiple risk factors associated with construction work among large employee populations The data also record information about the day and month of injury which can further be examined for possible associations with the number of injuries sustained by the construction workers (Coleman, 1984). Through a detailed review and analysis of workers compensation data from a private insurance provider, my study study will contribute to the literature on workplace injuries in the construction industry. Specifically, relationships will be examined between factors such as specific injury types, affected body part, specif ic types of work (e.g., iron and steel erection, glass installation, etc.) and speci fic occupational role (e.g., boilerm aker, electrician, carpenter, laborer, etc.) thus permitting the development of safe ty strategies specific to these variables. The types of work associated with high injury rates or particularly severe injuries on construction sites will also be identified, thus allowing owners, contractors, and safety professionals to direct their safety efforts toward the specific activitie s presenting particularly high risk. Because these claims data also record information on the day and month of injury, time of occurrence factors will also be examined for possible associations with work-related injuries experienced by workers in the construction industry.

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31 CHAPTER 2 LITERATURE REVIEW Construction is one of the largest in dustries in the United States, employing approximately 7.3 million individuals. In the U.S. economy the construction industry employs about 5% to 6% of all workers. It is well known that cons truction is one of the most dangerous industries. Construction wo rk frequently involves cluttered work environments, extreme temperatures, conf ided work spaces, elevated work spaces, operation of power tools and heavy machinery, use of various sharp objects, overhead tasks, and work demanding frequent be nding, twisting and strenuous handling of equipment and materials of si gnificant weight. The work environment in construction is subject to constant flux and imposes the need for workers to be attentive to potential new hazards. Construction is also characterized by a highly transient worker population which frequently change employers and work sites. According to the United States Bureau of Labor Statistics (USDOL-BLS, 2006b) the private construction industr y accounted for 1,186 fatal work injuries, the most of any industry sector and accounted for nearly one out of every five fatal work injuries recorded in 2005. Reasons for the higher worker fatality rates in the constr uction industry include contact with high-voltage indus trial wiring and machinery (O re and Casini, 1996; Pratt, Kisner and Moore, 1997; Robinson, C.F ., Peterson, M., and Palu, 1999), exposure to toxic agents (Dorevich, Fors t, Conroy and Levy, 2002), working at elevations which increase the risk of serious falls, involvement in work related activities that increase the risk of fatal encounters with heavy equipmen t (Pratt et. al., 1997; Cattledge, Hendricks and Stancvich, 1996), and materials, and mo tor vehicles (Ore and Fosbroke, 1997).

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32 In 2005 about 22 percent of a ll fatal on-the-job injuries occurred in construction, over three times its 6% share of the total employment (USDOL-BLS, 2006b). From 1992 through 2005 and there was an increase of fata lities within the US construction industry as a percent of all occupationa l fatalities (see Figure 21). The trend of a reduced frequency of occ upational fatalities among all industries between 1992 and 2005 suggests a slightly reversed trend within the US construction industry; however, this does not show the increase in construction employment that occurred during this period (see Figure 22 and Figure 23). 15.50% 15.34% 16.24% 17.50% 17.66% 18.21% 19.93% 20.28% 19.98% 21.39% 20.83% 21.00% 22.17% 21.71% 0.00% 5.00% 10.00% 15.00% 20.00% 25.00% 19921993199419951996199719981999200020012002200320042005 Year Figure 21.Yearly construction fatalities as a percent of all occupational fatalities (USDOL-BLS, 2006b). 6212 6331 6632 6275 6202 6238 60556054 59205915 5534 5575 5764 5702 4800 5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 19921993199419951996199719981999200020012002200320042005 Year Figure 22. Frequency of occupation fatali ties for all industries 1992-2005. (USDOL-LS, 2006b).

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33 963 971 1077 1098 1095 1136 1207 1228 1183 1265 1153 1171 1278 1238 0 200 400 600 800 1000 1200 1400 19921993199419951996199719981999200020012002200320042005 Year Figure 23. Frequency of occupation fata lities for the construction industry, 1992-2005. (USDOL-BLS, 2006b). Every day on the job, construction workers face the probability of a fatal, workrelated injury that is over 2.5 times higher than that experi enced by other US workers in private industry (BLS, 1992 2005). The construction industry is also identified as having high rates of reported nonfatal occupational injuries (Gillen et. al., 1997), including eye inju ries (Lombardi et. al., 2005; Welsh, et. al., 2001), hearing damage (Hessel, 2000), musculoskeletal disorders (Goldsheyder, 2004; Schneider, 2001; Lipscomb et. al, 1997; Holmstrom, et. al.., 1995) burns (Islam, et al., 2000; Zwerling et. al., 1996), and psychosocia l disorders (Savitz, Boyle and Holmgreen, 1994). In 2005, there were 4 lost workday cases per 100 full time equivalent construction workers compared to a rate of 3/100 full time equivalent work ers in all private industry; the rate in construction exceeded all ot her sectors (USDOL-BLS, 2006c). Non-fatal injury rates in all industries and injury rate s in construction, in particular, have been declining. Within this overall decline, there ha s been a decline in injuries resulting in time away from work.

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34 Demgraphic factors such as gender and age have been associated with increased injury risk for construction workers. Resear ch suggests that female construction workers have a higher overall rate of fatalities than male workers, although males have higher fatality rates for some specific tasks or cau ses such as electrocuti ons (Ore and Casini, 1996; Kines, P., 2002; Ore, T., 1998; Ore, T. and Stout, N.A., 1997). Welch, Goldenhar and Hunting (2000) have shown that women working in construction have a different pattern of fatal injuries than male work ers. They have also shown that female construction workers have different patterns of various nonfatal inju ries when compared with males working in construction. Age was found to be correlated with the causes of occupational injuries in the construction industry. Several studies have shown that young workers (< 30 years) are involved in more work-related injuries, especially those caused by hand tools, (Chau, N. et. al., 2003; Chau, N. et. al., 2002) due to lack of experience. Research has shown that health problems, especially related to muscul oskeletal injuries, increase with advancing age (de Zwart and Frings-Dresen, 1999). Age (> 30 years) has been positively correlated with number of hospitalizations and durati on of sick leave (Chau, N. et. al., 2004). Brenner and Ahern (2000) have shown that older construction workers find it more difficult to recover after an accident than younger workers. In a study of teens working in the homebuilding industry in North Carolina, Lipscomb and Li (2001) found that teens had higher rates of eye and foot injuries but lo wer rates of lower back injuries than older workers. Teen workers revealed a higher rate of injury types attributable to cuts and scratches but fewer injuries resulting from sprains and strains than older workers.

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35 USDOL-BLS Classifications of Constructi on Occupational Injury and Illness The Occupational Injury and Illness Classification Syst em (OIICS) was developed by the United States Department of Labors (USDOL) Bureau of Labor Statistics (BLS) to establish a set of procedures for selecting and recording facts related to an occupational injury, illness, or fatality (USDOL-BLS, 1992). OIICS is designed to be as compatible as possible with the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9 CM), which is wide ly used in the medical community. The Occupational Injury and Il lness Classification System contains a code structure for Part of Body Affected. This is the part of bod y directly affected by the identified nature of injury or illness. The Part of B ody Affected code structur e is arranged in order from the top of the body (Head) to the botto m of the body (Lower Extremities). The Part of Body Affected divisions are arranged as follows: Head Neck (including throat) Trunk Upper extremities Lower extremities Body systems Multiple body parts Other body parts Nonclassifiable. For this report classifications for nature of injury type, cause of injury, industry, and employment activity mimics the system established by the National Council of Compensation Insurance (NCCI). The majority of U.S. jurisdictions use the NCCI as their workers compensation rating burea u. NCCI sets rules regarding how an occupational injury or illness becomes clas sified along several dimensions (nature of injury, cause of injury, type of business enterprise, type of employment activity). This

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36 classification system utilizes around 600 classi fication codes. These codes and the rules of applying these codes are detailed in The Scopes of Basic Manual Classifications (NCCI, 2007). The NCCI cause code is used to describe what caused an in jury or occupational disease. This code is divided into the fo llowing nine categories. The ninth category All Other Claims, NOC (Not Otherwise Classified ), accounts for recorded events that had no cause code assigned to them: Burn or exposure: includes hot or cold objects, chemical fire, welding, scalds, temperature exposure, and radiation. Caught in or between; include s caught in or between machinery, an object being handled, and miscellaneous objects such as earth slides or collapsing buildings. Puncture or cut: includes punctures, cuts, or scrapes as a result of broken glass, hand tools, utensils, power tools, appliances or guns. Fall, trip, or slip: includes falling from a different level or on the same level, ladder, scaffolding falls, s lipping on liquid or grease, ice or snow slips, and falls into openings. Vehicle related: includes collisions with another vehicle or fixed object, rollovers, rough riding, and airplane, wate r or rail vehicle crashes. Strain, jump or lift: includes jumping, twisting, holding or carrying objects, lifting, pushing, pulling, reaching, overexertion, and throwing. Hit against or step on object: includes moving machine parts, objects being lifted, sanding, or scraping operations, stationary objects, and stepping on sharp objects. Struck by object: includes falling or flying objects, hand tools or machines in use, coworkers, motor vehicles, moving machine parts and objects handled by others. All other claims (noc): in cludes animal and insect b ites, explosions, foreign body in eye, injury or stress from assault, ab sorption, injection or inhalation, and causes that occur over a period of time.

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37 To describe the nature of an injury or occupational illn ess, NCCI applies a nature code, divided into the follo wing nine categories. The nint h category, All Other Claims (NOC), designates injuries or illnesses that did not have a code assigned to them. Sprain or rupture; includes strains, dislocations, he rnias, organ ruptures, and trauma to joints or muscles. Bruise or swelling: includes contusio ns, broken blood vessels, and inflammation. Laceration or abrasion: includes sliv ers, lodged small objects, open wounds, scrapes, and needle sticks. Fracture: includes any breaking of a bone. Occupational disease: includes repeti tive motion, loss of hearing or sight, respiratory conditions, poisoning, mental disorders, radiation, heart disease, cancer, aids, carpal tunnel, and any di sease resulting from work related experiences. Amputation: includes a loss of limb that i nvolves bone, loss of part of an organ, enucleation, or severance of a body part. Burn or exposure: includes electric al shock, chemical burns, temperature extremes, freezing, sunburns, heat stroke, and lightning. Multiple injuries All other claims (noc): includes asphyxi ation, loss of circulation, infection, concussion, heart problems, vision loss, hearing loss, poisoning, fainting, and no physical or psychological injuries. A review of USDOL-BLS occupation injury and fatality data between 1992 and 2005 showed that the greatest percentage (s ee Figure 24) of all fatalities among all industries in the US (N = 84,414) during this duration resulted from injury to multiple body parts (n = 30,833; 36.53%). Fatal ities attributed to head injuries ranked second (n = 20,409; 24.18%) followed by injuries to the trunk (n = 16,241; 19.24%), body systems (n = 13,688; 16.22%), neck injuries (n = 1,730; 2.05%), lower extremities (n = 809; 0.96%), and injuries to upper extremities having the lowest rate of fatality among all the industries

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38 (n = 211; 0.25%). The construc tion industry showed a similar body part profile for fatal injuries during the same tim e period (see Figure 25). 24.18 % 19.24 % 2.05 % 0.96 % 0.25 % 16.22 % 36.53 % 0.58 % HeadTrunkNeckLower extremities Upper extremities Body systemsMultipleNonclassifiable Figure 24. Percentage of fatalities be tween 1992 and 2005 (All Industries). (USDOLBLS, 2006b 26.92% 14.39% 1.59% 0.62% 0.16% 20.84% 34.51% 0.96%HeadTrunkNeckLower extremities Upper extremities Body systemsMultipleNonclassifiable Figure 25. Percentage of fatalities betw een 1992 and 2005 (Construction Industry), (USDOL-BLS, 2006b) The construction industry exhibited a significantly higher proportion of all fatalities attributable to head, body systems, and unclass ifiable injuries than displayed by all other injuries between 1992 and 2005 (US DOL-BLS, 2006b) (see Table 21). Table 22 shows the chi square table comparisons of the proportion of specific body part regions attributed to nonfatal injuries by USDOL-BLS between the construction industry and all industrie s between 1992 and 2005. The construction industry showed a significantly higher proportion of nonfatal injuries attributable to injuries to the head and lower extremities than for all industries. The construction industry had a higher proportion of nonfatal eye injuries [ 4.94% (N = 127,392) of all non-

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39 fatal injuries in the construction industry ] than was shown among all industries [3.40% (N = 831,915) of all non-fatal injuries in all industries]. This difference was significant, (1, N = 27, 033,307) = 16,174.93, p < .001. Table 21. Body part region injured as a proportion of all fata lities between 1992 and 2005 All industries Construction industry df = 1, N = 100,477 Body part region N Proportion of total fatalities N Proportion of total fatalities p < Head 20,409 24.18% 4,32426.92% 54.67 0.001 Body systems 13,688 16.22% 3,34820.84% 205.25 0.001 Nonclassifiable 493 0.58% 1550.96% 30.56 0.001 Trunk 16,241 19.24% 2,31114.39% 211.08 0.001 Neck 1,730 2.05% 2561.59% 14.46 0.001 Lower extremities 809 0.96% 1000.62% 16.98 0.001 Upper extremities 211 0.25% 260.16% 4.45 0.05 Multiple body parts 30,833 36.53% 5,54334.51% 23.79 0.001 Total 84,414 100% 16,063100% Table 22. Body part region injured as a proportion of all non-f atalities between 1992 2005. All industries Construction industry df = 1, N = 100,477 Body region N Proportion of all non-fatal injuries N Proportion of all non-fatal injuries P < Head 1,625,927 6.65% 209,774 8.14% 8183.43 0.001 Lower extremities 4,988,516 20.40% 617,459 23.96% 17,960.72 0.001 Trunk 9,153,036 37.43% 874,286 33.92% 434.41 0.001 Upper extremities 5,607,231 22.93% 586,462 22.75% 40.11 0.001 Neck 425,886 1.74% 35,811 1.39% 1721.45 0.001 Multiple body parts 2,100,387 8.59% 204,258 7.92% 1316.84 0.001 Body systems 331,844 1.36% 26,088 1.01% 2,121.05 0.001 Nonclassifiab le 223,039 0.91% 23,303 0.90% 1.61 0.10 Total 24,455,866 100% 2,577,441 100%

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40 Head Injuries Head injuries included any injuries to the skull, scalp, brain, ears, eyes, nose, teeth, mouth, soft tissue of the head, and facial bones (Hannon, P. & Knapp, K., 2006, p. 123). Any combination of brain, scalp, skull with or without ears, eyes, nose, mouth, teeth, face, or neck are coded as multiple head injury, which also includes injuries to the head not otherwise classified. Because of the constantly ch anging conditions at worksites, the construction industry is particul arly hazardous with respect to head injuries (Janicak, C.A., 1998). Dangers to construction workers include falls from heights (Gillen, M. et al., 1997; Huang, X. and Hinze, J., 2003), being hit by falling or swinging objects, and collapse of buildings or trenches. Workers may be hit by falling bricks, or tools, fall from scaffolds or ladders, or fall through insu fficiently blocked holes in floors or roofs (Kines, P., 2002; Kisner, S. and Fosbroke, D., 1994). The chief causes for head injuries are motor vehicle accidents and falls (Anders on, D., Miller, J. and Kalsbeek, W.; 1983), also major causes of other injuries for cons truction workers. Falls and vehicle incidents and being struck by objects were identified as major sources of head injuries and of fatalities resulting from head injuries in the construction industry (US-BLS, 1997). Injury Types and Mechanisms Injuries to the skull include any injury to the cranial bones (see Figure 26). Although the skull is tough, resilient, and pr ovides excellent protection for the brain, a severe impact or blow can result in fr acture of the skull and may be accompanied by injury to the brain. Some of the diffe rent types of skull fractures include: Simple: a break in the bone without damage to the skin. Linear or hairline: a break in a cran ial bone resembling a thn line, without splintering, depression, or distortion of bone.

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41 Depressed: a break in a cranial bone (or crushed portion of skull) with depression of the bone in toward the brain. Compound: abreak in or loss of skin and splintering of the bone. Along with the fracture, brain injury, such as hematoma (bleeding) may occur. Figure 26. Position of the cranium (left) and bones of the cranium (right) (Source: ContMedia Human 3D Advan ced Internet Edition, 2007). The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly. It is us ually described as having five layers. Scalp injuries are usually the result of direct impact but may not be apparent in inflicted head injuries (Hannon, P. & Knapp, K., 2006, 1996, p. 124). When present, these may manifest as abrasion, bruising, laceration, or a burn. Punctu res of the scalp, skull and brain may result from penetrating objects such as nails from pneumatic nail guns (Buchalter, G.M., et al., 2002; Beaver, A.C. and Cheatham, M.L., 1999; Bo ck, H., Neu, M., Betz, P., and Seidl, S. 2001). Injuries to the brain include any brain concussion or brain da mage (Stone, D.J., 1996, pp. 11-1 11-30). The brain is divided into four main sections: cerebrum, brain stem, diencephalons and cerebellum (see Figure 27). The cerebrum controls deliberate actions and is also the center of intellig ence, learning and teaching ability, memory, will and feelings. The cerebellum coordinates m ovements, is responsible for balance and orientation in space. The brain stem cont rols (among other things) respiration, blood

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42 circulation, sleeping/waking rhythm and attention, and is di rectly or indirectly connected to all parts of the central nervous system. Types of injury to the brain may include anoxic brain injury, contusion/concussion, coup/contrecoup, diffuse axonal injury (DAI), or hematoma (epidural and subdural). An anoxic brain injury is caused by a lack of oxyge n to the brain. It usually results from lack of blood flow due to injury or bleeding a nd will cause swelling of brain tissue (Stone, D.J., 1996, p. 11-6). Figure 27. Structure and lobes of the br ain. (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Contusion or concussion is often mislabeled a mild injury to the brain resulting in bruising of brain tissue. This injury may cause headaches, vomiting, dizziness and problems with memory or concentration. It doe s not require surgery. While there is little or no loss of consciousness, the long-term re sults certainly may not be mild. A coup injury is caused when the brain is propelled ag ainst one side of the skull. Because brain tissue is suspended in fluid, it often rebounds and collides with th e opposite side of the skull. When it strikes both sides of the skull, the injury is sometimes called a contrecoup injury.

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43 Diffuse axonal injury (DAI) results when a rotational or shearing force is exerted on the nerve fibers (Hannon, P. and Kna pp, K., 2006, p. 131). DAI may cause a loss of consciousness, or coma, which may last from a short time to an indefinite period. Epidural hematoma is an accumulation of blood between the skull and the top lining of the brain. This clot may cause pr essure changes in the brain, and emergency surgery may be necessary. The size of the clot will dictate the necessity of surgery. This bleeding may increase pressure on the brai n, causing it to be forced down the spinal column, compressing the brain stem and resulti ng in death. An intracerebral hemmorhage is a blood clot deep in the middl e of the brain that is hard to remove. Pressure from this clot may cause tissue damage, and surgery ma y be needed to relieve the pressure. A subdural hematoma refers to the formation of a blood clot between the brain tissue and the dura. If it occurs slowly over several week s it is referred to as a subdural hematoma; if it occurs quickly it is re ferred to an acute subdural hematoma. The clot may cause pressure and require surgical removal. Injuries to the ear include any injury to th e outer ear, middle ear, inner ear, and/or results in partial or complete loss of hear ing. The outer ear includes the auricle and the auditory canal. The middle ear includes the tympanic membrane (eardrum), eustachian tube and tympanic cavity. The Eustachian tube, which creates a connection to the nasopharyngeal space, opens out into the tymp anic cavity. The tympanic cavity is a space filled with air, which is lined by a mucous membrane. Its three auditory ossicles are named after their appearance: hammer, anvil an d stirrup (see Figure 28). This assembly is responsible for the transmission of sound (Stone, D.J., 1996, pp. 10-3 10-30).

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44 Figure 28. Structure of the ear (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Ear injuries can occur in a va riety of ways. A forceful, dire ct blow to the side of the head can increase air pressure inside the ea r canal, leading to a ruptured eardrum or a disruption of the tiny bone s in the inner ear that transmit sound. Extremely loud, explosive noises can increase the air pressu re inside the ear canal and damage the eardrum (acoustic trauma). Dramatic decrea ses in atmospheric pressure changes can cause the eustachian tube to compress, which prevents air from entering the middle ear (Stone, D.J., 1996, pp. 10-7 -10-11). This leaves the middle ear unable to compensate for the change in pressure outside the ear. Kilburn, Warhsaw and Hanscom (1992) concluded that there was a link between hearing loss, attrib utable especially to the use of air impact power tools, and balance dysfunction among construction iron workers, thus increasing the risk of falls from heights. Injuries of the inner ear can occur to welders, when molten metal and a hot spark fall into the ear while welding. This injury can cause deafness as well as facial nerve injury (Panos ian, M.S. and Dutcher, P.O., 1994). Cuts or scrapes may injure the outer ear or ear canal. Aggressi ve or inappropriate techniques when cleaning the ear canal can ca use irritation or injury. Burns or frostbite can cause ear injuries. Objects placed fo rcefully in the ear can cause injury.

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45 Injury to the eye includes any compromise to the eye and/or optic nerve (visual organ) which may or may not result in a part ial or complete, temporary or permanent, loss of vision (Welch, L.S., et. al., 2001; Li pscomb, H.J., et. al., 1999). The visual organ consists of the two eyeballs with the visual nerves and the corresponding cranial nerve tracts, together with different adjuvant features such as th e eye muscles, the eyelids and the lacrimal system with the tear glands (see Figure 29). Eye injuries comprise a significant proportion of all construction work re lated injuries (Welch, L.S., et. al., 2001). Welders and carpenters are at pa rticular risk for eye injuries (Lombardi, D.A. et al., 2005; Lipscomb, H.J., et al., 1999) Figure 29. Structure of the eye.(Source: ContMedia Human 3D Advanced Internet Edition, 2007). Eye injuries range from the very minor, to the catastrophic, resulting in permanent loss of vision. Eyes may be subject to inju ry due to chemical exposures and/or burns. These are often the result of a splash of li quid getting in the eye (Welch, L.S., et al., 2001). Chemical burns can occur in a number of ways. Many chemicals are simply irritants to the eye and do not usually cau se permanent damage. However, acids and alkalis are highly caustic and can cause se vere damage (Islam, S.S., et. al., 2000).

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46 The cornea is somewhat of a transparent skin that covers the eye. A corneal abrasion is a scratch or an abrasion of that sk in. Corneal abrasions of ten result from being "poked" in the eye, often from a finger, tr ee branch, or other foreign object. Traumatic iritis (inflammation of the iris) can occur in the same way as a corneal abrasion. However, this injury is more associated with a blow to the eye fr om a blunt object, such as a fist or a club. The iris is a muscle that controls the amount of light that enters the eye through the pupil (Can tMedia, 2007). Hyphemas result from bleeding in the eye that occurs in the front part of the eye, in the space between the cornea and the iris. Orbital blowout fractu res are cracking or breaks of the facial bones su rrounding the eye. These inju ries are associated with significant force from a blunt object to the eye and surrounding structures. Lacerations (cuts) to the eyelids a nd the conjunctiva (mucous membranes) commonly are caused by sharp objects but can al so occur from a fall. Lacerations to the cornea and the sclera are very serious and are frequently associated with blunt trauma of flying objects. Foreign bodies in the eye could be any objec ts that get into the eye. Corneal foreign bodies become embedded in th e cornea but have not penetrated the eye itself. Metal foreign bodies in the cornea can cause a rust stain, which also requires treatment. Intraorbital foreign bodies are in the orbit (or eye socket) but have not penetrated the eye. Intraocular foreign bodies are injuries in which the globe of the eye has been penetrated by the objec t (Dannenberg, A.L., et. al., 1992). The cornea (the clear window of tissue on th e front of the eyeball; see Figure 110), can be damaged easily by exposure to ul traviolet radiation from the sun and from other sources of ultraviolet light, such as a we lder's arc or even a halogen desk lamp. The

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47 cornea takes the brunt of the damage if proper eye protection is not worn. A corneal flash burn (also called ultraviolet keratitis) can be viewed as a sunburn of the eye surface. Corneal damage from a corneal flash burn ma y cause pain, temporary reduction in vision, or permanent partial or complete loss of vision (Islam, S.S., et. al., 2000). The nose serves primarily to moisten, warm and clean the air to prepare it for the lungs. The nasal sinuses are also involved in this. At the same time, the nose is also a sensory organ because this is where the olf actory organ is located. The structure of the outer nose consists of the root of the nose (radix nasi) to wh ich the bridge of the nose is attached (see Figure 210). This is held by the nasal bones. The sides of the nose extend to either side of the bridge of the nose and fo rm the nostrils in combination with the tip of the nose consisting of cartilage. Figure 210. Structure of the nasal cav ity. (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Injuries to the nose include all injuries to the external area of the nose and internal components of the nose. Injuries to the internal na sal location would in clude injuries to the nasopharynx, nasal passages, sinuses, injuri es to multiple internal nasal locations and any internal nasal location not otherwise classified. Nasal in jury results from fractures,

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48 dislocations, foreign bodies, chemical irrita nts, or burns. Construction workers are at higher risk for all facial injuries, including those to the nose. Falls from a height and being struck by an object are the most common causes of these injuries (Lipscomb, H.J., et al., 2003 & 2006; Exadaktylos, A.K. et al., 2001). All severe blows to the nose may result in a nasal fracture (Harrison, D.H., 1979). After such a blow, the nose may appear slight ly deformed as well as shifted laterally or depressed. Other symptoms include: pain, swel ling, airway obstruction, epistaxis (profuse bleeding from the nose), crepitance (the cr ackling heard and the sensation felt when broken bones are moved over each other), ecchymosis (a purplish area of the nose resulting from fracture and caused by extrav asation of blood into the skin), septal hematoma (a mass of extravasated blood confin ed within the nasal septum), rhinitis (an inflammation of the mucous membranes that lin e the nasal passages), and nasal vestibular stenosis (a narrowing of the na sal passages) (ContMedia, 2007). In addition to fracture, trauma may be caused by chemical inhalation. This is normally due to repetitive inhalation of toxic materials that may, in addition to irritating the nasal passages, cause damage to the lowe r respiratory tract and lungs. Irritant gases may cause damage by direct contact with me mbranes and a subsequent chemical reaction can result in membrane damage. Some common irritants that may be encountered in workplace include: cleaning solutions and pow ders, ammonia, environmental tobacco smoke, bleach, metalworking fluids, ozone, su lfur dioxide, paint thinners, arsenic, chromic acid, copper dust and mists (Frampton. M. and Utell, M. J., 1995). The mouth consists of the oral cavit y, with the teeth and the tongue (see Error! Reference source not found. 11). The lips close the cavity to the outside, and on the

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49 inside it borders on the throat (pharynx). The skin of the lips on the outside is hairless, without pigments and only slightly cornif ied. The highly vasculated derma has a red shimmer and gives the lips their red color. Numerous nerves make the lips sensitive to touch. The throat constitutes the connecti on to the openings of the digestive and respiratory systems. The upper part of the or al cavity, the roof of the mouth, is divided into the front hard palate and the rear soft palate (Hannon, P. and Knapp, K., 2006). The lower boundary of the oral cavity consists of the mandible, on which the tongue lies. The mucous membrane of the m outh secretes mucous, which together with the saliva from the salivary glands, keeps the insi de of the mouth moist. The oral cavity is held at the sides by the jaw muscles and at th e bottom by the muscles of the bottom of the mouth. In addition to the oral cavity's tasks involved in ta king in food, testing it (taste), crushing it with the teeth and tongue and preparing it for dige stion with certain salivary enzymes, it is also involved in phonation (speech). Figure 211. Front and side view of the structure of the mouth. (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Mouth injuries may involve the teeth, jaw, lips, tongue, inner cheek s, gums, roof of the mouth (hard or soft palates), or tonsils. Even a small cut or punc ture inside the mouth

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50 may bleed profusely because there are many bl ood vessels in the head and neck area. Teeth may be injured during a fall or when struck by an object when performing an occupational activity. A tooth may be knocked out (avulsed). An injury could crack, chip, or break a tooth, or make a tooth change colo r. A tooth also may be loose or moved in position (dental luxation) or jammed into th e gum (intruded) (Hannon, P. and Knapp, K., 2006, p. 128). An injury to the mouth or lips may cause a large, loose flap of tissue or a gaping wound that may need stitches. The piece of sk in between the lips and gums or under the tongue may tear or rip. Usually this type of injury will heal wit hout stitches. It is generally not a concern unless the tear was caused by physical trauma. An injury to the roof of the mouth, the back of the throat, or a tonsil can injure deeper tissues in the head or neck. These injuries can happen when a worker falls with or onto a pointed object, such as at the end of rebar. Neck Injuries Injuries to the neck include injuries to the middle and lower throat (vocal chords, larynx, laryngopharynx, pharynx), windpipe (trachea) any multiple internal neck injuries, and any internal neck injury not receiving a spec ific classification. Inju ries to the external area of the neck and throat are also classified as neck injuries. Neck injuries would also include any injury to the spinal column bone in the neck, which includes the first seven bones of the spinal column (C1C7: cervical vertebrae), discs (spinal column cartilage in the neck), and injury to nerve tissue in the neck (spinal chord). The most common injuries to the neck among construction wo rkers include sprains and musculoskeletal pain, as well as contusions, abrasions and impalement from foreign bodies (Hunting, K.L., et al., 1999). Injuries to the spinal column are usually life threatening. Foreign

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51 bodies intruding the neck area, such as thos e produced from nail gun accidents can also present a great threat to lif e (Buchalter, G.M., et al., 2002; Beaver, A.C. and Cheatham, M.L., 1999). Throat & Trachea The throat is a tube-like st ructure about 12 cm in length, which is divided into three sections. These are the upper throat (nasal pharynx), the middle thro at (oral pharynx) and the lower throat (laryngeal pharynx). The mi ddle section and lower section belong to the esophagus. The respiratory section consists of the upper part and th e middle section. This means that the windpipe (trachea) and epig lottis cross in the middle section. When swallowing, the air passage is interrupted by the soft palate the base of the tongue and the epiglottis. Vertebrae of the Neck (Cervical Vertebrae) The human vertebral column is on the rear side of the body. Its main functions are to support the body, to cushion it (especially to protect the brain against shocks) and to protect the spinal cord. The human vertebral column consists of 33-34 vertebrae, which are designated according to the region of the body in which they are found (Hannon, P. and Knapp, K., pp. 111-115). The cervical verteb ral column has 7 cervical vertebrae (C1C7). The cervical vertebral column can be inclined approximately 90 degrees backwards, 40 degrees forwards and 35 degrees to the side (see Figure 212). The individual vertebrae are separated fr om one another by intervertebral discs. They function like shock absorbers. Various ligaments between the vertebral processes cover almost the entire vertebral column.

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52 Figure 212. Vertebrae of th e neck (left) and structure of the vertebral column (right).(Source: ContMedia Human 3D Advanced Internet Edition, 2007). Injury Types and Mechanisms Common injuries to the neck include musc le spasms, which are tight, contracting movement of the muscles in the neck. Neck spasms are often the result of injury and overuse. A muscle strain is a tear in the sm all muscle fibers that slide over one another during movement to produce contraction. Sometimes this tear can be microscopic, or can cause bleeding or overstretched fibers. Mu scle strains are often caused by overuse, a sudden and strong usage including whiplash and sudden contact with objects, or too much tension (e.g., lifting heavy weights). Mu sculoskeletal injuries of the neck are common among construction workers (Schneider, S.P., 2001). At higher risk of these strain injuries of the neck are crane operat ors, painters and insu lators (Holmstrom, E., Moritz, U., and Engholm, G., 1995). The neck is quite vulnerable to fractures. A fracture is a break in a bone. Neck fractures must be taken very seriously, because of the risk of a broken neck, and paralysis of the body below the site of the inju ry. Paralysis happens when the spinal cord becomes damaged due to the injury (Hannon, P. and Knapp, K., 2006, pp. 111-115). Lesser neck fractures might cause pain, tin gling, numbness or varying degr ees of paralysis. Impact

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53 such as from car crashes, falls, sudden imp acts with objects or people are common causes of occupational neck fractures. Trunk Injuries Trunk (ventral body cavity) injuries include any injury to the upper and lower back, spinal column cartilage in the back, spinal chord, thorax (chest), sacrum and coccyx, and pelvis. This would also include injuries to the exterior poster ior of the pelvis and hip area (e.g., buttocks). Trunk injuries also incl ude injury to internal organs (see Figure 213) of the thorax (heart and lungs), abdom en (s tomach, lower esophagus, small or large intestines, liver, gall bladder, spleen, pa ncreas, kidneys, appendix) and groin. Multiple trunk injuries include those injuries which effect any combination of the hip, abdomen and chest (Hannon, P. and Knapp. K., 2006, pp. 151-159). A large portion of occupational injuries to the trunk are a resu lt of blunt trauma, which can range from minor to fatal. It is not uncommon for some trunk injuries, even severe ones, to go undiagnosed for quite some time. The liver, spleen and kidneys are the most commonly injured organs of the abdomen. Injuries of the Thoracic Cavity Unlike the abdomen the thorax is less co mplicated, containing far fewer organs which allows for injuries in the region to be more predictable. However, injuries within the thoracic area often present themselves as the most life threatening (apart from the brain). The thorax is the s uperior portion of the ventral body cavity, separated from the abdominal cavity by the diaphragm. In general, the thorax is a hard shell containing the following components: the heart, lungs, trach ea, esophagus, aorta, and other major blood vessels. The ribs and the sternum (see Figure 2-13) surround the entire cavity, providing a protective shell, and along w ith the diaphragm and intercostal muscles, facilitate

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54 breathing (see Figure 214). The intercostal musc les consist of two layers, and the fibers cross each other almost at right angles. The intercostal muscles starting at the inner edge of the costal arches are referred to as inner muscles. They lower the ribs on breathing out. The outer intercostal muscles lift the ribs on breathing in. Finally, th ere is another group of intercostal muscles, the innermost. They are separated from the inner muscles by the intercostals nerves and are also respirat ory muscles (ContMedia Human 3D Advanced Internet Edition, 2007). Figure 2-13. Side view of thorax (ribs, lungs and diaphragm). (Source: ContMedia Human 3D Advanced Internet Edition, 2007). The thorax is generally more difficult to in jure due to the protected nature of the cavity. Approximately 75 percent of all thoracic injuries o ccur along with injuries to other cavities, mainly the skull or abdomen (Ghista, 1982). The impact mechanisms for blunt trauma in juries of the thorax are essentially the same as that for the abdomen (Hannon, P. and Knapp, K., 2006, p. 158). Fracturing of the bone structures can cause compression and even tual puncture of the nearby organs. Shear forces resulting from deceleration and conse quent tissue strain may cause tearing a fixed attachment point. An increase in internal pressure within the thoracic cavity can result in bursting or rupturing of organs and tissues.

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55 Ribs and Sternum The sternum is a flat bone with three segments connected by strong connective tissue and cartilage (see Figure 2-16). There are twelve sets of ribs. Ribs 1 to 7 connect directly to the sternum. They also connect to the thoracic vertebrae (Hannon, P. and Knapp, K., 2006, pp. 162-163). Ribs 8 to 10 attach only to the cartilage of rib 7, and ribs 11 to 12 have no direct connection at all to the sternum (see Figure 214). Figure 214. Detail of the st ernum (left) and ribs 1 to 12 (right). (Source: ContMedia Human 3D Advanced Internet Edition, 2007). The rib cartilage allows for a large amount of bending strain before fracture occurs. Because ribs 1 and 2 are also protected by th e shoulder, they are difficult to fracture. When these ribs do fracture, there are almo st always additional injuries. The most frequently fractured ribs in occupational se ttings are 5 to 9 (Islam, S.S. et al., 2001). There are two types of bending rib fractures: a direct bending where fracture occurs at the impact site and an indirect bending where a load is transmitted to a w eaker part of the rib (Schmidtt, K, Niederer, P. and Walz, F., 2004, p. 95). When there are four or more complete rib fractures, the chest wall becomes unstable, a condition that is termed flail chest. This causes a paradoxical movement

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56 upon patient inhalation, preventing the lung from properly filling with air. A serious flail chest can be fatal unless resp iratory assistance is provided. Heart and Thoracic Blood Vessels The heart has two major anchor points: th e diaphragm at the apex and the major vessels at the superior end (s ee Figure 215).Penetrating tr auma directly to the heart causes extensive bleeding and usually deat h. Blunt trauma can include temporary electrical irregularities, comple te myocardial infarction (i.e., heart attack caused when an area of heart muscle dies or is permanently damaged because of an inadequate supply of oxygen), contusions, lacerations, embolism (s udden interruption of blood flow) from thrombosis (clot), partial tearing of the tissue, or rupture (Hannon, P. and Knapp, K., 2006, p. 163). Figure 2-15. Position of the hear (left) and structure of the he art with cross sectional view (right). (Source: ContMe dia Human 3D Advanced Internet Edition, 2007). The mechanisms for these injuries can in clude puncture from a rib or sternum fracture, compression of ribs and adjacent orga ns without rib fracture, or tension loads resulting from lengthening deformation of th e heart (Schmidtt, K., Niederer, P., and

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57 Walz, F., 2004, p. 97). Any injury in which th e heart bleeds openly and is unable to continue circulating blood is usually fatal. Rupture and laceration are the most likely mechanisms resulting from blunt trauma to the thorax. The most common mechanisms of injury were found to be motor vehicle crashe s followed by falls and struck by accidents (Ochsner et. al 1989). Exposures to various materials and activitie s, such as welding (Sjogren, B., et al., 2002) in construction may increase a workers risk of developing various types of heart disease. The most prevelant form of heart dise ase is myocardial infarction (heart attack). In an occupational setting, heart disease must be evaluated with a view to both background and precipitating factors (Hannon, P. and Knapp, K., 2006, pp. 163-164). Background factors include such factors as smoking, family history, and preexisting illnesses which further potentiates heart disease (e.g. diabetes and hypertension). Precipitating factors (occupationally event base d) include noise, h eat and cold, shift work, and emotional stress. The heart ma y also be damaged by toxic substances. Precipitating factors for a h eart attack can include physical overexertion, excessive heat or humidity and emotional crisis. Construction work in general has shown a high risk of death and permanent disability due to heart disease. Specific construction occupations that are at high risk for death a nd permanent disability due to heart disease include laborers, carpenters, and electric ians (Leigh, J.P. and Miller, T.R., 1998). Trachea, Esophagus and Diaphragm Injuries to the respiratory system mainly concern lung injuries. In juries to the lungs are the most common thoracic injury and can range from minor to fatal (Schmidtt, K., Niederer, P. and Walz, F., 2004, p. 96). Th e lungs are commonly lacerated by rib fractures (see Figure 216). If substantial, the laceration ma y lead to the development of

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58 minor to serious pneumothorax (collection of air or gas in the space [pleural cavity] surrounding the lungs) which prevents the lung from fully expandi ng upon inhalation. A similar lung injury that occurs from either penetrating trauma or rib puncture is the hemothorax (a collection of blood in the spac e between the chest wa ll and the lung). Figure 216. The larynx, pulmonary lobes and bronchi of the lungs, and diaphragm. (Source: ContMedia Human 3D Ad vanced Internet Edition, 2007). This has similar effects as a pneumothorax by preventing the full expansion of the lung. It is also possible to have a hemo-pneumot horax, where both blood and air invade the pleural cavity. Other injuri es of thoracic organs include ru pture of the trachea, rupture of the espohagus, and laceration of the diaphragm. The latter possibly results in a partial protrusion through a weak point or tear in the thin muscular wall that holds the abdominal organs in place (hernia). Because construction work exposes workers to a greater risk of falls and struck-by incidents, they are highly susceptible to traumatic injuries of the lung and surrounding tissue. Liver The liver is the largest gland in the b ody, as well as the largest abdominal organ (see Figure 217). The liver is responsible for a large number of essential body functions, including metabolism of carbohydrates, lipids, and proteins; blood plasma synthesis;

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59 vitamin and mineral metabolism; digestion; and the removal of certain toxins, hormones and bacteria from the body. Lacerations and blunt trauma to the liver are the most dangerous abdominal injuries. Lacerations may occur from direct impact compression, puncture from rib fractures, deformation due to compression of other organs, or increased blood flow pressure upon impact (Hannon, P., and Knapp, K., 2006, p. 155). Figure 217. The position (left) in the human body, and the ex terior structure (right) of the liver. (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Spleen The spleen is the most commonly injured organ of the abdomen from blunt trauma (Schmidtt, K., Niederer, P., and Walz, F ., 2004, pp. 113-115). It is pa rtially protected by the lower left rib cage and is the largest lymph organ and is the site for red blood cell storage. The spleen also filters bacteria and cellular debris from the blood. Being a highly vascularized organ, when ruptured or dama ged, fatal hemorrhaging in the spleen may result. Injuries to the spleen range from mi nor non-bleeding capsular injuries to multiple lacerations and extensive hemorrhaging (see Figure 218).

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60 Figure 218. Positions of the spleen kidne ys and pancreas in the human body. (Source: ContMedia Human 3D Advan ced Internet Edition, 2007). Kidneys The two kidneys are located in the lumbar region (see Figure 218), on both sides of the spinal column behind the connective tissue of the a bdominal cavity, protected by the lower ribs. Because of their location, the ki dneys are more susceptible to side and rear direct impacts. The kidneys have no ligament structure to hold them in place. The renal veins and arteries serve as their primary att achments to the abdominal aorta and inferior vena cava (Hannon, P. and Knapp, K., 2006, p. 156) Such attachments make the kidneys highly vulnerable to stretch injuries of the blood vessels and potential detachment. The function of the kidneys is closely linke d with the vascular system. The kidneys control the balance of salts and minerals, re gulate the balance of liquid and are also involved in adjusting the levels of acids and alkalis in the body. So the main task of the kidneys is to maintain the constant balance of the normal composition of the blood and therefore all other body fluids. The kidneys mu st recognize and decide which substances need to be excreted and which have to stay in the purified blood in the body. Injuries of the kidneys can be as minor as a contusion but have the potential to be fatal if there are

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61 extensive lacerations or, as previously desc ribed, if a detachment injury occurs. In extreme cases, kidney failure is possibl e (Hannon, P. and Knapp, K., 2006, p. 156). Pancreas The pancreas serves two functions. It aids in digestion and produces hormones that regulate glucose metabolism (Hannon, P. a nd Knapp, K., 2006, p. 156). The pancreas is fairly deep within the abdominal cavity and is fairly well protected from injury due to the surrounding tissues (see Figure 218). Pancreatic injuries account for 1 to 2 percent of the abdominal injuries (Yoganandan et. al., 2001). However, pancreatic rupture can occur in either compression or shear, particularly against the spinal colum n. Because this injury normally occurs with other abdominal injuries, pancreatic injuries often get overlooked. An extreme delay in detection can lead to serious illness. Stomach The stomach is a large, hollow organ located in the middle region of the abdomen (see Figure 219). While it is not uncommon to see stomach a injury due to a penetrating wound, a stomach injury due to blunt trauma is infrequent and typically not life threatening. The stomach is highly compressibl e and resistant to bur sting. Because of the extremely low levels of bacteria present in the stomach, any rupture is unlikely to cause infection in the peritoneum (membrane lining of the abdominal cavity). Contents of the stomach may explode through the esophagus and mouth following a high magnitude blunt impact. This may result in mild irrita tion to the linings of the esophagus and mouth (Hannon, P., and Knapp, K., 2006, p. 157).

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62 Figure 219. Positions of the organs of the lower digestive system in the human body. (Source: ContMedia Human 3D Ad vanced Internet Edition, 2007). Small and Large Intestine The small and large intestines travel thr ough most of the central and lower portions of the abdominal cavity (see Figure 219). The small intestine is the portion of the digestive system most responsible for ab sorption of nutrients from food into the bloodstream. Located around the periphery of the small intestine, the large intestine consists of the cecum, appendix, colon (ascending and descending), rectum, and the anal canal (anus). The large intestine is the portion of the digestive system most responsible for absorption of water from the indigestib le residue of food (Hannon, P., and Knapp, K., 2006, p. 157). Similar to the stomach, the potential fo r compression or burst in the duodenum increases when it is full and blunt trauma is possible. The structures of both the small and large intestine are fairly moveable within the cavity and yield well to compressive and tension loads. The most frequent blunt trauma injury to the small intestine is a shearing tear near the large intestine attachment due to deceleration or an acute compression tear.

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63 However, it is generally a penetrating wound, from a sharp object, that re sults in injury of the small intestine (Schmidtt, K., Ni ederer, P., and Walz, F., 2004, p. 117). Like the small intestine, the large intestine is more frequently injured by penetrating trauma. However, because it has se veral anchor points to the abdominal wall and other organs, a rupture of the transver se colon may also occur from compression against the spinal column. Blunt trauma injury to the colon comprise s about 5 percent of all abdominal injuries repor ted (Yoganandan et. al., 2001). Abdominal Wall It is possible to tear the lining of th e abdominal wall without injuring any other organs. However, a complete tear may lead to a traumatic hernia, where various organs may be pushed outside the cavity itself. De pending upon the degree of extrusion of the traumatic abdominal hernia a nd the degree to which blood flow to organs is reduced or eliminated, the severity of the injury will vary (Stone, D.J., 1996, pp. 9-5 9-18). Gall Bladder The gall bladder is a storage site for the bile that is secreted in the liver, with a common duct that empties into the duodenum. The gall bladder is well protected from injury, being located inferior and posterior to the liver (see Figure 220). Injuries to the bile ducts can occur with a cr ushing blow to the posterior torso. Another possible, though not highly probable, injury mechanism descri bed by Yoganandan et al. (2001) is that the bile duct may be ruptured upon the rapid empt ying of the gall bladder into the common duct coupled with a simultaneous sheari ng force during distention of the duct.

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64 Figure 220. Position of the gall bladde r. (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Urinary Bladder The urinary bladder is located on the floor of the pelvic cavity (see Figure 221). The muscle tissue of the bla dder is highly distensible. The empty bladder has strong, thick walls that become thinner as the bladder fills. As the bladder fills, it places pressure on the peritoneum. The potential for injury in creases as the bladder continues to extend. Any sudden increase in lower abdominal pre ssure due to a compression load may cause a distended bladder to rupture at the weakes t point, similar to a balloon (Hannon, P., and Knapp, K., 2006, p. 158). Figure 221. The position of the urinary bladder. (S ource: ContMedia Human 3D Advanced Internet Edition, 2007).

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65 Reproductive Organs (Male & Female) The female uterus, a strong hick-walled ho llow organ remains fairly tolerant to blunt impact forces until a woman become s pregnant. A woman s ovaries are well protected deep in the pelvic cavity and are often not subject to injury. The pregnant uterus, however effectively changes the vulnerabi lity of the uterus as well as other organs to injury. By putting other organs under strai n, it is easier to injure other organs through blunt impacts that might in th e absence of the fetal state, be minor. A full-term fetus occupies much of the abdominal cavity. This is of particular concern in motor vehicle accidents and falls. It has been suggested that modifications to seat belts and steering wheel positioning could be made to better accommodate pregnant drivers (DeSantis et. al., 1999). The organs of the male reproductive system are located outside the lower abdominal cavity. Such an exterior location ma kes both the penis and testicles susceptible to trauma resulting from impact with a blunt object or puncture resulting from penetration by a sharp object (Stone, D.J., 1996, p. 14-5). Pelvis The pelvis links the lower extremities to th e spine. The pelvis is a ring of bones basically composed of four bones: two hipbones (ilium) form the side and front walls while the sacrum and the coccyx form the rear wall (see Figure 222). Mechanically, the pelvis provides the only path to transmit the weight of the trunk to the ground. The hipbones consist of three fused bones (ilium ischium, pubis) and also host the acetabulum, which is the cup-shaped articular cavity forming one part of the hip joint. The pubic bone and the pubic symphysis form th e frontal part of the pelvis. The pubic bones are often subject to injury (Hannon, P., and Knapp, K., 2006, pp. 257-262).

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66 Figure 222. The bones of the pelvis. (Source: ContMedia Human 3D Advanced Internet Edition, 2007). Located at the rear wall of the pelvis, the sacrum is a fusion of the sacral vertebrae with sacral nerve (e.g. the sciatic nerve) th at arise from the sp inal cord passing the sacrum. Major blood vessels are also locat ed near the sacrum and the coccyx. Fractures of the pelvis bone s, resulting from falls or struck by (usually motor vehicle) are the most common injuries sustai ned in accidents. Injuries to the pelvis are categorized clinically as isolat ed fracture of the pelvic ring, multiple fracture of the pelvic ring, sacrum fracture and associat ed injuries. Sacrum fracture occurs in extensive pelvic injuries. Sacral nerves are often in danger of injury in these types of injury. Additional injury, especially hemorrhage, can be associ ated with pelvic fractures (Schmidtt, K., Niederer, P., and Walz, F., 2004, pp. 114-116). Due to the fact that the pelvis and th e proximal femur (see Figure 2-22) are often injured simultaneously, such injuries are co mmonly referred to as hip injury, thus

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67 fractures involving the proximal part of th e femur are commonly call hip fractures. The hip is frequently injured in falls. A lateral loading on the hip commonly causes the femur neck to fracture. Dislocation of the hip joint can result from lateral impact. From a biomechanical point of view, the underlying mechanisms of pelvic fracture are either compression, vertical shear or a combination thereof. If the pelvis is subjected to vertical loading, shear can cause fracture as well as ruptur e of ligaments (Schmidtt, K., Niederer, P., and Walz, F., 2004, pp. 125-132). There are four possible types of fracture mechanisms: direct loading, indirect lo ading, repetitive load ing and penetration. Thoracic and Lumbar Spine (Thoracolumbar Spine) Injuries to the trunk include any injury to thoracic (T1-T12) and lumbar vertebrae (L1-L15) (see Figure 223). Injuries to the thoracolum bar spine tend to be minor compared to cervical spine injuries. Back pa in is commonly reported after various types of collisions and severe injuries to the spinal cord can occur. Injuries to the soft tissue of the thoracolumbar spine are also common. The so ft tissues involved are the intervertebral discs, the various ligaments, the facet join ts, the muscles and te ndons attached to the vertebral column. A usual complaint of this t ype of injury is lower back pain. Incidents provoking this complaint range from minor re ar-end collisions in motor vehicles to severe impacts from struck by material or falls. In some cases the back pain is associated with disc rupture or disc bulge. Such injuries are gene rally the result of a slow degenerative process commonly associated w ith repetitive motion mechanisms (Stone, D.J., 1996, pp. 6-6 6-43)

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68 Figure 223. Side view of the vertebral co lumn. Each vertebra is numbered according to the part of the spine it is in, e.g., the lumbar vertebrae are L1 through L5. (Source: ContMedia Human 3D Ad vanced Internet Edition, 2007). Upper Extremities Injuries to the upper extremities, though ge nerally not life threatening, nonetheless can cause long-term impairment associated with significant costs (Mital, A., Pennathur, A., and Kansal, A., 1999). Generally the upper extremities can be divided into four different parts: the shoulders (or shoulder gi rdle), the arms, the forearms and the hands (includes wrists) (see Figure 224). The shoulder is comprised of the scapula, clavicle, and the join t articulations that attach the upper extremities to the torso. The arm is formed by the humerus and is linked to the shoulder by the shoulde r joint which is probably the most mobile joint in the human body. The elbow joint connects the arm to the forearm which consists of the ulna and the radius. The wrist joint, finally, c onnects the forearm to the hand. Associated muscles and soft tissue complete the four parts of the extremitiesStone, D.J., 1996, pp. 24 2-9).

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69 Figure 224. Bones of the upper extremities (Modified from ContMedia Human 3D Advanced Internet Edition, 2007). Types and Mechanisms of Injury The major mechanisms of injury to the upper extremities are falls, blows, exertion (such as lifting), and repetitive motion (Mit al, A., Pennathur, A., and Kansal, A., 1999). Falls are a common hazard in many construc tion occupations. Falls on an outstretched hand may produce any of several skeletal injuries including fractures of the wrist, radius, ulna or humerus, as well as ligamentous a nd muscle injuries. Falls directly on the shoulder or elbow may produce seri ous fractures or dislocations. Blows (e.g. being struck by a moving obj ect) to the elbow or arm are also a common mechanism of injury. Being caught in between or within pieces of equipment is another source of injury. Repetit ive motion injuries (overuse), repetitive stress injuries and cumulative trauma disorders are increasing ly identified as s ources of occupational injuries (Muggleton, J.M., Alle n, R., and Chappell, P.H., 1999). Contusions (bruises) and lacerations (cuts) are often only skin injuries. Significant injuries of this type are most often associated with deeper injuries such as fractures or damage to nerve or tendon. Occupational burns to upper extremities are common and include thermal (scalds, flash and contact burns), chemical, microwave and electrical burns (Stone, D.J., 1996, pp.

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70 2-13 2-15). Thermal and chemical burns are more common on the hand. Electrical burns usually involve the hand as the point of entry, but a great deal of tissue may be damaged as the current passes through the upper extremity. Chemical burns may be caused by organic a nd inorganic acids, al kaline substances and phosphorous. Workers in steel production an d manufacturing facilit ies are subject to frequent exposure to sulfuric and nitric ac id while hydrochloric acid is often present in areas where chemical and refinery work is being done. Construction workers may also be at risk of alkali burns from ammonium hydroxide, potassium hydroxide and sodium hydroxide (Vannier and Rose, 1991). Major vascular injuries to the upper extr emities include vessel lacerations, which may accompany any severe open injury, fract ure or laceration, and the compartment syndrome, in which pressure builds up in the tissue, compressing the arteries and blocking off (occlusion) the blood supply to the muscles and nerves of one of the compartments of the upper limb (Mital, A., Pennathur, A., and Kansal, A., 1999). Crushing injuries of the upper extremities ar e most often associated with different types of equipment and machinery, such as c onveyor belts, gears and pistons, industrial presses, and the handling of heavy materials. Most crushes are such where the skin remains intact. However, the internal damage may still be extreme. Crushing injuries may produce severe arterial damage through rupture, spasm or clotting (thrombosis). There is frequently severe muscle injury associat ed with crushing inju ries, which is often sufficient to produce compartment syndrome from swelling alone. Nerves are often damaged as a result crushing injuries. The bone fractures that occur in crushing injuries

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71 usually fracture multiple bone fragments (B utler, R.J., Durbin, D.L., and Helvacian, N.M., 1996). Fractures of the upper extremities are rela tively common and frequently the result of falls, particularly on the outstretched arm. Falls may fracture any bones in the upper extremity, depending on the type of fall and the age of the person. Shoulder fractures may also be caused by falling objects (Hannon, P., and Knapp, K., 2006, pp. 239-240, 247, 252-253). Construction workers are particularly susceptible to these injuries; typically a hand tool or other piece of equipment is acci dentally dropped or kicked off a scaffold above (Islam, S.S., et. al., 2001). Joint injuries to the upper extremities are common (Mital, A., Pennathur, A., and Kansal, A., 1999). The shoulder is particularly vulnerable and is the most frequently dislocated joint in the body. Joint injuries vary in severi ty, but they primarily affect the ligaments and other soft tissue structures that stabilize the joint. Ligament stress or strain is referred to as a sprain, which does not alter the bones of the jo int but may render the joint very unstable. Joints may also experi ence a dislocation in wh ich the joint surfaces are no longer in congruity (the ball is out of the socket). Tendon injuries, not of the hand, are usually the result of a chronic combination of overuse and degeneration due to aging. Tendon injuries may also occur acutely, following a laceration, or may suddenly ruptur e following chronic wear and tear. The two major sites for tendon injury in the upper extremities, excluding the hands, are the rotator cuff of the shoulder and at the elbow. Infl ammation of a tendon (tendonitis) may develop at the shoulder or the elbow. Tendon ruptures are rare but do occur during acute episodes of trauma. The biceps tendon can rupture at the shoulder and at th e elbow. Repeated

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72 overhead lifting is thought to be an important factor in rupture as well as tendonitis of the bicep at the shoulder. Triceps tendon ruptures are very rare and are generally caused by a fall or blow. Tendon lacerati ons are common in the hands, where the tendons are abundant and superficially located. In the ar m, a deep laceration may cut a tendon (Gerr, F., Letz, R., and Landrigan, P.J., 1991). Muscle ailments are frequent occupational health problems. In the arm and shoulder, the most common condition is the oc cupational cervicobrachia l disorder (Gerr, Letz, and Landrigan, 1991), a painful conditi on of the neck and shoulder commonly seen in sedentary workers whose shoulders remain stationary but whose arms are involved in frequent fine-motor activity. Injuries to the nerves that operate the shoulder are uncommon but may occur in blunt trauma, lacerations, and motor vehicle accidents. Fractures and dislocations may also cause nerve trauma (Hannon, P., and Knapp, K. 2006, p. 236). Hand Injuries Occupational hand injuries may be classi fied into two categories: acute and chronic. The most common form of chronic in jury is overuse (repetitive motion disorder). These injuries include carpal tunnel s yndrome, tenosynovitis and other syndromes (Muggleton, J.M., Allen, R., and Chappell, P.H., 1999). Acute hand injuries include lacerations to the skin, nerves, and tendons; puncture wounds; thermal, chemical and electrical in juries; fractures; vascular injuries; and complex injuries, including avulsion (tea ring away), amputation and crush injuries. Lower Extremities The lower extremities include the thigh, knee, lower leg, ankle and foot (see Figure 225). The femur is the long bone of the le g and is connected by the hip joint to the

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73 pelvis and linked to the knee at the patella. Two bones, the tibia and the fibula, form the lower leg between the knee and the ankle. The knee is the jo int that connects the femur and the lower leg. Vulnerable structures of the knee, such as the patella, are often subjected to direct impact. A strong musculature surrounds the legs. The foot is adjoined to the lower leg. The foot c onsists of several bones. These include the tarsal bones and the phalanges (toes). Figure 225. Bones of the lower extremities ((Modified from ContMedia Human 3D Advanced Internet Edition, 2007). Types and Mechanisms of Injury Acute injuries to the upper and lower le g and knee may be caused by direct trauma, such as a blow or a motor vehicle accident Falls from a sufficient height can cause fractures to the long bones (femur, tibia and fibula). Chronic occupati onal leg injuries are related to the postural demands of specific jobs. Knee injuries are commonly a result of a direct blow to the knee. A heavy hammer might be used to strike objects in front of a worker who misses, result ing in a blow to the knee. Motor vehicle accidents account for mu ch of the direct trauma to the lower extremities. Another common mechanism of knee injury involves a twisting motion.

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74 Damage can occur to the ligaments and menisci. Injury occurs when the foot is fixed and the thigh turns. Within the construction indus try it is common for twisting to occur in situations in which the worker is attempting to escape an external force about to roll into the workers body. Chronic injury to the kn ee is a feature of oc cupations in which workers kneel or squat frequently. Construction workers at risk for chronic knee problems include, floor layers, carpet layers, stone cutters, tile setters, cement and concrete finishers, dry-wall-i nstallers and lathers, and car penters (Jensen, L.K. et al., 2000; Welch, L.S., et al., 1999; J; Tanaka, S. et al., 1989). The most common knee injuries are spra ins and meniscal tears (tears in the crescent-shaped cartilage of th e knee). Contusions (bruises), bursitis (inflammation of a burs, or sac) and chondromalacia patellae (softening of th e cartilage in the kneecap) account for the majority of the remainder (Jensen, L.K., and Eenberg, W., 1996). Fractures to the knee do occur but are unusua l. Patellar fractures may result from blunt trauma, as in a direct bl ow to the front of the knee. A fracture to the tibia at the knee may occur in a fall from a height (Goldsheyer, D. et al., 2004; Jensen, L.K., et al., 2000; Schneider, SP. 2001; Lipscomb, H.J., et al., 1997 ). Fractures of the femur can occur and are generally due to being struck by an obj ect moving with extreme force. Motor vehicle accidents and falls from heights account for the ma jority of these injuries (Islam, S.S. et al, 2001; Schneider, 2001). Lower extremity injuries in the workplace (o ther than those to the foot, ankle and knee) are uncommon. Leg and thigh injuries do occur; in addition to mild contusions (bruising). Such injuries range from burns to severe, open fractures.

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75 Burns can be classified into three types: thermal, chemical and electrical. There are several different mechanisms of sustaining thermal burns, including scalds, contact and flash burns. For the legs, the usual types of burns result from spills of a hot liquid (a scald) or chemical. Electrical injuries involving the leg us ually also affect the upper extremity and the rest of the body. Roofers, ro ad crews, and iron and steel workers are at higher risk for scalds (Horowitz, I.B., 2001; Islam, S.S., et al., 2000). Muscle injuries to the leg include cont usions, crushing injuries and ruptures. Contusions or bruises are generally caused by blunt trauma. Crushing in juries to the legs may result from material, equipment or vehicl es rolling on the legs. Crushing injuries can be life threatening. Leg muscle ruptures in the workplace usually involve the calf (Schneider, S.P., 2001). Ankle and Foot Occupational injuries to the foot and ankle are very prevalent within the construction industry (Schneider, S.P., 2001). R oofers, sheet metal workers, and machine repairers are typically at risk of such injuries (Hunting, K.L., 1999). The most common mechanism of foot injury is an object falling on or rolling over the foot, which may produce a contusion (bru ise), lacerations, crus hing injury, fracture or, very rarely, amputation. The most common a nkle injury is a spra in, usually resulting from twisting the ankle during a slip or fall. Blunt trauma may occur when the ankle is struck by a moving object (Oleske, D. M., Hahn, J.J.,and Leibold, M., 1992). Acute injuries to the foot and ankle usually result fr om obvious trauma. An object may fall on or roll over the foot, or strike th e ankle. The ankle may twist after a slip or fall. Chronic foot pain has been associated with factors that in clude footwear, floor surfaces, posture, body weight and congenital abnormalities.

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76 The vast majority of acute foot injuries result from objects being dropped onto the toes or the midfoot. In mild cases, there are only contusions. In more severe cases, there may be skin lacerations or fractures. Fractures of the foot are frequently multiple, due to the close proximity of the bones of the foot Lacerations and other skin wounds include puncture wounds, high pressure injection wounds and degloving injuries. Puncture wounds result most commonly when a worker steps on a sharp object. High pressure injection injuries are associated with the use of tools such as pressure washers, paint and grease guns (Oleske, D.M., Hahn, J.J. and Leib old, M., 1992). De-gloving injuries to the foot occur when the foot is trapped and subj ected to forces that shear off the skin and other tissue. Crushing injuries are most frequently cau sed by blunt trauma. The foot may be run over by a motor vehicle or other heavy equipm ent, or stuck by a falling object. Fractures are common in crushing injuries. Such fractures are usually multiple. Burns to the foot and ankle may result from scalding, chemical exposure or electrical contact. Scalds to the foot and ankle can occur w ith molten metals, bitumen and molten plastic. Roofers, road crews and felte rs are some of the workers likely to be affected. Contact burns have been reporte d by welders, caused by hot metal fragments falling inside their footwear (Horwitz, I.B., and McCall, B.P., 2005; Islam, S.S., et al., 2000). Chemical burns to the foot and a nkle, though uncommon in the construction industry, do occur and are usually associated w ith acidic or alkaline spills onto clothing or into footwear. Concrete workers may be at risk for such injuries (Lewis, P.M. et al. 2004). Electrical burns to the f oot almost always involve a high-voltage electrical injury. In such injuries, the hand is usually the site of entry and the foot is the exit site. Wounds

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77 created by current entry usually resemble a burn, whereas the ti ssue at the exit looks as if it exploded (Cawley, J.C., and Homce, G.T., 2003). Foot fractures usually involve the toes. Fractures of the long bones of the foot (metatarsals) are most often associated with direct blows, as in crushing injuries. Fractures of the heel bone ar e rare but frequently highly disabling. The usual mechanism is a fall from a height onto one or both feet, producing a crushing inju ry to the heel bone. Most commonly, the worker falls from scaffold ing or a ladder (Huang, X. and Hinze, J., 2003; Gillen, M., F., Beaumont, J.J., and McLoughlin, E., 1997). Ankle fractures commonly result from an inversion injury, in which the foot is forcibly tilted inward, causing damage to the lateral ligaments. The mechanisms are similar to that causing sprains but of greater force. Sprains are the most common ankle injury usually resulting from a fall onto th e twisted foot. A sprain is the twisting or straining of a joint so that some of the ligamen ts and other structures are torn or distorted but the bones remain in place. The majority of sprains to the ankle result from slips and trips (Schneider, S.P., 2001; Lipscomb, H.J. et al., 1997). Slips tend to occur when the floor surface changes unexpect edly and becomes wet or oil y. Trips occur when there is an unexpected object in the workers path.

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78 CHAPTER 3 METHODOLOGY The focus of this investigation was twofold; first, to examine the frequency of injuries experienced by construction work ers relative to several demographic and occupational factors, and second, to explore possible relationships between the severity of injuries to construction workers and several demographi c and occupational factors. The research was based on workers comp ensation data records provided by a large private insurance company. The data provi ded information on th e nature of the construction injuries, along with demographic information. The data were well suited to satisfy the objectives of my study. The use of insurance claims data can be especially valuable for population based studies and ar e particularly well suited for occupational injury surveillance st udies (Connell, F., Diehr, P. and Hart, L.G., 1987). This insurance provider maintains a proprietary information management system that contains patient demographic and injury data, as well as outpatient treatment, diagnostic, and billing information. For my study, only claims from individuals working in the construction industry (N = 46,056) from 1992 through January 2006 were analyzed. For each of the 46,056 claims, considerable information was provided regarding the following non-continuous (nominal), and c ontinuous (ordinal and scalar) variables: Non-Continuous o Nominal variables Gender Marital status Month of injury Day of the week General body region Body part General nature of injury Nature of injury General cause of injury Cause of injury

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79 General agent of injury Agent of injury Occupational work area Occupational experience level Continuous o Ordinal variables Age category Injury type (converted to injury severity scale) Job tenure category o Scalar variable Number of dependents Year of injury Age The information that was not utilized pert ained to the monetary costs of injuries. Some information, such as race and other s ensitive data were not made available for this research. Job tenure was generated by cal culating the number of days between the date of hire of the injured worker and the date of injury occurrence. The data set included information on workers Occupational work ar ea (the type of work being performed by the worker at the time of the injury), Nature of injury, specific Body part affected, Injury type (converted to injury severity score), Cause of injury, Agent of injury, and, and SIC classification. The nature of injury or illness describe s the principal physical characteristics of the injury or illness. Examples of nature of injury include amputation, burn, contusion, etc. APPENDIX A lists all of the nature of in jury codes utilized and the respective labels and descriptions for each code. Body Part identifies the part of th e body directly affected by the injury. Examples of the Body Part affected by the injury include brain, skull, arm, finger, shoulder, toes, etc. APPENDIX B lists all of th e labels and definitions used to code the part of the body variable. A General Body Region code was then generated by

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80 assigning specific body parts affect ed, as listed in APPENDIX B, to their respective body region as described within the USDOL-BLS Occupational Injury and Illness Classification Manual (1992). From this point on the General Body Region shall be referred to as Body Region The body re gion division was organized as follows Head: this region includes the uppermost pa rts of the body. This region consists of the skull, its contents, and related external structures. Neck: this division classifies that portion of the body that conn ects the head to the torso or trunk. This region is bounded by th e jaw/chin and cranial region at the top and the shoulder at the bottom. Upper extremities: this division classifi es the extremities that are bounded by the shoulder at the top with the fingers as th e lowermost part. This includes bones, cartilage, muscles, skin, subcutan eous tissue, veins and arteries. Trunk: this division cl assifies the main part of the body, to which the head and limbs are attached. The area is bounded by the neck, arms, and legs. This includes bones, cartilage, internal organs and structures, muscles, nerves, skin, subcutaneous tissue, tendons, veins a nd arteries, and internal organs and structures. Lower extremities: this divi sion classifies the appendages that are bounded by the hip at the top with the toes as the lowermost part. This includes bones, cartilage, muscles, skin, subcutaneous tissue, veins and arteries. Multiple body parts or body systems: this division classifies multiple body parts from two or more of the aforementioned di visions. This divisi on also contains the various systems of the body. This code al so applies when the functioning of an entire body system has been affected without specific injury to any other part of the body. The original data set provided information regarding the relative severity of the injuries through information given in an Injury Type field. The system for the classification of an injury complied with National Counsel on Compensation Insurance (NCCI) classification system. Based on paym ents made to claimants by the insuring agent, injuries were assigned to one of the following eight classifications:

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81 Death Permanent total disability: this is a condition where the injured party is not able to work at any gainful employment for the remaining lifetime. Permanent partial disability: this is a condition where the injured workers earning capacity is impaired for life, but the worker is able to work at reduced efficiency. Wage-loss and no impairment benefit: this is where wage loss benefits are paid and no impairment benefit is paid or payable. This includes compensation for temporary disability. Wage-loss and impairment benefit: this is where both wages loss benefits and impairment benefits are paid. Includes comp ensation for temporary disability. Temporary injury (temporary total or tempor ary partial benefits): this is a condition where the injured worker is unable to work at all while recovering from the injury, but that worker is expected to recover. Medical only: this is any injury that resu lted only in payment of medical expenses, without any compensable time lost from work. Contract medical: this is a c ontracted medical only cost whic h cannot be allocated to an individual claim. Each of these classifications was subsequent ly assigned an Injury Severity Score value from one to five, with five being the most severe injury (i.e., death). Pe rmanent total disabilities and permanent partial disabilities were assigned in jury severity score values of four and three, respectively. Following consultation with a repres entative from the private insurer, the provider of the claims data, it was decided to collapse or combine the two wage-loss classifications along with the temporary injury classification into a single group titled Temporary Injury. This classification was assigned an injury severity score value of two. Similarly, Medical Only and Contract Medical classifications were truncated into a single classification titled Medical Only. Medical only injuries rece ived the lowest injury severity score of one. The resulting five levels of Injury Severity are listed below. These scores were used to describe the relative severity level of injury.

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82 Medical only Temporary injury Permanent partial disability Permanent total disability Death The Cause of injury variable indicates the identified cause of the injury. There were seventy-five possible causes (see Appendix C) that could be assigne d to an injury. Each of these specific causes of injury was subsequently assign ed to one of the following eight General Cause of injury categories. Burned or scalded from exposure to heat or cold. Caught in or in-between. Injured by a cut, puncture or scrape. Injured by a fall or slip. Injury involving a motor vehicle (includes mo torized cars, snowmobiles, forklifts, etc.) Injured by straining. Injured by striking against or stepping on an object. Injured by being struck by an object. The Agent of Injury variable indicates the ma terial, hazard or object that directly caused or contributed to the injury or illness. Speci fic injuries were assigned to one of 113 possible Agent of Injury classifications APPENDIX D provides a list of the specific Agent of Injury classifications. An additional variable was generated from the agent of injury classifications to establish a broader General Agent of Injury va riable. The 21 categories for General Agent of Injury are also list ed in APPENDIX D. Only those workers classified within the USDOL Standard Industrial Classification (SIC) system as working within the construction industry (D ivision C) included in my study. Division C includes establishments primarily engaged in construction. The term c onstruction includes new work, additions, alterations, rec onstruction, installations, and repa irs. Construction activities are generally administered or managed from a relati vely fixed place of business, but the actual construction work may be performed at one or more different sites.

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83 The variable Major SIC Group was generate d to identify the three broad types of construction activities covered in Division C. See APPENDIX E for detailed descriptions for each of the categories. Code = 15 was buildin g construction by genera l contractors or by operative builders. Code = 16 was heavy construc tion other than building by general contractors and special trade contractors; and Code = 17 was construction activity by other special trade contractors. Building construction general c ontractors and operative build ers (code = 15): this major group includes general contractors and opera tive builders primarily engaged in the construction of residential, farm, industrial, commercial, or other buildings. Examples include the following: o General contractors-single -family houses (code = 1521) o General contractors-residen tial buildings, other than single-family (code = 1522) o Operative buildings (code = 1531) o General contractors-industrial bu ildings and warehouses (code = 1541) o General contractors-nonresidential buildings other than indust rial buildings and warehouses (code = 1542) o Sic code: building construction general contactors not elsewhere classified (code = 1543) Heavy construction other than building constr uction contractors (code = 16): this major group includes general contractors primarily engaged in heavy construction other than building, such as highways and streets, bridges, sewers, ra ilroads, irrigation projects, flood control projects and mari ne construction, and special trade contractors primarily engaged in activities of a type that are clea rly specialized for such heavy construction and are not normally performed on buildings or building-related projects. Examples include the following: o Highway and street construction, exce pt elevated highways (code = 1611) o Heavy construction, except highw ay and street (code = 1612) Construction special trade contractors (code = 17): this ma jor group includes special trade contractors who undertake activit ies of a type that are speci alized either to building construction, including work on mobile homes, or to both building and nonbuilding projects. These activities incl ude painting (including bridge painting and traffic lane painting), electrical work (including work on bridges, power lines, and power plants), carpentry work, plumbing, heating, air-c onditioning, roofing, and sheet metal work. Special trade contractors may work under s ubcontract with the general contractor, performing only part of the work covered by the general contract, or they may work directly for the owner. Special trade contractors for the most part perform their work at the site of construction, alt hough they also may have shops where they perform work

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84 incidental to the job site (prefabri cation). Examples include the following: o Plumbing, heating and air-c onditioning (code = 1711) o Painting and paper hanging (code = 1721) o Electrical work (code = 1731) o Masonry, stonework, tile setti ng, and plastering (code = 1740) o Masonry, stone setting, and ot her stone work (code = 1741) o Plastering, drywall, acoustical, a nd insulation work (code = 1742) o Terrazzo, tile, marble, and mosaic work (code = 1743) o Carpentry and floor work (code = 1741) o Carpentry work (code = 1751) o Floor laying and other floor work not elsewhere classified (code = 1752) o Roofing, siding, and sheet metal work (code = 1761) o Concrete work (code = 1771) o Water well drilling (code = 1781) o Miscellaneous special trad e contractors (code = 1790) o Structural steel er ection (code = 1791) o Glass and glazing work (code = 1793) o Excavation work (code = 1794) o Wrecking and demolition work (code = 1795) o Installation or erection of building equipment not elsewhere classified (code = 1796) o Special trade contractors not el sewhere classified (code = 1799) Special trade contractors are primarily enga ged in specialized c onstruction activities, such as plumbing, painting, and electrical wo rk, and work for general contractors under subcontract or directly for prope rty owners. General contractors us ually assume responsibility for an entire construction project, but may subcontra ct to others some or all of the actual construction work or those portions of the projec t that require special skills or equipment. General contractors thus may or may not ha ve construction workers on their payroll. Information was provided on the trades or occupations of the injured workers. The occupation coding structure was adapted from the National Council on Compensation Insurances (NCCI) SCOPES Manu al of Basic Classifications (2007). The original data set provided each claimants Regular Occupation Activity in conf ormance with the NCCI Scopes system. Examples include carpentry, door insta llation, concrete or cemen t work, concrete precast wall panel installation, asbestos contractor, sign installation, fi re suppression systems

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85 installation or repair, etc. Information provide d in the data set regarding the SIC and NCCI classifications was used to gene rate an Occupational work area variable, with 95 associated classifications (see APPENDIX EI) which attempted to indicate the specific occupational activity being performe d at the time of injury occurrence. In an attempt to reflect the workers experien ce levels within their particular occupational areas the variable Experience Le vel was generated by extrapolat ing the experience level (e.g., laborer, helper, apprentice, journeyman, etc.) from information provided in the original data set. The following ten categories were applied to this variable: Worker this was used when no specific e xperience level could be determined. This level was excluded from analysis when comp aring measures relative to the injured workers occupational experience level. Laborer this indicated workers who assist ed other construction workers to build or repair buildings, roads, bridges, dams, and other construction projec ts, and perform other unskilled tasks at construction sites. Helper/assistant this included workers in occupations concerned with helping more skilled workers in the construction trades. Apprentice include workers who are lear ning the craft or trade through on-the-job training and a formal appren ticeship training program. Journeyman this included any craft workers who have completed an apprenticeship program. Foreman this included any worker who is in charge of a construction crew. Generally a construction worker with many y ears of experience and talent. The foreman is a wealth of knowledge and a key asset to the project. Field supervision this included assistant su perintendents, superi ntendents, assistant project managers and project managers. Executive this included company representati ves at an executive management level (ceo, cfo, v.p., president, etc.) Professional this included any engineers, architects, designers, etc. Administrative this included all clerical workers, administ rative, and support personnel

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86 assigned to a particular construction project. Statistical Analysis The statistical analysis of the data were conduc ted at two levels; (1) the entire data set of injuries was examined for the injury distri bution by basic variables (age, age group, gender, general nature of injury, nature of injury, general cause of injur y, general agent of injury, agent of injury, job tenure on date of in jury, year of injury, month of in jury, day of the week of injury, occupational work areas, and occupational experien ce levels), and (2) an analysis of injuries specific to Body Region (Head, Neck, Truck, U pper Extremities, and Lower Extremities). In this analysis, all data were examined and evaluated by injury distributions. Means comparisons were performed for the continuous variables of age and injury severity. For two independent groups of subjects (such as gender, and new hires and non-new hires) the independent t-test was performed to determine whether the groups came from populations with the same mean for the variables of interest (age or inju ry severity) (Norusis, M.J., 2005). Figure 31 shows the protocol for mu ltiple comparisons of age and injury severity means; analysis of variance (ANOVA) or the Welc h robust test was used to assess equality of means. Subsequently, the Tukeys b range test, was utilized for a pair-wise multiple comparison of means (Aspelmeier, 2002). Th e decision to conduct either an ANOVA or the Welch test was made based on the results of the Levene test for equality of variances (age or injury severity scores) between the classifications of a given vari able (Aspelmeier, 2002). A ll statistical analysis was performed using SPSS for Windows Graduate Pack 13.0. Age and injury frequency and relative frequenc y distributions were generated for all the variables of interest. Fo r example, in Table 31 the injury frequencies and re lative frequencies are displayed for eight Experience Level ca tegories. All groups were ranked according to descending frequency magnitudes.

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87 Figure 31. Protocol for statistical multiple comparison of means (Aspelmeier, 2002).

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88 Table 31. Experience level of injured workers. Occupational experience level Numb er of injuries % Cumulative % Laborer 7,917 55.04%55.04% Apprentice 1,578 10.97%66.01% Foreman 1,449 10.07%76.09% Journeyman 1,358 9.44%85.53% Helper / assistant 752 5.23%90.76% Field supervision 614 4.27%95.02% Administrative 448 3.11%98.14% Professional 267 1.86%100.00% Total 14,383 100.00% Comparisons of injury severity means we re conducted by the following variables of interest: Age group Body part injured General nature of injury Nature of injury General cause of injury Cause of injury General agent of injury Occupational experience leve l of the injured worker Occupational work area of the injured worker Month of occurrence of the injury Day of week of occurrence of the injury For binary variables (such as gender) an i ndependent t-test was conducted to compare means. For multiple comparisons of means the Tukeys b range test (a.k.a., Tukeys Wholly Significant Difference test) was conducted to iden tify homogeneous subsets of means that were not different from each other, at p 0.05. For example, the ranking of the occupational experience levels by their respective injury severity means are shown in Figure 32. The T ukeys b test also identifies homogeneous subsets of means that were not significantly different from each other, at p 0.05 (indicated by vertical transparent boxes in Figure 32). Thus, the figur e shows that the injury severity means for the first seven categories of occ upational experience level were not significantly different at p

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89 0.05. From the arrangement of the homogeneous subsets, specific mean differences between groups were inferred. For example, the arrangeme nt of the homogeneous subsets in Figure 32were used to subsequently generate Figure 33 which shows that Journeyman level workers had a significantly greater injury severity mean, at p 0.05, than that for A dministrative level workers. 1.26 (.63) 1.30 (.56) 1.30 (.61) 1.31 (.57) 1.31 (.57) 1.35 (.59) 1.35 (.61) 1.39 (.62)1.151.201.251.301.351.40Administrative (n = 442) Helper/assistant (n = 738) Field supervision (n = 603) Apprentice (n = 1567) Professional (n = 265) Laborer (n = 7839) Foreman (n = 1434) Journeyman (n = 1350)Injury Severity Mean (Standard Deviation) Figure 32. Comparison of injury severity means by occupational experience levels. 1.39 (.62) 1.35 (.61) 1.35 (.59) 1.31 (.57) 1.31 (.57) 1.30 (.61) 1.30 (.56) 1.26 (.63)1.151.201.251.301.351.40Administrative (n = 442) Helper/assistant (n = 738) Field supervision (n = 603) Apprentice (n = 1567) Professional (n = 265) Laborer (n = 7839) Foreman (n = 1434) Journeyman (n = 1350)Injury Severity Mean (Standard Deviation) Figure 33. Differences of injury severi ty means by occupational experience levels. Prior to the use of the Tukeys b range test to rank groups by their means and identify homogeneous subsets of means, either an ANOVA test or Welch robust test for equality of means was conducted to determine if signi ficant differences between groups, at p 0.05, existed. Whether to use the ANOVA or the Welch test wa s predicated upon the outcome of the Levene

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90 test of homogeneity of age or in jury severity score variances be tween groups. If the significance of Levene test statistic (L) was greater than 0.05, equal variances were assumed and the ANOVA was performed. If the significance for L was less than or equal to 0.05, equal variances were not assumed and the Welch test was conducted. Figure 31 shows the decision protocol for the statistical multiple comparisons of means (Aspelmeier, 2002). Following the analysis of the broad scope of all the variables, further analysis was conducted focusing on injuries to the six B ody Regions (Head, Neck, Upper Extremities, Trunk, Lower Extremities and Multiple Body Parts or Body Systems). Injury distributions were generated for each of the individual variables with respect to each of the six Body Regions. For all of the ordinal and scalar measures, additional Welch tests or ANOVA test and multiple comparisons of means tests, as described a bove, were conducted to fu rther explore possible significant relationships be tween variables specific to the Body Regions.

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91 CHAPTER 4 RESULTS A large private insurance company (workers compensation carrier) provided information on 46,016 construction worker injuries that o ccurred between 1992 and 2006. The identities of the injured workers were not prov ided so some workers may have appeared more than once in the dataset, i.e., workers who might have been in jured more than once could not be identified. In my study, each claim or injury was counted as a se parate injury case, and the entire dataset was referred to as representing ,056 injured workers. Each injury case was accompanied by several descriptors related to the injured worker and the injury that wa s sustained. The injury severity was the primary dependent variable for this dataset. Frequenc y distributions, relative frequency (%) and percentage cumulative frequency were generated for the injuries for all of the categories with respect to each of the variable s. A tabular arrangement of these data was prepared. For binomial variables (e.g. gender, new hires or non-new hires) an independent t-test was conducted to determine possible differences between the average injury se verity between the two groups. Each injury was assigned an injury sever ity score ranging from one with one being the lowest severity ascertained and five being death. The actual severity descriptions associated with each score was as follows; 1. Medical only 2. Temporary injury 3. Permanent partial disability 4. Permanent total disability 5. Death An alpha level of p 0.05 was used for all statistical tests to assert statistically significant findings. A Levene test of homogeneity of variances of injury severity scores for the classifications for each examined variable was performed to decide whether to use the Welch

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92 robust test of equality of means or the Analysis of Variance (ANOVA) to compare the mean levels. If the Levene test (L) statistical significance was greate r than 0.05, equal variances were assumed, and the ANOVA test was conducted to ev aluate significant in jury severity mean differences between categories. If the Levene statistical significance was less than or equal to 0.05, equal variances was not assumed, and the Welch robust test of equality of means was conducted. The Welch statistic was used instead of the Brown-Fors ythe statistic because it was considered to be more powerful and mo re conservative (Norusis, M., 2000, p. 152). When the injury severity scor e variance of one or more of the categories being compared was zero, then the Welch test could not be c onducted. In this situa tion, the ANOVA test was used in lieu of the Welch test. If the test statistic of either the ANOVA or the Welch test was significant at or below the desired alpha (p) of 0.05, then at least one category had a significantly different injury severity mean of another catego ry within the variable. After it was determined that differences existed among the means, the Tukeys Wholly Significant Difference (Tukeys b) post hoc range test was used to determine whic h means differed. The Tukeys b range test also identified homogeneous subsets of means th at were not different of each other at p = 0.05. The Tukeys b test also generated a ranking of categor ies according to their descending magnitude of mean values. Because of the ranking capabilities of the Tukeys b and th e tests potential to identify possible differences between groups contra ry to the results of either the Welch or the ANOVA tests, the Tukeys b was still run after the results of the Welch or ANOVA indicated no significant differences, at p 0.05, between variable groups. Simila r tests were often run to also examine the variable associations with age.

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93 Demographic Characteristics Gender Gender designation was provided for 44,743 of the injury cases. Over 95% of the injured workers were male (see Table 41). The effect of gender on injury severity was not statistically significant, F = (1, 44,117) = .74, p > .30. Table 41. Gender of injured workers. Gender Number of injuries % Cumulative % Male 42,84195.75% 95.75% Female 1,9024.25% 100.00% Total 44,743100.00% The variable General Occupational Experi ence provided information on the experience level of workers, and this was examined in re lation to education, training, and apprenticeship /internship experience prior to the event leadi ng to the injury. The re lationship between gender and General Occupational Experience was exam ined for 14,125 worker injuries. Table 42 displays the distribution, by per centage, of workers within thei r respective gender categories by the General Occupational Experience levels. Over 50% of both male and female workers were classified as laborers. Over 11% of the male (n = 1,475) and 10% of the female (n = 81) workers were at the apprentice level. The relative frequency (10.50%) of injuries among male foremen (n = 1,401) exceeded the frequency (2.81%) of female foremen, (n = 22). Similarly, there was a higher relative frequency (9.87%) among male journeymen, (n = 1,317) than among female journeymen, 3.07% (n = 24). For both male and fema le workers the relative frequency of helper or assistant level workers was virtually 5%. Th e percentage of field supervisors among males (4.44%, n = 593) exceeded that for female superv isors (1.53%, n = 12). For the administrative and professional levels, the relative frequenc ies among females, 15.45% (n = 121) and 3.58% (n = 28), respectively, exceeded that of ma les, 2.36% (n = 315) and 1.76% (n = 235).

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94 Table 42. Comparison of injury frequencie s between males and females by occupational experience level. Male Female General occupational experience level Number of injuries % Cumulative % Number of injuries % Cumulative % Laborer 7,310 54.79% 54.79%45457.98% 57.98% Apprentice 1,475 11.06% 65.85%8110.34% 68.32% Foreman 1,401 10.50% 76.35%222.81% 71.13% Journeyman 1,317 9.87% 86.22%243.07% 74.20% Helper/assistant 696 5.22% 91.43%415.24% 79.44% Field supervision 593 4.44% 95.88%121.53% 80.97% Administrative 315 2.36% 98.24%12115.45% 96.42% Professional 235 1.76% 100.00%283.58% 100.00% Total 13,342 100.00% 783100.00% The distribution of injury frequencies and relative frequencies for Nature of Injury categories for male and female workers are shown in Table 43 and Table 44. For both male (n = 11,131) and female (n = 563) worker s, strain injuries had the hi ghest relative frequency of all the Nature of Injury classifica tions. The top ten Nature of In jury categories, in terms of relative frequency of injuries, were the same for both males and females. However, their respective order by magnitude differs. For male s the top ten Nature of Injury groups by relative frequency were as follow: 1. Strains, 28.66% (n = 11,131,) 2. Lacerations, 16.62% (n = 6,456) 3. Contusions, 13.90% (n = 5,397) 4. Foreign body, 9.44% (n = 3,666) 5. Sprain, 6.05%, (n = 2,350) 6. Fracture, 5.97% (n = 2,317) 7. Puncture, 5.04% (n = 1,956) 8. Inflammation, 2.54%, (n = 986) 9. Burn, 2.16% (n = 839) 10. Multiple Injuries, 1.63% (n = 635) For female workers the top ten Nature of In jury classifications by relative frequency were as follows:

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95 1. Strains, 33.85% (n = 563) 2. Contusions, 19.60% (n = 326) 3. Lacerations, 9.32% (n = 155) 4. Sprains, 7.46% (n = 124) 5. Foreign body, 6.37% (n = 106) 6. Fractures, 5.41% (n = 90) 7. Inflammation, 3.97% (n = 66) 8. Punctures, 2.59% (n = 43) 9. Multiple Injuries, 1.80% (n = 30) 10. Burns, 1.56% (n = 26) These top ten groups account for over 91% of a ll the injuries reported for both the male and female workers. For female workers, resp iratory disorders (n = 19) and carpal tunnel syndrome (n = 18) each accounted for just over 1% of all the reported injuries. For male workers, respiratory injuries represente d less than 0.05% (n = 164) and car pal tunnel syndrome less than 0.20% (n = 78) of all the reported injuries for the Nature of Inju ry classifications. Myocardial infarctions showed the highest ov erall injury severity mean, with a higher relative frequency for males, 0.12% (n = 45) than for females, 0.06% (n = 1). Over 25% of the male injuries(n = 11,493) and over 30% of the female injuries (n = 545) were caused by straining while performing some t ype of task or motion (see Table 45 and Table 46). Just over 16% (n = 6,601) of the male and 23% (n = 413) of the female injuries were caused by a fall or slip. Around 14% (n = 5,654) of the injuries of males and 11% (n = 203) of the injuries to females resulted of being struck by an object or person. Being cut, punctured or scraped by an object accounted for almost 13% (n = 5,283) of the in juries to male workers and 7% of the injuries to female workers (n = 117) Almost ten % of the injuries of males were attributed to foreign matter in the eyes (n = 9.52 %), while foreign matter in the eyes accounted

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96 Table 43. Injuries to males by nature of injury. Male workers Nature of injury Number of injuries % Cumulative % Strain 11,13128.66%28.66% Laceration 6,45616.62%45.28% Contusion 5,39713.90%59.18% Foreign body 3,6669.44%68.62% Sprain 2,3506.05%74.67% Fracture 2,3175.97%80.63% Puncture 1,9565.04%85.67% Inflammation 9862.54%88.21% Burn 8392.16%90.37% Multiple injuries 6351.63%92.01% Crushing 4411.14%93.14% Rupture 4331.11%94.26% Hernia 3750.97%95.22% Infection 2060.53%95.75% Dislocation 1930.50%96.25% Asbestosis 1720.44%96.69% Respiratory disorder 1640.42%97.11% Dermatitis 1370.35%97.47% Electric shock 1160.30%97.77% Heat prostration 1100.28%98.05% Occupational disease NOC 1010.26%98.31% Amputation 850.22%98.53% Chemical poisoning 850.22%98.75% Carpal tunnel sryndrome 780.20%98.95% Concussion 730.19%99.13% Severance 660.17%99.30% Poisoning NOC 550.14%99.45% Hearing loss or impairment 510.13%99.58% Myocardial infarction 450.12%99.69% Enucleation 290.07%99.77% Mental stress/disorder 290.07%99.84% Syncope 190.05%99.89% Asphyxiation 180.05%99.94% Angina pectoris 90.02%99.96% Silicosis 80.02%99.98% Freezing 70.02%100.00% Total 38,838100.00%

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97 Tabel 44. Injuries to fe males by nature of injury. Female workers Nature of injury Number of injuries % Cumulative % Strain 56333.85%33.85% Contusion 32619.60%53.45% Laceration 1559.32%62.77% Sprain 1247.46%70.23% Foreign body 1066.37%76.60% Fracture 905.41%82.02% Inflammation 663.97%85.98% Puncture 432.59%88.57% Multiple Injuries 301.80%90.37% Burn 261.56%91.94% Respiratory disorder 191.14%93.08% Carpal tunnel sydrome 181.08%94.16% Rupture 140.84%95.00% Dermatitis 120.72%95.73% Crushing 90.54%96.27% Dislocation 90.54%96.81% Heat prostration 90.54%97.35% Occupational disease NOC 80.48%97.83% Infection 50.30%98.13% Chemical poisoning 50.30%98.43% Electric shock 40.24%98.67% Hernia 40.24%98.91% Asbestosis 30.18%99.09% Mental stress/disorder 30.18%99.27% Concussion 20.12%99.39% Hearing loss or impairment 20.12%99.51% General poinoning 20.12%99.63% Amputation 10.06%99.69% Enucleation 10.06%99.75% Freezing 10.06%99.82% Myocardial infarction 10.06%99.88% Severance 10.06%99.94% Asphyxiation 10.06%100.00% Toal 1,663100.00%

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98 Table 45. Injuries to males by general cause of injury General cause of injury Number of injuries % Cumulative % Strain 11,49328.25% 28.25% Fall or slip 6,60116.22% 44.47% Struck by 5,65413.90% 58.37% Cut, puncture, or scrape 5,28312.98% 71.35% Foreign matter 3,8749.52% 80.87% Striling against or stepping on 2,7146.67% 87.55% Caught in or between 2,2275.47% 93.02% Absorption, ingestion or inhalation 1,0822.66% 95.68% Burn or Scalded By 8872.18% 97.86% Contact with An Organism 4951.22% 99.07% Motor vehicle 3780.93% 100.00% Total 40,688100.00% Table 46. Injuries to female s by general cause of injury. General nature of injury Number of injuries % Cumulative % Strain 54530.60% 30.60% Fell or slipped 41323.19% 53.79% Struck or injured by 20311.40% 65.19% Striling against or stepping on 1327.41% 72.60% Foreign matter 1206.74% 79.34% Cut, puncture, or scrape by 1176.57% 85.91% Caught in or between 744.15% 90.06% Absorption, ingestion or inhalation 734.10% 94.16% Contact with an organism 472.64% 96.80% Burn or scalded by 351.97% 98.76% Motor vehicle 221.24% 100.00% Total 1,781100.00% for less than 7% of the injuries of females. Striking against or stepping on an object (males = 2,714; females = 132) combined with being Caught in or between an object or objects (males = 2,227; females = 74) resulted in over 12% of the inju ries to male workers and just over 11% of the injuries to female workers. Absorption, inha lation or ingestion of a substance (males = 1,082; females = 73), being burned or scalded by contac t with an object or substance (males = 887; females = 35), contact with an organism (males = 495; females = 47) an d activities involving a

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99 motor vehicle (males = 378; females = 22) combined to account for less than 7% of the injuries to males and over 10% of the injuries to females. The distribution of injury se verity means for the six Body Region categories by gender is displayed in Table 47. Information on thes e variables was provided for 44,069 workers. Over 16% of the male injuries (n = 6,970) and over 12% of the female injuries (n = 238) were head injuries. Injuries to the neck acc ounted for slightly over 2% of all the injuries to males (n = 885) and almost 3% of the injuries to females (n = 506). Almost 30% of the males (n = 12,118) experienced injuries to the upper extremities wh ile 27% of the females (n = 506) sustained injuries to the upper extremities. Trunk injuries accounted for approximately 25% of both the male injuries (n = 10,765), and the female injuries (n =506). Lower extremities accounted for over 22% (n = 415) of the female injuries and ov er 20% (n = 8,485) of the male injuries. Females sustained a higher relative fre quency of multiple body part or body systems injuries, 10.75% (n = 201) versus 7.05% (n = 2,977) for male workers The injury severity means associated with each of the Body region categories for male and female workers are shown in Table 47. An analysis of variance was conducted to compare, between male and females workers, the injury severity means for each of the Body region classifications. The results showed that injury severity was not significantly different, at p 0.05, on the basis of gender with re spect to all of the Body Regi on groups (see Table 48). Differences between injury severity means of the six Body Region categories were also explored further by gender. The results of the Le vene test of homogeneity of variances of the injury severity scores by the Body Region cate gories for male workers did not allow for the assumption of equal variance, L (5, 42,194) = 1204.44, p < .001. The results of the subsequent

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100 Welch robust test of equality of injury severity means indicated that, am ong males, at least one of the Body Region categories had a significantly di fferent injury severity mean than one of Table 47. Comparison between males and fema les of injury severity means by body region. Body region Gender N % of gender group* Mean injury severity Male 697016.52%1.110.40 Head Female 23812.73%1.120.36 Male 8852.10%1.470.70 Neck Female 552.94%1.600.83 Male 1211828.72%1.260.54 Upper extremities Female 50627.07%1.270.52 Male 1076525.51%1.450.64 Trunk Female 45424.29%1.430.61 Male 848520.11%1.400.62 Lower extremities Female 41522.20%1.390.63 Male 29777.05%1.470.75 Multiple body parts/body systems (MBRBS) Female 20110.75%1.430.70 Males = 42,200; Females = 1,869 Table 48. ANOVA, comparison, by gender, of injury severity means by body region. Body region Sum of squares df Mean square F p* Between groups 0.0010.01 Within groups 1158.9672060.16 Head Total 1158.977207 0.040.84 Between groups 0.8310.83 Within groups 467.839380.50 Neck Total 468.65939 1.660.20 Between groups 0.0110.01 Within groups 3717.06126220.29 Upper extremities Total 3717.0712623 0.040.85 Between groups 0.0910.09 Within groups 4555.11112170.41 Trunk Total 4555.2011218 0.220.64 Between groups 0.0210.02 Within groups 3445.3588980.39 Lower extremities Total 3445.378899 0.050.82 Between groups 0.2510.25 Within groups 1760.7831760.55 Multiple body parts/body systems (MBRBS) Total 1761.033177 0.450.50 Significance assumed at p 0.05

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101 the other groups, F (5, 6,996.94) = 506.08, p < .001. This result was confirmed by the results of the Tukeys b range test for injury severity means, significant at p 0.05, for the Body Region categories. Figure 41 shows the distribution of injury severity means, in descending magnitudes, associated with each of the six Body Regi on categories for male workers. Homogenous groupings, indicated by the transpar ent boxes, indicated lack of si gnificant difference of injury severity means, at p 0.05, between the respective Body Regi on categories. The least severe injuries were head injuries which were less severe that upper extremity injuries and these were less severe than the lower extremity injuries. 1.47 (.70) 1.47 (.75) 1.45 (.64) 1.40 (.62) 1.26 (.54) 1.11 (.40) 0.000.200.400.600.801.001.201.401.60 Head (n = 6978) Upper extremities (n = 12128) Lower extremities (n = 8488) Trunk (n = 10780) Multiple body regions or body systems (n = 2979) Neck (n = 908) Males: Injury Severity Mean (Standard Deviation) Figure 41. Comparison of injury severity mean s by body region for injuries to male workers. Significant differences of injury severity means exist between specific body regions among male workers are illustrated in Figure 4. The homogeneous group of injuries to the neck ( = 1.47), m ultiple body parts or body systems ( = 1.47) and trunk ( = 1.45) had a significantly higher injury severity mean, at p 0.05, than for all of the rema ining Body Region categories. Injuries to the lower extremities had a significantly greater, at p 0.05, injury severity mean ( = 1.40) than injuries to the upper extremities ( = 1.26) Injuries to the head exhibited an injury

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102 severity mean ( = 1.11) significantly lower, at p 0.05, than all of the remaining Body Region categories. 1.47 (.70) 1.47 (.75) 1.45 (.64) 1.40 (.62) 1.26 (.54) 1.11 (.40) 0.000.200.400.600.801.001.201.401.60 Head (n = 6978) Upper extremities (n = 12128) Lower extremities (n = 8488) Trunk (n = 10780) Multiple body regions or body systems (n = 2979) Neck (n = 908) Males: Injury Severity Mean (Standard Deviation) Figure 42. Difference of injury severity mean s between body regions for injuries to male workers. For female workers, no assumption of equal variance of injury seve rity scores by Body Region category could be made, L (5, 1,863) = 48.44, p < .001. The results of the Welch robusf of equality of injury severity means by the body regions for females indicated that at least one of these regions had a significantly different injury severity m ean than one of the other body regions, F (5, 405.82) = 21.40, p < .001. This was confirmed by the results of the Tukeys b range test (see Figure 4 3). As shown in Figure 43, among female worker s, neck injuries had the highest injury severity mean ( = 1.60) followed by injuries to multiple body parts or body systems ( = 1.43), trunk ( = 1.43), lower extremities ( = 1.40), upper extremities ( = 1.27), and head injuries ( = 1.12). At p 0.05, the results of the Tukeys b range te st indicated that, among female workers, neck injuries exhibited a significan tly higher injury severity mean than injuries to the lower and upper extremities, and head injuries. Injuries to multiple body parts or body systems, the trunk

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103 region, and lower extremities each had a signifi cantly greater injury severity mean, at p 0.05, than injuries to the he ad (see Figure 44). 1.60 (.83) 1.43 (.70) 1.43 (.61) 1.40 (.63) 1.27 (.52) 1.12 (.36) 0.000.200.400.600.801.001.201.401.601.80Head (n = 239) Upper extremities (n = 506) Lower extremities (n = 415) Trunk (n = 455) Multiple body regions or body systems = 201) Neck (n = 58)Females: Injury Severity Mean (Standard Deviation) Figure 43. Comparison injury severity m eans by body region for female workers. 1.60 (.83) 1.43 (.70) 1.43 (.61) 1.40 (.63) 1.27 (.52) 1.12 (.36) 0.000.200.400.600.801.001.201.401.601.80 Head (n = 239) Upper extremities (n = 506) Lower extremities (n = 415) Trunk (n = 455) Multiple body regions or body systems = 201) Neck (n = 58) Females: Injury Severity Mean (Standard Deviation) Figure 44. Difference of injury severity mean s between body regions for female workers. Marital Status Information on marital status was provided for 30,762 construction worker workers. Table 49 shows the distribution of work er injuries for the five Marital Status classifications. Over 57% (n = 17,621) of the injured workers were married and over 38% (n = 11,825) were single.

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104 Divorced (n = 976), separated (n = 246) and widowed (n = 94) workers constituted less than 5% of the workers. Table 49. Injuries by marital status. Marital status Number of injuries % Cumulative % Married 17,621 57.28% 57.28% Single 11,825 38.44% 95.72% Divorced 976 3.17% 98.89% Separated 246 0.80% 99.69% Widowed 94 0.31% 100.00% Total 30,762 100.00% The Levene statistic was use to check for ho mogeneity of variances of injury severity scores for the five Marital Status categories. The results of this test did not allow for an assumption of equal variances, L (4, 30,513) = 4, p < .001. The subsequent Welch robust test of equality of means was conducted to explore possi ble differences between injury severity means of the different Marital Status groups. The results of this test indicated that at least one of the marital status classifications was associated with a significantly different injury severity mean of one of the other classifications, F (4, 504.96) = 6.87, p < .001. However, the results of the Tukeys b range test for injury severity mean s could not confirm any significant differences between the Marital Status groups, at p 0.05. Figure 45 ranks th e five Marital Status groups by descending magnitudes of injury severity mean. As the transparent box indicates, there were no significantly different, at p 0.05, injury severity means between any of the marital status classifications. 1.33 (.54) 1.36 (.61) 1.39 (.64) 1.40 (.75) 1.43 (.67) 1.261.281.301.321.341.361.381.401.421.44 Separated (n = 245) Single (n = 11731) Married (n = 17476) Widowed (n = 93) Divorced (n = 973) Injury Severity Mean (Standard Deviation) Figure 45. Comparison of injury severity means by marital status.

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105 Number of Dependents Information regarding the total number of dependents for each injured worker was provided in 11,446 cases. A fairly equivalent number of injure d workers reported having one dependent (30.6%, n = 3,500) or two dependents (30.0%, n = 3,438). Almost 80% of the injured workers (79.7%, n = 9,013) reported having one to three dependents. Less than 20% of the workers (17.7%, n = 2,027) had between four a nd six dependents. The remaining workers with dependents (3.5%, n = 406) claimed seven or more children. Injured workers who were married but for which the number of dependents was not given were initially assumed to have no dependents. The married workers with no depende nts had an injury severity mean of 1.38 ( = 0.63). By observation of the injury severity mean for married workers with no dependents, there is no difference of injury severity means for the number of dependents. Equal variances of injury severity scores c ould not be assumed for the three Number of Dependents groupings L (2, 11,365) = 25.18, p 0.05. The results of the Welch robust test of equality of means showed that a statistically significant di fference existed between these categories with respect to injury severity means, F (2, 1,01.34) = 10.49, p .001. The Tukeys b range test was conducted to rank the Number of Dependents categories according to their respective mean injury severity le vels. Figure 46 shows this dist ribution in descending order of injury severity. Boxed groupings show group mean s that are not signifi cantly different, at p 0.05, of each other. Despite the significant F value of the Welch test, no statistically significant difference, at p 0.05, was found between the Number of Dependents categories. Age Age was provided for 14,963 of the 46,056 cases. The mean age of injured workers was 37.71 years, with age ranging of 15 and 77 years. Ta ble 410 displays the distribution of all the injured workers by age. Workers within the 30 to 39 (n = 4,350), 20 to 29 (n = 3,900), and 40 to

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106 1.37 (.62) 1.38 (.63) 1.44 (.68) 1.321.341.361.381.401.421.441.46 4 to 6 (n = 2016) 7 or more (n = 400) 1 to 3 (n = 8952) Injury Severity Mean (Standard Deviation) Figure 46. Comparison of injury severity means by number of dependents. 49 (n = 3,893) age groups each comprised over 26% of the workers for whom age information was provided. Workers aged 50 through 59 years accounted for over 13% (n = 2,067) of these cases. Workers 60 years of age or older comprise d just over 3% (n = 452) of the cases. Workers under the age of 20 made up just over 2% (n = 301) of all the cases. A multiple comparison of mean ages was conducted for the General Occupational Experience categories. Equal variances of ages could not be assumed for the eight General Occupational Experience cat egories, L (7, 4,615) = 30.10, p 0.01. Subsequently, the Welch robust test of equality of means indicated that at least one of the General Occupational Experience categories had a significantly diffe rent mean age than another, F (7, 496.74) = 155.79, p .001. This result was confirmed by the re sults of the Tukeys b range test. Table 410. Injuries by age. Age group (years) Number of injuries % Cumulative % 30 39 4,35029.07% 29.07% 20 29 3,90026.06% 55.13% 40 49 3,89326.02% 81.15% 50 59 2,06713.81% 94.97% 60 69 4142.77% 97.73% Under 20 3012.01% 99.74% Over 69 380.25% 100.00% Total 14,963100.00% Figure 47, displays the results of the Tukeys b range test. Field supervisory level workers had the highest mean age of 45.33 years. Foremen ranked second according to age ( =

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107 42.37), followed by professionals ( = 41.07), jo urneymen ( = 40.67), administrative level workers ( = 39.97), laborers ( = 35.72), and helpers or assistan ts ( = 30.91). Apprentice level workers had the lowest mean age of 28.66 years. Supervisors, including superint endents and assistant superint endents, were significantly older, at p 0.05, than all other experience level categor ies (see Figure 48). Workers at the foreman level had a significantly higher, at p 0.05, mean age than did administrative workers, laborers, helpers or assistants, and apprentices. The mean ages of professionals, journeymen, and administrative level workers were significantly greater, at p 0.05, than that of laborers, helpers and assistants, and apprentices. Laborers had a significantly greater mean age, at p 0.05, than did helpers and assistants/apprentices. The severity of injury was examined with respect to the age of the injured workers. Workers whose date of hire was 30 days or less of the date of injury (e.g., New Hires) were excluded of initial consideration under the assumption that most new workers would be receiving safety training and orientation w ithin the first 30 days of hire. To avoid the confounding effect of the training, new hire s were excluded. 45.33 (10.14) 42.37 (9.55) 41.07 (12.44) 40.67 (9.79) 38.97 (12.64) 35.72 (11.36) 30.91 (10.10) 28.66 (8.34) 0.005.0010.0015.0020.0025.0030.0035.0040.0045.0050.00 Apprentice (n = 674) Helper/assistant (n = 255) Laborer (n = 2304) Administrator (n = 141) Journeyman (n = 532) Professional (n = 44) Foreman (n = 483) Field supervisor (n = 190) Mean Age (Standard Deviation) Figure 47. Comparison of mean ages by occupational experience level.

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108 45.33 (10.14) 42.37 (9.55) 41.07 (12.44) 40.67 (9.79) 38.97 (12.64) 35.72 (11.36) 30.91 (10.10) 28.66 (8.34) 0.005.0010.0015.0020.0025.0030.0035.0040.0045.0050.00 Apprentice (n = 674) Helper/assistant (n = 255) Laborer (n = 2304) Administrator (n = 141) Journeyman (n = 532) Professional (n = 44) Foreman (n = 483) Field supervisor (n = 190) Mean Age (Standard Deviation) Figure 48. Differences of mean ages between general occupational experience levels. The Levene statistic was conducted to check for homogeneity of injury severity scores for the seven age groupings for non-new hires. This statistic revealed that equal variance between the age groups could not be assumed, L (6, 9,412) = 80.31, p .001. The results of the Welch robust test of equality of means showed that at least one of the age groups had a significantly different injury severity mean of one or more of the other age groupings. F (6, 296.28) = 28.53, p .01. This was confirmed by the subsequent Tukeys b range test. Using the Tukeys b mean range test, a multiple comparison of injury severity means test was conducted with the Age Group variable for non-new hires. From Figure 49, it is observed that as non-new hires got older the seve rity of injury increased. Among non-new hires, workers over the age of 69 had th e highest injury severity mean ( = 1.85), followed by workers between the ages of 60 and 69 years ( = 1.55), workers of 50 to 59 years of age ( = 1.39), workers 40 to 49 years of age ( = 1.38), 30 to 39 years old ( = 1.32), and workers 20 to 29 years of age ( = 1.22). Workers under the age of 20 years had the lowest injury severity mean, equal to 1.30, among the non-new hire workers.

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109 1.85 (.92) 1.55 (.81) 1.39 (.64) 1.38 (.63) 1.32 (.60) 1.22 (.50) 1.20 (.44) 0.000.200.400.600.801.001.201.401.601.802.00 Under 20 (n = 166) 20 29 (n = 2452) 30 39 (n = 2713) 40 -49 (n = 2535) 50 59 (n = 1320) 60 69 (n = 275) Over 69 (n = 27) Injury Severity Mean (Standard Deviation) Figure 49. Comparison of injury severity means by age for non-new hires. From the homogeneous groupings of injury severity means shown in Figure 49, significant differences of injury severity means, at p 0.05, between specific age groups among non-new hires were determined (see Figure 410 ). It was observed that non-new hires who were over 69 years of age had a significantly higher injury severity mean, at p 0.05, than all of the other non-new hires. It was also observed that the workers between the age of 60 and 69 had a significantly higher injury severity mean, at p 0.05, than workers under the age of 40. A similar analysis was conducted to examine injury severity means by age for workers who had been employed by the current employer for le ss than 30 days at the da te of the injury. It was determined that equal variance c ould not be assumed, L (6, 2,376) = 24.36, p .01. The subsequent Welch robust test of equality of mean s showed that for these new employees at least one of age grouping had a significantly different injury severity mean of one or more of the other age groups, F (6, 108.31) = 8.72, p .001. This result was confirmed by the results of the Tukeys b range test.

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110 1.20 (.44) 1.22 (.50) 1.32 (.60) 1.38 (.63) 1.39 (.64) 1.55 (.81) 1.85 (.92) 0.000.200.400.600.801.001.201.401.601.802.00 Under 20 (n = 166) 20 29 (n = 2452) 30 39 (n = 2713) 40 -49 (n = 2535) 50 59 (n = 1320) 60 69 (n = 275) Over 69 (n = 27) Injury Severity Mean (Standard Deviation) Figure 410. Differences of injury severity means between age groups of non-new hires. The distribution of injury se verity means following a Tukeys b means range test are shown in Figure 4-. Workers over the age of 69 years ( = 1.60) had the highest inju ry severity mean among new hires. This was followed by inju ry severity means associated with new hires between the ages of 60 and 69 years of age ( = 1.51), 40 and 49 ( = 1.43), 50 and 59 ( = 1.43), new hires under 20 years of age ( = 1.35), and new hires between 30 and 39 years of age ( = 1.32). Workers between the ages of 20 and 29 y ears had the lowest injury severity mean ( = 1.23). From the homogeneous groupings of injury severity means shown in Figure 411, significant differences of injury severity means, at p 0.05, between specific age groups among the new hires were identified. It was observed th at new hires who were over 69 years of age had a significantly higher injury severity mean, at p 0.05, than new hires with ages between 20 and 29 years (see Figure 412).

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111 1.60 (.84) 1.51 (.68) 1.43 (.64) 1.43 (.67) 1.35 (.57) 1.32 (.55) 1.23 (.49)0.000.200.400.600.801.001.201.401.601.8020 29 (n = 668) 30 39 (n = 714) Under 20 (n = 82) 50 59 (n = 299) 40 -49 (n = 561) 60 69 (n = 49) Over 69 (n = 10)New Hires: Injury Severity Mean (Standard Deviation) Figure 411. Comparison of injury severity means by age of new hires. 1.60 (.84) 1.51 (.68) 1.43 (.64) 1.43 (.67) 1.35 (.57) 1.32 (.55) 1.23 (.49)0.000.501.001.502.0020 29 (n = 668) 30 39 (n = 714) Under 20 (n = 82) 50 59 (n = 299) 40 -49 (n = 561) 60 69 (n = 49) Over 69 (n = 10)New Hires: Injury Severity Mean (Standard Deviation) Figure 4-12. Differences of injury severi ty means between ages of new hires. An independent samples t-test showed that th ere was no statistically significant difference in injury severity means between new hires ( = 1.38) and workers who had been working for more than 30 days prior to bei ng injured ( = 1.3 6), t (34,177) = 1.79, p > 0.05 A similar investigation was conducted to compare injury severity means between new and non-new hires with respect to age. Figure 413 shows the m eans comparisons by age. The results showed that that new hires had significantly higher injury severity means th an did non-new hires within both the under 20 age group (t (242) = 2.45, p < 0.001) and the 40 to 49 y ears age group (t (3,081) = 1.93, p < 0.01) categories. There were no other st atistically significant differences, at p 0.05, for the remaining age groups. A change in the tr end among workers 60 years of age or older was displayed. The workers between the age of 60 a nd 69 and workers older than 69 years of age

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112 showed a reverse trend in which non new hires ha d a higher injury severity mean than did new hires. 1.35 (.57) 1.19 (.44) 1.23 (.40) 1.22 (.50) 1.32 (.55) 1.32 (.60) 1.43 (.64) 1.38 (.63) 1.43 (.67) 1.40 (.64) 1.51 (.68) 1.55 (.81) 1.60 (.84) 1.83 (.92) 0.000.200.400.600.801.001.201.401.601.802.00 (n = 82) (n = 162) (n = 82) (n = 2425) (n = 714) (n = 2697) (n = 561)) (n = 2522) (n = 299)) (n = 1315) (n = 49) (n = 274) (n = 10) (n = 24) Under 20 (t = 2.45; df = 242; p .05)20 2930 39 40 -49 (t = 1.93; df = 3081; p .05)50 5960 69Over 69 Injury Severity Means (Standard Deviation) > 30 Days New Hires Figure 413. Differences of injury severity m ean between new hire and non-new hire workers by age. (Independent Sample t-test statistic s are given for thos e comparisons which showed significant differences at p 0.05). Job Tenure Information regarding the length of time that ha d transpired from the date of hire to the date of the injury (job tenure) was provided for 12,023 workers. Over 34% of the injuries occurred within the first 60 days of employment with the firm. Figure 414 displays a decrease

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113 in injuries by tenure. Within the first 60 days of hi re an injury occurred at an approximate rate of 200 per day. For workers whose employment tenure was between 61 days and a year there was a rate of approximately 40 injuries per day. 0.99 3.13 10.03 31.43 63.51 103.70 142.83 210.93 304.93 0 to 15 Days16 to 30 Days31 to 60 Days61 to 90 Days91 to 180 Days181 to 365 Days366 to 730 Days (1 to 2 Years) 731 to 1460 Days (2 to 4 Years) > 1461 Days (Greater than 4 Years) Time between date of hire and date of injur y Figure 414. Daily injury rate by job tenure. A test for homogeneity of variance showed that an equal variance of in jury severity levels could not be assumed between the eight tenure categories, L (8, 34,170) = 5.94, p 0.05. A subsequent Welch robust test of equality of injury severity means for these eight tenure categories showed that at least one of these groups had a statistical ly significant different injury severity mean than at least one of the other groups, F (8, 391.13) = 2.66, p .01. This result was confirmed with the Tukeys b range test. The Tukeys b range test was conducted to id entify specific differen ces between injury severity means for the eight tenure categories. Figure 415 shows the dist ribution of the injury severity means, in descending injury severity mean levels, for the eight tenure categories. Workers who had a job tenure greater than 4 year s prior to the injury had the highest injury severity mean ( = 1.39). The remaining tenure categories, according to descending injury severity mean levels, are as follows: one to two years ( = 1.38), zero to 15 days ( = 1.38), two to four years ( = 1.38), between 16 and 30 days ( = 1.37), between 31 and 60 days ( = 1.36),

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114 of 91 through 180 days ( = 1.35). Workers with j ob tenure between 181 and 365 days prior to the injury event had the lowest in jury severity mean ( = 1.34). 1.39 (.62) 1.38 (.64) 1.38 (.62) 1.38 (.65) 1.37 (.61) 1.36 (.60) 1.36 (.62) 1.35 (.60) 1.34 (.61) 1.311.321.331.341.351.361.371.381.391.40 181 to 365 Days (n = 5578) 91 to 180 Days (n = 5629) 31 to 60 Days (n = 4232) 61 to 90 Days (n = 3072) 16 to 30 Days (n = 3123) 731 to 1460 Days (2 to 4 Years) (n = 2266) 0 to 15 Days (n = 4506) 366 to 730 Days (1 to 2 Years) (n = 3630) > 1461 Days (Greater than 4 Years) (n = 2143) Injury Severity Mean (Standard Deviation) Figure 415. Comparison of injury severity means by job tenure. From the homogeneous groupings of injury severity means shown in Figure 415 significant differences of injury severity means, at p 0.05, between specific job tenure categories among workers was examined (see Figur e 416). It was observed that workers who were employed for more than 4 years prior to experiencing thei r injuries had a significantly higher injury severity mean, at p 0.05, than workers who were employed between six months and one year prior to ex periencing their injuries. Occupational Work Area Information regarding the workers General Occupational Work Area (work area) was identifiable for 46,056 workers. For statistical analysis, workers, whose work area was not specified, were grouped as Workers/Unspecified Trades, with the result making up the largest

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115 group, 24.36% (n = 11,219). Injuries to workers identified as worki ng in the areas of carpentry, electrical work, and iron/steel work combined fo r about 35% of the total number of injuries (see Table 411). 1.39 (.62) 1.38 (.64) 1.38 (.62) 1.38 (.65) 1.37 (.61) 1.36 (.60) 1.36 (.62) 1.35 (.60) 1.34 (.61) 1.311.321.331.341.351.361.371.381.391.40 181 to 365 Days (n = 5578) 91 to 180 Days (n = 5629) 31 to 60 Days (n = 4232) 61 to 90 Days (n = 3072) 16 to 30 Days (n = 3123) 731 to 1460 Days (2 to 4 Years) (n = 2266) 0 to 15 Days (n = 4506) 366 to 730 Days (1 to 2 Years) (n = 3630) > 1461 Days (Greater than 4 Years) (n = 2143) Injury Severity Mean (Standard Deviation) Figure 416. Comparison of injury severity means by job tenure. The relationship of injury severity and ge neral occupational work area was examined. Homogeneity of variance of injury severity for the 42 occupational work areas was examined using the Levene statistic. The results of this statistic did not allow the assumption of equal variances, L (41, 34,424) = 12.378, p 0.05. The results of a subsequent Welch robust test of equality of injury severity means indicated that at least one of these work areas had a significantly different injury severity mean of at least one of the other work areas, F (41, 1,250.27) = 5.19, p .001; however, this was not supported by the subsequent Tukeys b range test.

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116 The Tukeys b means range test was used to rank, in descending order, the 42 work areas according to their respective injury severity means (see Figure 417). Injuries to landscape workers ( = 1.44) and technicians/mechanics ( = 1.44) ranked as the most severe, followed by injuries to roofers ( = 1.43), fl ag persons ( = 1.43), and Floori ng, tile, or carpeting workers ( = 1.42), the five worker areas with the highest injury severity means. Injuries to clerical workers ( = 1.22) ranked the lowest with re spect to injury severity mean. In combination with injuries to clerical workers, injuries to professional engi neers ( = 1.24), acoustic ceiling installers ( = 1.25), field engineers ( = 1.25) and welders ( = 1.25) had the five lowest ranked injury severity means. The Tukeys b test did not id entify any specific, significantly different, at p 0.05, injury severity means between any of the work areas. Occupational Experience Level by General Occupational Work Area Injury information was provided on eight cate gories of worker o ccupational experience level for 14,383 workers (seeTable 412). Laborer s (n = 7,917) made up just over 55% of the workers. Apprentice level workers (n = 1,578), foremen (n = 1,449), and journeymen (n = 1,358) each accounted for about 10% of the injuries. Injuri es to helpers or assistants (n = 752) made up slightly over five % of the injuries for the eigh t occupational experience le vels. Injuries to field supervisors (n = 614), administrative personnel (n = 448) and professional level workers (n = 267) combined to account for less than 10% of the injuries. Injury severity by occupational experience level was examined. The results of the Levene test did not support an assumption of equal variance s of injury severity scores for the eight occupational experience levels, L (7, 14,230) = 10.14, p < 0.001. The results of the subsequent Welch test indicated that at l east one of the experience levels was significantly different, with regards to respective in jury severity means, of one of the other levels, F (7, 2,053.70) = 4.10, p < 0.001. Figure 417 shows that this result was confirmed by the resu lts of the Tukeys range test.

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117 Table 411. Injuries by occupational work areas of injured workers. Occupational work area Number of injuries % Cumulative % Workers/unspecified trades 1121924.36%24.36% Carpentry 648814.09%38.45% Electrical 537511.67%50.12% Iron/steel 42279.18%59.30% Technical repair and maintenance 20594.47%63.77% Concrete 20474.44%68.21% Pipe fitting/laying 19944.33%72.54% Plumbing 13682.97%75.51% Masonry 12782.77%78.29% Epuiment or machinery operations 12782.77%81.06% Sheet metal 12252.66%83.72% Boilermaking 10372.25%85.97% Welding 6971.51%87.49% Millwright work 6871.49%88.98% Supervising 5831.27%90.24% Painting/ plasterering 5581.21%91.45% Drywall 4941.07%92.53% Driving 3490.76%93.28% Insulation 3310.72%94.00% Lineman 2760.60%94.60% Glazing 2530.55%95.15% Clerical 2530.55%95.70% Roofing 2520.55%96.25% Steam fitting 2390.52%96.77% Managing 1950.42%97.19% Sprinkler fitting 1640.36%97.55% Inspecting 1440.31%97.86% Flooring, tile, carpeting 1380.30%98.16% Engineering 1210.26%98.42% Scaffold erection 1080.23%98.66% Security 830.18%98.84% Lathing 790.17%99.01% Conveyor systems work 770.17%99.18% HVAC/refrigeration 620.13%99.31% Waterproofing 560.12%99.43% Rigging 510.11%99.54% Material handling 510.11%99.65% Surveying 350.08%99.73% Hod carrying 330.07%99.80% Field engineering 310.07%99.87% Landscaping 250.05%99.92% Acoustic ceiling work 210.05%99.97% Flagging 150.03%100.00% Total 46056100.00%

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118 1.22 (.51) 1.24 (.58) 1.25 (.55) 1.25 (.52) 1.25 (.55) 1.26 (.60) 1.27 (.53) 1.27 (.56) 1.27 (.54) 1.27 (.51) 1.28 (.45) 1.28 (.53) 1.29 (.57) 1.29 (.56) 1.30 (.53) 1.30 (.57) 1.30 (.52) 1.31 (.61) 1.31 (.75) 1.31 (.54) 1.31 (.54) 1.32 (.55) 1.32 (.47) 1.33 (.63) 1.35 (.62) 1.36 (.62) 1.36 (.60) 1.36 (.63) 1.36 (.59) 1.37 (.56) 1.37 (.56) 1.39 (.63) 1.40 (.57) 1.40 (.58) 1.41 (.50) 1.41 (.69) 1.41 (.71) 1.42 (.55) 1.43 (.65) 1.43 (.59) 1.44 (.66) 1.44 (.77) 1.101.151.201.251.301.351.401.451.50 Administrative Clerical Workers (n = 250) Engineers (n = 119) Acoustic Ceiling Installers (n = 20) Field Engineers (n = 28) Welders (n = 691) Steam Fitters (n = 239) Sprinkler Fitters (n = 161) Plumbers (n = 1351) Sheet Metal Workers (n = 1208) Scaffold Erectors (n = 106) HVAC/Refrigeration Workers (n = 61) Insulators (n = 320) Boilermaker (n = 1030) Pipe Fitters/Layers (n = 1981) Drywall Workers (n = 486) Electricians (n = 5281) Lathers (n = 79) Supervisory (n = 575) Managers (n = 192) Conveyor Systems Workers (n = 77) Surveyors (n = 32) Material Handlers (n = 50) Waterproofers (n = 53) Iron/Steel Workers (n = 4184) Millwright Workers (n = 685) Concrete Workers (n = 2042) Carpenters (n = 6443) Glazers (n = 246) Masons (n = 1271) Inspectors (n = 144) Security Workers (n = 81) Equipment/Machinery Operators (n = 1257) Riggers (n = 50) Painters/ Plasterers (n = 556) Hod Carriers (n = 32) Drivers (n = 346) Lineman (n = 271) Florring/Tile/Carpeting Workers (n = 136) Flag Persons (n = 14) Roofers (n = 247) Technician (n = 2046) Landscape Workers (n = 25)Injury Severity Mean (Standard Deviation) Figure 417. Comparison of injury seve rity means by occupational work area.

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119 Table 412. Injuries by occupational experience level of injured worker Occupational Experience Level Numb er of injuries % Cumulative % Laborer 7,91755.04% 55.04% Apprentice 1,57810.97% 66.01% Foreman 1,44910.07% 76.09% Journeyman 1,3589.44% 85.53% Helper/assistant 7525.23% 90.76% Field supervisor 6144.27% 95.02% Administrator 4483.11% 98.14% Professional 2671.86%100.00% Total 14,383100.00% Of the Tukeys b range test, it was shown that journeymen had the highest injury severity mean ( = 1.39), followed by foremen ( = 1.35), laborers ( = 1.35), professionals ( = 1.31), apprentices ( = 1.31), field supervisory level worker s, ( = 1.30) and helper s or assistants ( = 1.30). Administrative level worker s had the lowest associated in jury severity mean ( = 1.26) (see Figure 418). Two homogeneous groups of injury severity means were identifie d, thus supporting the results of the Welch test (see Fi gure 418). It was further dete rmined that journeymen had a significantly greater injury severity mean, at p 0.05, than that for administrative level personnel (see Figure 419). 1.26 (.63) 1.30 (.56) 1.30 (.61) 1.31 (.57) 1.31 (.57) 1.35 (.59) 1.35 (.61) 1.39 (.62)1.151.201.251.301.351.40Administrative (n = 442) Helper/assistant (n = 738) Field supervisor (n = 603) Apprentice (n = 1567) Professional (n = 265) Laborer (n = 7839) Foreman (n = 1434) Journeyman (n = 1350)Injury Severity Mean (Standard Deviation) Figure 418. Comparison of injury severity means by occupational experience level.

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120 1.39 (.62) 1.35 (.61) 1.35 (.59) 1.31 (.57) 1.31 (.57) 1.30 (.61) 1.30 (.56) 1.26 (.63)1.151.201.251.301.351.40Administrative (n = 442) Helper/assistant (n = 738) Field supervisor (n = 603) Apprentice (n = 1567) Professional (n = 265) Laborer (n = 7839) Foreman (n = 1434) Journeyman (n = 1350)Injury Severity Mean (Standard Deviation) Figure 419. Differences of injury severity means between occupational experience levels. Laborers The occupational experience level of workers was examined further for specific work areas. Table 413 shows information on injuries was distributed by the occupational work areas for laborers, which was provided for 4,350 workers. Over 39% of the laborers were concrete workers (n = 1,700). Almost 24% of the laborers were associated with electrical work (n = 1,023), and slightly less than 20% of the laborers were involved in carpentry work (n = 833). Workers working in masonry (n = 375) or steel work (n = 368) areas each accounted for almost 9% of the injuries to laborers. Among laborers, sheet metal workers account for less than 2% of the workers (n = 51). Table 413. Injuries by occupational work area for laborers. Occupational work area Number of injuries % Cumulative % Concrete 1,70039.08%39.08% Electrical 1,02323.52%62.60% Carpentry 83319.15%81.75% Masonry 3758.62%90.37% Iron/steel 3688.46%98.83% Sheet metal 511.17%100.00% Total 4,350100.00% The results of the Levene test supported an assumption of equal variances of injury severity scores for the six occupational areas for laborers, L (5, 4,339) = 2.05, p > 0.05. The results of the subsequent ANOVA test indicated that none of the occupational areas among

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121 laborers had a significantly different injury severity of one of th e other work areas, F (5, 4,339) = 2.39, p > 0.20. This result was confirmed by th e results of the Tukeys range test. Despite the lack of any significant diffe rence of injury se verity means, at p 0.05, between the work areas for laborers, a ranking of work areas by injury severity means was developed of the Tukeys b range test (see Figu re 420). It was shown that la borers doing electrical work had the highest injury severity mean ( = 1.40), fo llowed by masonry work ( = 1.37), carpentry ( = 1.36), concrete work ( = 1.35), a nd iron and steel work ( = 1.32) Laborers involved in sheet metal work at the time of the injury had the lowest injury severity mean ( = 1.29). 1.29 (.61) 1.32 (.57) 1.35 (.62) 1.36 (.59) 1.37 (.58) 1.40 (.60)1.241.281.321.361.401.44Sheet metal (n = 51) Iron/steel (n = 368) Concrete (n = 1,697) Carpentry (n = 833) Masonry (n = 375) Electrical (n = 1,021)Injury Severity Mean (Standard Deviation) Figure 420. Comparison of injury severity means by occupational work area for laborers. Helpers or Assistants Information regarding injuries by occupational work areas fo r helpers and assistants is shown on Table 414. This information was pr ovided for 439 workers. Over 25% of the helpers/assistants were involved in electrical work (n = 112), and approximately 18% of the helpers/assistants were involved in pipe fitting or pipe laying (n = 80). Almost 15% of the helpers/assistants sustained injuries when perf orming plumbing activities (n = 64). Slightly over 6% of the helpers/assistants were injured while either working with sheet metal (n = 28) or welding (n = 28).Each of the following work areas was associated with around five % or less of all the injuries to helpers or assistants: Masonry (n = 23) Iron/steel (n = 19)

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122 Technical repair and maintenace (n = 16) Painting or plastering (n = 13) Boilermaker (n = 11) Flooring, tile, or carpeting (n = 11) Insulation (n = 11) Conveyor systems (n = 7) Glazing (n = 2) HVAC/refrigeration (n = 1) Rigging (n = 1) Table 4-14. Occupational work area of injured helpers and assistants. Occupational work area Number of injuries % Cumulative % Electrical 11225.51% 25.51% Pipe fitting 8018.22% 43.73% Plumbing 6414.58% 58.31% Sheet metal 286.38% 64.69% Welding 286.38% 71.07% Masonry 235.24% 76.31% Iron/steel 194.33% 80.64% Technical repair and maintenace 163.64% 84.28% Painting and plastering 132.96% 87.24% Millwright work 122.73% 89.97% Boilermaker 112.51% 92.48% Flooring, tile, and carpeting 112.51% 94.99% Insulation 112.51% 97.49% Conveyor systems work 71.59% 99.09% Glazing 20.46% 99.54% HVAC/refrigeration 10.23% 99.77% Rigging 10.23% 100.00% Total 439100.00% Because of the frequencies for both HVAC/Re frigeration and Rigging being below two, a Tukeys range test for the injury severity m eans could not be conducted. The results of an ANOVA showed that none of the occupational work areas differed significantly from one another with respect to injury severity means, F (16, 410) = 0.90, p > 0.50. Figure 421 shows the ranking of 17 occupational ar eas, by injury severity mean.

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123 Apprentice Information regarding the general occupationa l work area of the a pprentice level worker was provided for 1,393 workers. Table 415 displays the distribution of these injuries by occupational work area for apprentices. Over 25% of the apprentices were performing electrical work (n = 367) and 25% were performing carpentry (n = 355) when they were injured. Almost 15% were involved in plumbing work (n = 214). Iron and steel work (n = 116) accounted for almost 12% of the injuries to apprentices. Workers working with concrete (n = 81) or sheet metal (n = 57) combined for almost 10% of the inju ries to apprentices. The combination of the following work areas was associated with slightly more than 10% of the injuries to apprentices: masonry (n = 44, 3.16%), millwright (n = 35, 2.5 1%), painting or plastering (n = 33, 2.37%), sprinkler fitting (n = 17, 1.22%), boilermaker (n = 10, 0.72%), glazing (n = 10, 0.72%), flooring, tile, and carpeting (n = 4, 0.29%). 1.00 (.00) 1.00 (*) 1.00 (*) 1.11 (.42) 1.18 (.43) 1.21 (.42) 1.24 (.49) 1.25 (.45) 1.27 (.47) 1.29 (.49) 1.31 (.48) 1.31 (.56) 1.33 (.69) 1.36 (.66) 1.42 (.79) 1.55 (.69) 1.56 (.52) 0.000.200.400.600.801.001.201.401.601.80 Glazing (n = 2) HVAC/refrigeration (n = 1) Rigging (n = 1) Welding (n = 28) Plumbing (n = 64) Sheet metal (n = 28) Pipe fitting (n = 80) Technical maintenance and repair (n = 16) Insulation (n = 11) Conveyor systems (n = 7) Painting/plastering (n = 13) Electrical (n = 112) Iron/steel (n = 19) Masonry (n = 23) Millwright (n = 12) Flooring, tile, carpeting (n = 11) Boilermaker (n = 11) Injury Severity Mean (Standard Deviation) Figure 421. Comparison of injury severity m eans by occupational work area of injured helpers or assistants.

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124 Table 415. Injuries to apprenti ces by occupational work area. Occupational work area Number of injuries % Cumulative % Electrical 36726.35% 26.35% Carpentry 35525.48% 51.83% Plumbing 21415.36% 67.20% Iron/steel 16611.92% 79.11% Concrete 815.81% 84.93% Sheet metal 574.09% 89.02% Masonry 443.16% 92.18% Millwright work 352.51% 94.69% Painting and plastering 332.37% 97.06% Sprinkler fitting 171.22% 98.28% Boilermaker 100.72% 99.00% Glazing 100.72% 99.72% Flooring, tile, and carpeting 40.29%100.00% Total 1,393100.00% A Levene test of homogeneity of variances of injury severity scores for the 13 occupational work areas showed that an assumption of equal variances could not be made, L (12, 1,369) = 7.90, p < 0.001. The results of the subsequent Welch test of equality of in jury severity means indicated that at least one of the occupational work areas among apprentices had a significantly different injury severity mean than one of the other work areas, F (12, 75.24) = 2.84, p < 0.01. This was not confirmed by the resu lts of the Tukeys b range test. The Tukeys b range was used to rank the occupational areas for apprentices by their respective injury severity means and to detect sp ecific differences of the injury severity mean between the 13 occupational areas. Th e results of this test are show n in Figure 422. No specific significant difference, at p 0.05, of injury severity means was detected between any of the occupational areas among apprenti ces. Glazing ( = 1.50) and flooring, tile, carpeting ( = 1.50) work ranked the highest in terms of injury severity mean levels among apprentices. Sheet metal work ( = 1.16) and sprinkler fitting work ( = 1.18) displayed the lowest injury severity means among the occupational work areas for apprentices.

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125 1.16 (.46) 1.18 (.39) 1.22 (.47) 1.25 (.52) 1.26 (.51) 1.33 (.50) 1.34 (.53) 1.36 (.72) 1.40 (.65) 1.41 (.62) 1.48 (.57) 1.50 (.58) 1.50 (.71) 0.000.200.400.600.801.001.201.401.60 Sheet metal (n = 55) Sprinkler fitting (n = 17) Electrical (n = 364) Plumbing (n = 213) Millwright (n = 34) Boilermaker (n = 9) Masonry (n = 44) Iron/steel (n = 166) Concrete (n = 81) Carpentry (n = 352) Painting or plastering (n = 33) Flooring, tile, carpeting (n = 4) Glazing (n = 10) Injury Severity Mean (Standard Deviation) Figure 422. Comparison of injury severity means by occupational work areas for injured apprentices. Journeyman Information regarding the gene ral occupational work area of the journeyman level workers was provided for 890 workers. Table 416 show s the injury distribut ion by the occupational work areas for journeymen. Over 27% of the jo urneymen were performing masonry work (n = 246), and over 26% were involved in electrical work (n = 238) at the time of their injuries. Injuries occurring while involve d in carpentry work (n = 125, 14.04%) combined with sheet metal work (n = 123) accounted for almost 28% of the injuries to journeyman level workers. Almost 16% of the journeymen injuries were asso ciated with plumbing (n = 82) and pipe fitting (n = 60) work. Work as linemen (n = 14), painters or plasterers (n = 2), was associated with less than 2% of the injuries to journeyman level workers. A Levene test of homogeneity of variances of injury severity scores for the eight occupational work areas showed that an assumpti on of equal variances could not be made, L (7, 877) = 5.07, p < 0.001. The results of the subsequent Welc h test of equality of injury severity

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126 means indicated that none of the occupational work areas among journeymen had a significantly different injury severity mean than and other work areas, F (7, 18.87) = 1.97, p > 0.10. This was confirmed by the results of the Tukeys b range test. Table 416. Injuries to journeym en by occupational work area. Occupational work area Number of injuries % Cumulative % Masonry 24627.64% 27.64% Electrical 23826.74% 54.38% Carpentry 12514.04% 68.43% Sheet metal 12313.82% 82.25% Plumbing 829.21% 91.46% Pipe fitting/laying 606.74% 98.20% Lineman work 141.57% 99.77% Painting and plastering 20.22% 100.00% Total 890100.00% The Tukeys b range was used to rank the ei ght occupational areas for journeyman level workers by their respective injury severity means. The results of th is test are reflected in Figure 423. No significant difference, at p 0.05, of injury severity means was detected between any of the occupational areas among journeymen. Ca rpentry ( = 1.52) had the highest injury severity mean among journeymen, followed by painting or plastering ( = 1.50), plumbing ( = 1.49), and pipe fitting or laying ( = 1.43). Journeyman level linemen had the lowest injury severity mean ( = 1.21), preceded by journeym en sheet metal workers ( = 1.25), electrical workers ( = 1.36) and mas onry workers ( = 1.37). 1.21 (.58) 1.25 (.47) 1.36 (.58) 1.37 (.62) 1.43 (.67) 1.49 (.63) 1.50 (.71) 1.52 (.75)0.000.200.400.600.801.001.201.401.60 Lineman (n = 14) Sheet metal (n = 123) Electrical (n = 236) Masonry (n = 246) Pipe fitting or laying (n = 60) Plumbing (n = 82) Painting or plastering (n = 2) Carpentry (n = 122) Injury Severity Mean (Standard Deviation) Figure 423.Comparison of injury severity means by occupational work areas for injured journeymen.

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127 Foreman The injuries of foremen were examined. Table 417 displays the distribution of injuries for four occupational work areas of journeymen, based on information provided for 269 workers. Almost 60% of the injuries to foremen were a ssociated with carpentry work ( = 161). Foremen associated with electrical work accounted for over 26% (n = 71) of the injuries. Masonry work (n = 29, 10.78%) and concrete work (n = 8, 2.97%) accounted for slightly over 13% of the injuries to foremen. Table 417. Injuries to fore men by occupational work area. Occupational work area Number of injuries % Cumulative % Carpentry 16159.85%59.85% Electrical 7126.39%86.24% Masonry 2910.78%97.02% Concrete 82.97%100.00% Total 269100.00% The Levene test of homogeneity of variances of injury severity scores for the four occupational work areas identified among fo remen showed that an assumption of equal variances of injury severity scores for the f our occupational areas could be made, L (3, 265) = 2.32, p > 0.07. The results of the subsequent ANOVA test indicated that none of the occupational work areas among foremen had a significantly different injury severity mean than any of the other work areas, F (3, 265) = 1.34, p > 0.30. This was confirmed by th e results of the Tukeys b range test. The Tukeys b range was used to rank the eight occupational areas for foreman by their respective injury seve rity means. The results of this test are reflected in Figure 424. Masonry work ( = 1.52) had the highest injury severity mean among foremen, followed by carpentry ( = 1.48), and electrical work ( = 1.31). Foremen associated with concrete work ( = 1.25) had the

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128 lowest injury severity mean. No significant difference, at p 0.05, of injury severity means was detected between the occupational areas of foremen. 1.25 (.46) 1.31 (.60) 1.43 (.69) 1.52 (.69) 0.000.200.400.600.801.001.201.401.60 Concrete (n = 8) Electrical (n = 71) Carpentry (n = 161) Masonry (n = 29) Injury Severity Mean (Standard Deviation) Figure 424. Comparison of injury severity means by occupational work areas for injured foremen.. Supervisors Information regarding injuries by the two general occupational area categories for field supervision level workers was provi ded in 614 cases. Table 418 di splays the injury distribution by the two occupational work areas for field supervisors. Almost 95% of the injuries to field supervisors were associated with superintendents (n = 583) while slightly more than five % of the injuries associated with field supervision level workers were to fi eld engineers (n = 31). Table 418. Injuries to supervis ors by occupational work area. Occupational work area Number of injuries % Cumulative % Superintendent 58394.95% 94.95% Field Engineers 315.05%100.00% Total 614100.00% An independent t-test was conducted to compar e injury severity means of the two general occupational work areas associated with field supervision. The re sults of the Levene test for equality of injury severity score variances for superintendents and field engineers allowed for the assumption of equal variances, L (601) = 0.84, p > 0.30. As Figure 425 illust rates, the results of the subsequent t-test showed that, among field s upervision level workers, superintendents ( =

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129 1.31) did not had a significantly diff erent injury severity mean than that of field engineers ( = 1.25), t (601) = 0.48, p > 0.60. 1.25 (.52) 1.31 (.61) 1.201.251.301.35 Field engineer (n = 28) Superintendent (n = 575) Injury Severity Mean (Standard Deviation) Figure 425. Comparison of injury severity means by occupational work area of injured supervisors. Professional Information regarding the frequency of in juries associated with the two general occupational work areas identified as professi onal level workers was provided for 265 injured workers (see Table 419). Slightly more than 45 % of the injuries to professionals were to some type of professional engineer (n = 121). The remaining injuries to professional level workers were experienced by inspectors (n = 144, 54.34%). Table 419. Injury to professiona ls by occupational work area. Occupational work area Number of injuries % Cumulative % Inspector 14454.34% 54.34% Professional engineer 12145.66%100.00% Total 265100.00% An independent t-test was conducted to compar e injury severity mean s for the two general occupational work areas associated with professi onal level workers. The results of the Levene test for equality of injury severity score variances for inspectors and professional engineers did not allow for the assumption of equal variances, L (261) = 5.67, p < 0.02. The results of the subsequent t-test showed that among professional level workers, inspectors ( = 1.37) did not had a significantly different injury severity mean than that of professional engineers ( = 1.24), t (261) = 1.75, p > 0.08 (see Figure 426).

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130 1.24 (.58) 1.37 (.56) 1.101.151.201.251.301.351.40 Professional engineer (n = 121) Inspector (n = 144) Injury Severity Mean (Standard Deviation) Figure 426. Comparison of injury severity means by occupational work areas of injured professionals. Administrators Information for 448 injured workers was provided where the genera l occupational work area was identified as administrative. Table 420 shows that over 56% of the injured administrative level workers were office and cl erical workers (n = 253). The remaining 43.53% of the workers were managers of some type (n = 195). Table 420. Injuries to administ rators by occupational work area. Occupational work area Number of injuries % Cumulative % Clerical 253 56.47% 56.47% Management 195 43.53%100.00% Total 448 100.00% An independent t-test was conducted to compar e injury severity mean s for the two general occupational work areas associated with administ rative level workers. The results of the Levene test for equality of injury severity score variances for managers and office/clerical workers did not allow for the assumption of equal variances, L (440) = 7.713, p < 0.01. The results of the subsequent t-test showed that, among administ rative level workers, even though managers had the higher injury seve rity mean ( = 1. 31), it wa s not significantly different of the injury severity mean associated with office and cleri cal workers ( = 1.22), t (440) = 1.38, p > 0.10 (see Figure 427). Nature of Injury Information on the Nature of Injury was provided for 41,475 workers. Strain injuries were the most common injuries to workers (n = 11,936). Table 421 shows that over 80% of all

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131 the injuries to workers were distributed be tween strains (n = 11,936), lacerations (n = 6,779), contusions (n = 5,863), foreign bodies (n = 3,876), sprains (n = 2,534) and fractures (n = 2,446). The severity of injury was examined with respect to the Nature of Injury categories. The Levene statistic was conducted to check for homogene ity of variance of injury severity scores for the 36 Nature of Injury categories. This statis tic revealed that equal variance between the age groups could not be assumed, L (35, 40,858) = 274.93, p .001. The results of the Welch robust test of equality of means show ed that at least one of the nature of injury groups had a significantly different injury severity mean than another category, F (35, 579.40) = 95.51, p .01. This was confirmed by the subsequent Tukeys b range test. 1.22 (.51) 1.31 (.75) 1.151.201.251.301.35 Clerical (n = 250) Management (n = 192) Injury Severity Mean (Standard Deviation) Figure 427. Comparison of injury severity means by occupational work areas of injured administrators. The top ten ranked nature of injury, according to injury severity mean are shown in Figure 428. Myocardial infarctions ( = 2.63) and silic osis ( = 2.63) showed significantly higher, at p 0.05, injury severity means than all of the rema ining Nature of Injury categories. Ruptures ranked third in severity ( = 2.27) and this was shown to significantly greater, at p 0.05, than all of the remaining Nature of Injury groups, except amputat ions ( = 2.27). Figure 429 displays the bottom ten, by injury se verity mean, nature of injury classifications. Enucleations ( = 1.00) showed the lowest injury severity mean, preceded by injuries of foreign bodies ( = 1.04), dermatitis ( = 1.07), punctures ( = 1.12) and lacerations ( = 1.17). Injuries of poisoning ranked 30th out of the 36 nature of injuries ca tegories, = 1.20. This was preceded by

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132 inflammations ( = 1.21), contus ions ( = 1.22), heat prostration ( = 1.22), and burns ( = 1.24). Table 421. Injuries by nature of injury Nature of injury Number of injuries % Cumulative % Strain 11,93628.78%28.78% Laceration 6,77916.34%45.12% Contusion 5,86314.14%59.26% Foreign body 3,8769.35%68.61% Sprain 25346.11%74.72% Fracture 24465.90%80.61% Puncture 2,0524.95%85.56% Inflammation 1,0772.60%88.16% Burn 8832.13%90.29% Multiple injuries 7011.69%91.98% Crushing 4661.12%93.10% Rupture 4501.08%94.19% Hernia 3870.93%95.12% Infection 2170.52%95.64% Dislocation 2080.50%96.14% Respiratory disorder 1920.46%96.61% Asbestosis 1820.44%97.05% Dermatitis 1510.36%97.41% Electric shock 1220.29%97.70% Heat prostration 1200.29%97.99% Occupational disease NOC 1200.29%98.28% Carpal tunnel sryndrome 960.23%98.51% Chemical poisoning 910.22%98.73% Amputation 860.21%98.94% Concussion 790.19%99.13% Severance 670.16%99.29% Hearing loss or impairment 590.14%99.43% Poisoning NOC 590.14%99.58% Myocardial infarction 470.11%99.69% Mental stress/disorder 330.08%99.77% Enucleation 310.07%99.84% Syncope 200.05%99.89% Asphyxiation 190.05%99.94% Angina pectoris 90.02%99.96% Freezing 90.02%99.98% Silicosis 80.02%100.00% Total 41,475100.00%

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133 1.75 (.85) 1.86 (.77) 1.87 (.70) 1.89 (1.27) 1.92 (.54) 1.94 (.66) 1.95 (.73) 2.27 (.68) 2.37 (.60) 2.63 (.52) 2.63 ( 1.36) 0.000.501.001.502.002.503.00 Multiple Injuries (n = 697) Dislocation (n = 207) Carpal Tunnel Syndrome (n = 95) Angina Pectoris (n = 9) Hernia (n = 386) Mental Stess/Disorder (n = 33) Severence (n = 66) Amputation (n = 86) Rupture (n = 449) Silicosis (n = 8) Myocardial Infarction (n = 43) Injury Severity Mean (Standard Deviation) Figure 428. Comparison of injury severity means by top ten nature of injury. 1.00 (.30) 1.04 (.24) 1.07 (.26) 1.12 (.38) 1.17 (.46) 1.20 (.48) 1.21 (.49) 1.22 (.50) 1.23 (.50) 1.24 (.53) 0.000.200.400.600.801.001.201.40 Enucleation (n = 31) Foreign Body (n = 3827) Dermatitis (n = 147) Puncture (n = 2026) Laceration (n = 6660) Poisoning Chemical (n = 91) Inflammation (n = 1056) Contusion (n = 5730) Heat of Prostration (n = 118) Burn (n = 871) Injury Severity Mean (Standard Deviation) Figure 429. Injury severity means for the bottom ten nature of injury.

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134 Each of the Nature of Injury categories were assigned to one of the following three General Nature of Injury categories: Specific Injury, Occupational Disease or Cumulative Injury, and Multiple Injuries. Table 422 shows th e injury distribution for these General Nature of Injury categories. Specific injuries comprised over 96% (n = 44,360) of the total number of recorded injuries (n = 46,018). Multiple injuries (n = 701) and occupational diseases or cumulative injuries (n = 957) combined were less than 4% of the injuries. Table 422. Injuries by general nature of injury. General nature of injury Numb er of injuries % Cumulative % Specific injury 44,36096.40%96.40% Occupational disease or cumulative injury 9572.08%98.48% Multiple injuries 7011.52%100.00% Total 46,018100.00% The relationship between injury severity a nd the general nature of the injury was examined. The results of the Levene test for hom ogeneity of variance of injury severity scores between the three General Natu re of Injury categories did not allow an assumption of equal variance, L (2, 45,338) = 101.40, p 0.05. The results of a subsequent Welch robust test of equality of injury severity means for the General Nature of Injury categor ies showed that at l east one of the General Nature of Injury categories had a significantly different injury severity mean than another category, F (2, 1,084.87) = 101.40, p .001. This was confirmed by the subsequent Tukeys b range test which identified specific injury severity means differences between th e three categories. The results for the Tukeys b test are displayed in Figure 4. Multiple injuries had the highest injury severity mean ( = 1.75), followed by occupational di s eases or cumulative injuries ( = 1.43), and the least severe in juries occurred within the speci fic injuries category ( = 1.32). Three homogeneous subsets of severity mean s were identified by the Tukeys b test.

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135 1.75 (.85) 1.43 (.64) 1.32 (.59)0.000.200.400.600.801.001.201.401.601.802.00Specific injury (n = 43717) Occupational disease or cumulative injury (n = 927) Multiple injuries (n = 697) Injury Severity Mean (Standard Deviation) Figure 430. Comparison of injury severity means by general nature of injury. It was discerned from the three subsets s hown in Figure 430 that multiple body part injuries had a significantly higher severity mean, at p 0.05, than that for both occupational disease and cumulative injuries, and for specific injuries (see Figure 431). Occupational diseases and cumulative injuries had a significantly greater severity mean, at p 0.05, than specific injuries. 1.75 (.85) 1.43 (.64) 1.32 (.59)0.000.200.400.600.801.001.201.401.601.802.00Specific injury (n = 43717) Occupational disease or cumulative injury (n = 927) Multiple injuries (n = 697) Injury Severity Mean (Standard Deviation) Figure 431. Comparison of injury severity means by general nature of injuries. The distribution of Specific Injuries by the G eneral Nature of Injury is shown in Table 423. Strains constituted almost 30% (n = 11,936) of the Specific Injuri es experienced by the workers. Lacerations (n = 6,779) and contusions (n = 5,863), t ogether, comprised over 30% of the Specific Injuries. Foreign body (n = 3,876), sprains (n = 2,534), fractures (n = 2,446), and punctures (n = 2,052) combined to represent about 27% of the Specific Injuries. Angina

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136 pectoris (n = 9, 0.02%) and freezing (n = 9, 0.02%) each occurred in less than 0.05% of the injury cases. Around 0.05% of the reported cases were either asphyxiation (n = 19) or syncope (n = 20). Syncope is the loss of c onsciousness resulting of insufficient blood flow to the brain. Enucleation, the removal of a part of the body, (e.g. eyeball) without cutting into the body, accounted in 0.08% (n = 31) of the Specific Injuries. Myocardial infarctions (n = 47), general poisoning (n = 47), and severances (n = 67) each accounted for less than 0.20% of the specific injuries to workers. Amputations (n = 86) a nd concussions (n = 79) each constituted about 0.20% of the specific injuries to workers. Electric shocks (n = 122) and heat prostration (n = 120) accounted for around 0.30% of all the specific injuri es to workers. Dislocations (n = 208) and infections (n = 217), accounted for sl ightly over one % of the entire specific injuries to workers. Hernias (n = 387) amounted to ju st less than one % of the specific injuries to workers. Ruptures (n = 450) and crushing (n = 466) each accounted for nearly 1.15% of the specific injuries. Inflammations (n = 1,077) and burns (n = 883) toge ther accounted for slightly less than five % of the specific injuries to workers. The Multiple Injuries category of General Na ture of Injury const ituted its own Nature of Injury subcategory. Respiratory disorders (n = 192) and asbestosis (n =182) comprised over two thirds of the injuries within the Occupa tional Disease or Cumulative Injury category for General Nature of Injury (see Table 424). Silicosis was the least represented (n = 8). All 26 categories of Specific Injury were further examined to identify possible differences between injury severity means (see Figure 432). Equal in jury severity score variances for the Specific Inju ry in the Nature of Injury category was not assumed, L (25, 39,268) = 376-68, p 0.05. Following the Welch robust test of equality of injury severity means it was found that at least one of the Specific In jury categories had a significantly different

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137 Table 423. Specific injuri es by nature of injury. Nature of Injury Number of injuries % Cumulative % Strain 11,93629.96% 29.96% Laceration 6,77917.01% 46.97% Contusion 5,86314.72% 61.69% Foreign body 3,8769.73% 71.42% Sprain 2,5346.36% 77.78% Fracture 2,4466.14% 83.92% Puncture 2,0525.15% 89.07% Inflammation 1,0772.70% 91.77% Burn 8832.22% 93.99% Crushing 4661.17% 95.16% Rupture 4501.13% 96.29% Hernia 3870.97% 97.26% Infection 2170.54% 97.80% Dislocation 2080.52% 98.32% Electric shock 1220.31% 98.63% Heat prostration 1200.30% 98.93% Amputation 860.22% 99.15% Concussion 790.20% 99.34% Severance 670.17% 99.51% Poisoning NOC 590.15% 99.66% Myocardial infarction 470.12% 99.78% Enucleation 310.08% 99.86% Syncope 200.05% 99.91% Asphyxiation 190.05% 99.95% Angina pectoris 90.02% 99.98% Freezing 90.02% 100.00% Total 39,842100.00% Table 424. Occupational diseases or cu mulative injuries by nature of injury. Nature of injury Number of injuries % Cumulative % Respiratory disorder 19220.60% 20.60% Asbestosis 18219.53% 40.13% Dermatitis 15116.20% 56.33% Occupational disease NOC 12012.88% 69.21% Carpal tunnel sryndrome 9610.30% 79.51% Chemical poisoning 919.76% 89.27% Hearing loss or impairment 596.33% 95.60% Mental stress/disorder 333.54% 99.14% Silicosis 80.86%100.00% Total 932100.00%

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138 injury severity mean of the othe r categories (F = 268.92; df = 25, 39,268; p 0.05). Figure 432 shows resulting ranking of injury severity m eans for the Specific Injuries following the Tukeys b range test. Specific injuries with the te n lowest injury severity means, of highest to lowest, include; syncope ( = 1.30), burns ( = 1. 24), heat prostration ( = 1.23), contusions ( = 1.22), inflammations ( = 1.21), lace rations ( = 1.17), punctures ( = 1.12), enucleations ( = 1.10), and injuries of foreign bodies ( = 1.04). 1.04 (.24) 1.10 (.30) 1.12 (.38) 1.17 (.46) 1.21 (.49) 1.22 (.50) 1.23 (.50) 1.24 (.53) 1.28 (.50) 1.30 (.57) 1.34 (.48) 1.37 (.59) 1.41 (.61) 1.44 (.73) 1.47 (.88) 1.54 (.85) 1.55 (.64) 1.65 (1.11) 1.70 (.70) 1.86 (.77) 1.89 (1.27) 1.92 (.54) 1.95 (.73) 2.27 (.68) 2.37 (.60) 2.63 (1.36) 0.00 0.50 1.00 1.50 2.00 2.50 3.00 Foreign Body (n = 3 827) Enucleation (n = 31) Puncture (n = 2026) Laceration (n = 6660) Inflammation (n = 1056) Contusion (n = 5730) Heat of Prostration (n = 118) Burn (n = 871) Infection (n = 214) Syncope (n = 20) Poisoning General (n = 58) Sprain (n = 2489) Strain (n = 11826) Freezing (n = 9) Electric Shock (n = 121) Crushing (n = 461) Concussion (n = 78) Asphyxiation (n = 17) Fracture (n = 2436) Dislocation (n = 207) Angina Pectoris (n = 9) Hernia (n = 386) Severence (n = 66) Amputation (n = 86) Rupture (n = 449) Myocardial Infarction (n = 43) Injury Severity Mean (Standard Deviation) Figure 432. Comparison of injury severity means by nature of injury for specific injuries.

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139 Among Specific Injuries, myocar dial infarctions had the highest injury severity mean ( = 2.63), which was significantly greater, p 0.05, than all the rema ining specific injury categories, except ruptures ( = 2.37, .60) (s ee Figure 433). Amputations ranked third in severity with a significantly higher, at p 0.05, injury severity mean ( = 2.27) than the remaining Specific Injury cate gories. Injuries of severances ( = 1.95), hernias ( = 1.92), angina pectoris (a disease marked by brief at tacks of chest pain precipitated by deficient oxygenation of the heart muscles, = 1.89) showed significantly greater injury severity means than that for all of the remaining categories, ex cept dislocations ( = 1.86), fractures ( = 1.70), and asphyxiations ( = 1.65). At p 0.05, dislocations displayed a significantly greater injury severity mean than that for injuries of electric shock, freezing, strains, sprains, poisoning, syncope, infections, and burns, heat prostration, contusions, inflammations, lacerations, punctures, enucleations, and injuries of foreign bodies. Fractures had a significantly great er injury severity mean, at p 0.05, than the same group of nature injury categories to dislocations, ex cept injuries of electric shocks, freezing, strains, and sprains. Asphyxiation related injuries had a significantly highe r injury severity mean, at p 0.05, than the same Nature of Injury groups as did fractures, except, poisoning, and syncope. Concussions showed significantly gr eater injury severities mean, at p 0.05, than that for lacerations, punctures, enucleations, and Fore ign body injuries. Injuries of crushing were significantly more severe, at p 0.05, than puncture inju ries, enucleations, and injuries attributed to foreign bodies. Electric shock injuries had a significantly greater injury severity mean, at p 0.05, than that of enucleations and injuries involving foreign bodies. Both freezing injuries and strains showed significantly greater injury severity means than that of injuries related to foreign bodies.

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140 Figure 433. Differences of injury severity means between nature of specific injuries.

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141 A similar investigation of inju ry severity means was conducted for the classifications of the Occupational Disease or Cumulative Inju ry category. Following the Levene test for homogeneity of variance of injury severity sc ores for the nine occupational disorder or cumulative injuries equal variance was not assumed, L (8, 894) = 19.79, p 0.05. A subsequent Welch robust test of the equality of injury seve rity means showed that at least one of these categories had a significantly different injury severity mean than the remaining groups ,F (8, 118.85) = 36.72, p .001. Figure 434 shows the results of a Tukeys b range test for injury severity means of the nine occupational disease/cumulative injury categories. 2.63 (.52) 1.94 (.66) 1.87 (.70) 1.63 (.59) 1.62 (.61) 1.37 (.61) 1.31 (.63) 1.20 (.48) 1.07 (.26) 0.000.501.001.502.002.503.00 Dermatitis (n = 147) Chemical poisoning (n = 91) Asbestosis (n = 166) Respiratory disorder (n = 189) All other occupational disease NOC (n = 117) Hearing loss or impairment (n = 57) Carpal tunnel syndrome (n = 95) Mental stress/disorder (n = 33) Silicosis (n = 8) Injury Severity Mean (Standard Deviation) Figure 434. Comparison of injury severity means by nature of occupational disease or cumulative injury. Among occupational diseases or cumulative in juries, silicosis showed a significantly higher injury severity mean ( = 2.63) than all of the remaining categories (significant at p 0.05) (see Figure 435). Dermatitis ( = 1.07) an d chemical poisoning ( = 1.20) were the two least severe categories and displayed significantly, at p 0.05, lower injury severity means than all but asbestosis ( = 1.31) and respiratory disorders ( = 1.37). Both mental stress ( = 1.94) or mental disorders and carpal tunnel syndrom e ( = 1.87) had significantly higher, at p 0.05, injury severity means than respiratory disorders, asbestosis, chemical poisoning and dermatitis.

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142 The injury severity mean for hearing loss or im pairment injuries ( = 1.63) was significantly higher, at p 0.05, than that for chemical poisoning and dermatitis. 2.63 (.52) 1.94 (.66) 1.87 (.70) 1.63 (.59) 1.62 (.61) 1.37 (.61) 1.31 (.63) 1.20 (.48) 1.07 (.26) 0.000.501.001.502.002.503.00 Dermatitis (n = 147) Chemical poisoning (n = 91) Asbestosis (n = 166) Respiratory disorder (n = 189) All other occupational diseases NOC (n = 117) Hearing loss or impairment (n = 57) Carpal tunnel syndrome (n = 95) Mental stress/disorder (n = 33) Silicosis (n = 8) Injury Severity Mean (Standard Deviation) Figure 435. Comparison of injury severity means by nature of occupational diseases and cumulative injuries. Cause of Injury Information regarding the number of injuri es by the General Cause of injury was provided for 43,550 injury cases (see Table 4). The three leadi ng General Cause of injury classifications were straining during an occupational activity (n = 12,324, 28.30%), followed by falling or slipping (n = 7,179, 16.48%), and being struck by som e kind of object or individual (n = 6,008, 13.80%). Table 425 shows the entire distribution of injuries for the eleven General Cause of injury categories. Moto r vehicles of some kind were the least frequent occurrences (n = 414, 0.95%). It was determined that equal variance of inju ry severity scores could not be assumed, L (10, 42,906) = 952.83, p .001. The Welch robust test of equali ty of injury severity means was conducted to examine possible differences in injury severity means between the eleven General cause of injury categories. The results of this test showed that a statistically significant difference existed between these categories with respect to injury severity means, F (10, 5,446.57) = 533.43, p .001.

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143 Table 425. General cause of injury. General cause of injury Number of injuries % Cumulative % Strain 12,32428.30% 28.30% Fall or slip 7,17916.48% 44.78% Struck by 6,00813.80% 58.58% Cut, puncture, or scrape 5,54512.73% 71.31% Foreign body 4,0939.40% 80.71% Striling against or stepping on 2,9426.76% 87.47% Caught in or between 2,3485.39% 92.86% Absorption, ingestion or inhalation 1,1972.75% 95.61% Burn 9492.18% 97.79% Animal or insected bite or sting^ 5511.27% 99.05% Motor vehicle 4140.95% 100.00% Total 43,550100.00% The Tukeyb range test was conducted to rank General cause of injury categories according to their respective mean in jury severity levels. Figure 436 shows this distribution in a descending order of injury severity magnitude. Injuries of motor vehicles ( = 1.51) and falls or slips ( = 1.50) were the highest ranked Cause of Injury classi fications, with respect to injury severity means. Injuries of st raining activity ranked third in severity ( = 1.44), followed by Caught in or between injuries ( = 1.34). The general causes of injury that have signifi cantly different injury severity means, at p 0.05, than other causes of injury are shown in Figure 437. Injuries cau sed by motor vehicles and falls or slips had significantly higher injury means than all of the remaining causes of injury. Injuries of strains showed a significantly greater in jury severity mean than all of the other causes with a lower injury severity mean. Injuries caused by being Caught in or between something were associated with a significantly greater injury severity mean than injuries caused by burns or scalds, striking against or stepping on someth ing, absorption, inhalation or ingestion of a substance, being cut, punctured or scraped, animal or insect bites or stings, and injuries caused by foreign matter in the eyes. As a group, the struck by injuries, burns and scalding injuries,

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144 injuries caused by striking agai nst or stepping on something, or absorption, inhalation, ingestion of a substance had significantly greater injury severity means than that of injuries of cuts, punctures, or scrapes, bites or stings of animal s or insects, and injuries caused by foreign matter in the eyes. Animal or insect bites or sti ngs, along with cuts, punctures and scrapes had significantly higher injury severi ty mean than injuries caused by foreign matter in the eyes. 1.04 (.25) 1.12 (.39) 1.16 (.44) 1.26 (.58) 1.26 (.55) 1.28 (.62) 1.31 (.59) 1.34 (.65) 1.44 (.62) 1.50 (.68) 1.51 (.73) 0.000.200.400.600.801.001.201.401.60 Foreign body (n = 4,040) Animal or insect bite/sting (n = 544) Cut, punctured, or scraped by (n = 5455) Absorption, ingestion or inhalation (n = 1161) Striking against or stepping on (n = 2894) Burned or scalded by (n = 935) Struck or injured by (n = 5891) Caught in or between (n = 2321) Strain by (n = 12181) Fall or slip (n = 7087) Motor vehicle (n = 408) Injury Severity Mean (Standard Deviation) Figure 436. Comparison of injury severity means by general cause of injury. 1.04 (.25) 1.12 (.39) 1.16 (.44) 1.26 (.58) 1.26 (.55) 1.28 (.62) 1.31 (.59) 1.34 (.65) 1.44 (.62) 1.50 (.68) 1.51 (.73) 0.000.200.400.600.801.001.201.401.60 Foreign body (n = 4,040) Animal or insect bite/sting (n = 544) Cut, punctured, or scraped by (n = 5455) Absorption, ingestion or inhalation (n = 1161) Striking against or stepping on (n = 2894) Burned or scalded by (n = 935) Struck or injured by (n = 5891) Caught in or between (n = 2321) Strain by (n = 12181) Fall or slip (n = 7087) Motor vehicle (n = 408) Injury Severity Mean (Standard Deviation) Figure 437. Comparison of injury severity means by general cause of injury.

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145 Burn The specific Cause of injury contributing to injuries attributed to burns or scalds is shown in Table 426. Over 25% (n = 240) of the in juries in which the General cause of injury was attributed to burns or scalds resulted of c ontact with an object or substance. Welding and electrical current combined for over 35% (n = 180) of the injuri es caused by a burn or scald. Less than 10% of the burn or scalding injuries resu lted of both temperature extremes (n = 54, 5.69%) and dust, gases, fumes, or vapors (n = 26, 2.74%). Table 426. Cause of burn injuries. Cause of injury Number of injuries % Cumulative % Contact with object or substance 24025.29% 25.29% Welding 18018.97% 44.26% Electrical current 16217.07% 61.33% Acid 12813.49% 74.82% Fire 92 9.69% 84.51% Steam or hot fluid 67 7.06% 91.57% Temperature extremes 54 5.69% 97.26% Dust, gases, fumes, or vapors 26 2.74%100.00% Total 949100.00% Severity of injury was examined by the Cause of Injury categories resulting from burns or scalding. The Levene statisti c did not allow the assumption of equal variance of injury severity scores for the nine Cause of Injury categorie s, L (7, 927) = 25.87, p .001. A subsequent Welch robust test of equality of injury severity means showed that at least one of these categories had a statistically significant diffe rent injury severity m ean than another one of categories, F (7, 219.74) = 8.74, p .001, which was confirmed by the Tukeys b range test. The Tukeys b range test was conduc ted to assess the severity of injuries of burns or scalds for the Cause of Injury categories (see Figure 438). Burns by electrical current displayed the highest injury severity mean ( = 1.49). This was followed by burns or scalding from contact with steam or hot fluids ( = 1.40) of direct contact with fire or flames ( = 1.39), exposure to

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146 dust, gases, fumes or vapors ( = 1.35), and expo sure to acid based chemicals ( = 1.32. Burns of welding operations had the lowest injury severity mean ( = 1.07) As shown in Figure 439, burns of electrica l currents had a significantly higher injury severity mean, at p 0.05, than burns attributed to temper ature extremes and welding operations. Injuries caused by being burned or scalded by either contact with steam or a hot fluid and of direct contact with fire or fl ame had significantly greater injury severity means than injuries caused by burns of welding operations. 1.49 (.91) 1.40 (.63) 1.39 (.73) 1.35 (.56) 1.32 (.62) 1.20 (.46) 1.19 (.44) 1.07 (.32) 0.000.200.400.600.801.001.201.401.60 Welding operations (n = 176) Temperature extremes (n = 54) Contact with object NOC (n = 237) Acid chemicals (n = 127) Dust, gases, fumes, or vapors (n = 26) Fire or flame (n = 90) Contact with steam or hot fluids (n = 67) Electrical current (n = 158) Injury Severity Mean (Standard Deviation) Figure 438. Comparison of injury se verity means by cause of burn injury. 1.49 (.91) 1.40 (.63) 1.39 (.73) 1.35 (.56) 1.32 (.62) 1.20 (.46) 1.19 (.44) 1.07 (.32) 0.000.200.400.600.801.001.201.401.60 Welding operations (n = 176) Temperature extremes (n = 54) Contact with object NOC (n = 237) Acid chemicals (n = 127) Dust, gases, fumes, or vapors (n = 26) Fire or flame (n = 90) Contact with steam or hot fluids (n = 67) Electrical current (n = 158) Injury Severity Mean (Standard Deviation) Figure 439. Differences of injury severi ty means between causes of burn injuries.

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147 Caught In or Between The frequencies of Caught in or between relate d injuries were examin ed by their specific their causes. The injury severi ty means for each of the specifi c causes were also compared. Those injuries resulti ng from workers being caught in or between an object being handled accounted for over 54% (n = 1,289) of the total nu mber of Caught in or between injuries. Table 427 shows that being caught in or between some type of machine or machinery was associated with 17.59% (n = 413) of Caught in or between injuries. Bein g caught in or between collapsing materials was associated with 5.20% (n = 122) of the Caught in or between injuries. Table 427. Causes of caught in or between injuries. Cause of injury Number of injuries % Cumulative % Object handled 1,28954.90% 54.90% Other NOC 52422.32% 77.22% Machine or machinery 41317.59% 94.81% Collapsing materials* 1225.20%100.00% Total 2,348100.00% Include slides of earth and building collapse. Severity of injury was examined for the four Cause of injury categor ies for Caught in or between injuries. The results of the Levene test for homogene ity of injury severity score variances did not allow for the assumption of eq ual variances for the five Cause of injury categories, L (3, 2,317) = 33.52, p .001. The subsequent Welch test of equality of injury severity means showed that at least one of these categories had a statistically significant different injury severity mean than another one of categories, F (3, 467.07) = 12.57, p .001. The results of the Tukeys b range test c onfirmed the results of the Welch test at p 0.05 (see Figure 440). Injuries cause d by being Caught in or between a machine or some kind of machinery had the highest injury severity mea n, = 1.54. Injuries caused by being Caught in or between collapsing material, which includes earth slides and building coll apses, displayed the second highest injury severi ty mean ( = 1.40), followed being Caught in or between

PAGE 148

148 miscellaneous objects not otherwise classified ( = 1.35) and objects bei ng handled by the either the injured worker and/or another worker ( = 1.28). 1.54 (.84) 1.40 (.61) 1.35 (.65) 1.28 (.58) 0.000.200.400.600.801.001.201.401.601.80 Object handled (n = 1274) Other NOC (n = 518) Collapsing materials (n = 122) Machine or machinery (n = 407) Injury Severity Mean (Standard Deviation) Figure 440. Comparison of injury severity m eans by cause of caught in or between injuries. The results of the Tukeys b range test are displayed in Figure 441. Being Caught in or between a machine or machinery ( = 1.54) resulted in a statistically higher injury severity mean, at p 0.05, than all other Caught in or between injuries. 1.54 (.84) 1.40 (.61) 1.35 (.65) 1.28 (.58) 0.000.200.400.600.801.001.201.401.601.80 Object handled (n = 1274) Other NOC (n = 518) Collapsing materials (n = 122) Machine or machinery (n = 407) Injury Severity Mean (Standard Deviation) Figure 441. Differences of injury severity means between causes of caught in or between injuries. Cut, Punctured, or Scraped Information regarding the specifi c Cause of injury associat ed with injuries generally caused by a cut, puncture or scra pe was provided for 5,450 workers. Table 428 shows the injury distribution for the five specific causes of cuts, punctures or sc rapes. Objects being lifted or handled accounted for over 40% (n = 2282) of th e cut, puncture or scrape induced injuries. Tools, powered and non-powered, accounted for near ly 30% of the injuries resulting in cuts,

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149 punctures or scrapes. Less than 2% (n = 59) of th e injuries resulting in cuts, punctures or scraps were attributed to broken glass. Table 428. Causes of injury fo r cuts, punctures, and scrapes. Cause of injury Number of injuries % Cumulative % Object being lifted or handled 2,28241.15% 41.15% Other NOC 1,58628.60% 69.75% Hand tool non-powered 89716.18% 85.93% Powered hand tool 72113.00% 98.93% Broken glass 591.06% 100.00% Total 5,545100.00% An assumption of equal variances of injury se verity scores for the five cause categories could not be made, L (4, 5,450) = 64.29, p .001. The results of the subsequent Welch robust test of equality of inju ry severity means revealed that at least one of these categories had an injury severity mean that was significantly diffe rent of one of the othe r categories, F (4, 407.42) = 14.64, p .001. A Tukeys b range test was used to rank the cau se categories for injuries resulting in a cut, puncture, or scrape, by their resp ective injury severity means (see Figure 442). Cuts, punctures or scrapes resulting from the use of powered hand tools showed the highest injury severity mean ( = 1.30) among these injuries. Cuts, punctures or scrapes caused by broken glass ranked second with respect to injury se verity mean ( = 1.21). This was followed by cuts, punctures, or scrapes from objects being lifted or handled ( = 1.14), from th e use of non-powered hand tools ( = 1.13), and miscellaneous objects not otherwise classified ( = 1.13). From the arrangement of homogeneous grouping s of the injury severity means it was shown that cuts, punctures, or scrapes of power ed hand tools had a significantly higher, at p 0.05, severity mean than all the other categories, except for cuts, punctures or scrapes of broken glass (see Figure 443).

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150 1.30 (.56) 1.21 (.45) 1.14 (.42) 1.13 (.42) 1.13 (.39) 1.001.051.101.151.201.251.301.35 Other NOC (n = 1560) Hand tool non-powered (n = 888) Object being lifted or handled (n = 2235) Broken glass (n = 58) Powered hand tool (n = 714) Injury Severity Mean (Standard Deviation) Figure 442. Comparison of injury severity m eans by causes of cuts, punctures, and scrapes. 1.30 (.56) 1.21 (.45) 1.14 (.42) 1.13 (.42) 1.13 (.39) 1.001.051.101.151.201.251.301.35 Other NOC (n = 1560) Hand tool non-powered (n = 888) Object being lifted or handled (n = 2235) Broken glass (n = 58) Powered hand tool (n = 714) Injury Severity Mean (Standard Deviation) Figure 443. Differences of injury severity means between causes of cuts, punctures, and scrapes. Fall or Slip The specific Cause of injury was provide d for 7,179 workers who fell or slipped. Table 429 shows the injury distributi on of the eleven specific causes attributed to falling or slipping. Falls and slips from ladders or scaffolds (n = 1,388) of different levels (n = 1,400) or of the same level (n = 1,569) comprised about 20 % of the total number of injuries of falls or slips. Less than 20% of the falls or slips were associated with the combined contributions of ice or snow (n = 589), slipping without a fall (n = 342), stairs (n = 328), openings (n = 313) and liquids and/or grease spills (n = 132).

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151 Table 429. Causes of injuri es from falls and slips. Cause of injury Number of injuries % Cumulative % On same level 1,56921.86% 21.86% From a different level 1,40019.50% 41.36% From a ladder or scaffold 1,38819.33% 60.70% Other NOC 1,11815.57% 76.27% On ice or snow 5898.20% 84.47% Slip (no fall) 3424.76% 89.24% On stairs 3284.57% 93.81% Into opening 3134.36% 98.17% From liquid or grease spill 1321.84%100.00% Total 7,179100.00% The results of the Levene test for homogeneity of variances of injury severity scores for the nine cause categories for falls or slips did not al low for the assumption of equal variances, L (8, 7,076) = 8.94, p .001. The results of a subsequent Welch robust test of equality of injury severity means for the nine categories showed that at least one of these categories had a injury severity mean that was significantly different of at least one other category, F (7, 1,378.45) = 17.00, p .001. A Tukeys b range test was conducted to iden tify specific differences between the means of the nine cause categories for falls or slips. As shown in Fi gure 444, the resulting ranking of the cause categories, by injury severity mean, for inju ries of falls or slips, showed falls of ladders or scaffolding as having the highest injury severity mean ( = 1.62). This was followed by injuries of falls of different levels ( = 1.60), in to openings ( = 1.52), and falls or slips on stairs ( = 1.51). Injuries caused by falls or slips on ice or snow ranked the lowest in terms of injury severity mean ( = 1.38). A further examination of the Tukeys b the re sults showed that falls from ladders or scaffolds had an injury severity mean significantly greater, at p 0.05, than that for falls or slips of liquid or grease spills, falls on the same level, other causes NOC, and injuries from falls or

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152 slips on ice or snow (see Figure 445)). Injuries caused by falls from different levels showed a significantly greater inju ry severity mean, at p 0.05, than injuries due to falls on the same level, falls or slip of causes NOC, and injuries from fa lls or slips on ice or sn ow. Falls into openings had a significantly greater injury severity mean, at p 0.05, than falls or slips from miscellaneous causes NOC, and falls or slips on ice or snow. 1.62 (.70) 1.60 (.73) 1.52 (.68) 1.51 (.69) 1.49 (.69) 1.47 (.62) 1.45 (.65) 1.39 (.62) 1.38 (.63) 1.251.301.351.401.451.501.551.601.65 On ice or snow (n = 586) Other NOC (n = 1108) From same level (n = 1537) From liquid or grease spills (n = 130) Slip (no fall) (n = 338) On stairs (n = 326) Into openings (n = 307) From different level (n = 1384) From ladder or scaffolding (n = 1371) Injury Severity Mean (Standard Deviation) Figure 4-44. Comparison of injury severity mean s by causes of injuries from falls and slips. 1.62 (.70) 1.60 (.73) 1.52 (.68) 1.51 (.69) 1.49 (.69) 1.47 (.62) 1.45 (.65) 1.39 (.62) 1.38 (.63) 1.251.301.351.401.451.501.551.601.65 On ice or snow (n = 586) Other NOC (n = 1108) From same level (n = 1537) From liquid or grease spills (n = 130) Slip (no fall) (n = 338) On stairs (n = 326) Into openings (n = 307) From different level (n = 1384) From ladder or scaffolding (n = 1371) Injury Severity Mean (Standard Deviation) Figure 445. Differences of injury severity mean s between causes of injury from falls and slips.

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153 Motor Vehicle Information regarding the speci fic cause of injury associat ed with injuries involving a motor vehicle was provided for 414 workers. Table 430 shows the distribution of injuries for the four specific cause classifications associated with injuries due to motor vehicles. Events which involved a collision with another vehicle comprised over half of motor vehicle related injuries (n = 220). Injuries from upset of a motor vehicle account for around 13% of the motor vehicle injuries (n = 53). Less than 8% of the motor vehicle in juries were associated with a collision with a fixed object (n = 33). The results of the Levene test for homogeneity of variances of injury severity scores for the four cause categories for motor vehicle related injuries allowed for the assumption of equal variance, L (3, 404) = 1.06, p >.30. A subsequent ANOVA of the injury severity means was used to identify possible differences in injury sever ity means between the four motor vehicle cause groups. The results of this test showed no signi ficant differences of injury severity means between the groups, F (3, 404) = 1.66, p >.30. Table 430. Causes of injuries involving a motor vehicle. Cause of injury Number of injuries % Cumulative % Collision with another vehicle 220 53.14% 53.14% Other NOC 108 26.09% 79.23% Vehicle upset 53 12.80% 92.03% Collision with a fixed object 33 7.97% 100.00% Total 414 100.00% The Tukeys b range test was still conducted in order to rank, in descending order, the four motor vehicle cause groups according to their respective injury severity means (see Figure 446). Collisions with fixed objects had the highest injury severity mean ( = 1.58), followed by collisions with another vehicle ( = 1.55), ve hicle upsets ( = 1.47), and other motor vehicle incidences not otherwise classified ( = 1.41). Similar to the ANOVA statistic, the Tukeys b

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154 range test also showed no significant differences of severity means between any of the motor vehicle cause categories at p 0.05. 1.41(.70) 1.47 (.58) 1.55 (.77) 1.58 (.66) 1.301.351.401.451.501.551.60 Other miscellaneous, NOC (n = 107) Vehicle upset (n = 51) Collision with another vehicle (n = 217) Collision with a fixed object (n = 33) Injury Severity Mean (Standard Deviation) Figure 446. Comparison of injury severity means by causes of injuries involving a motor vehicle. Strain The specific cause of strain related injuri es was provided for 12,324 workers. Table 431 shows the distribution of injuries for those activities or motions which resulted in a strain injury. Comprising over 30% of the strain related injuries, lifting (n = 3,840) had the highest frequency among strain related injuries. Pushing or pulli ng motions (n = 1,482), and climbing, walking or running activities (n = 1,440) comb ined to generate almost 15% of the strain related injuries. Activities involving holding or carry ing an object (n = 739), the use of a hand tool or machine (n = 638), or a twisting motion (n = 626), combined to account for over 16% of strain related injuries. Kneeling or bending activities (n = 566), along with activit ies requiring repetitive motion (n = 467) or reaching (n = 250), were a ttributable to over 10% of the injuries from straining. Jumping (n = 133) and eith er wielding (i.e., the handling of a tool such as an axe or a bull float) or throwing (n = 53) motions combin ed for less than 2% of all strain injuries.

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155 Table 431. Causes of strain injuries. Cause of injury Number of injuries % Cumulative % Lifting 3,84031.16% 31.16% Other NOC 2,09016.96% 48.12% Pushing or pulling 1,48212.03% 60.14% Climbing, walking, running 1,44011.68% 71.83% Holding or carrying 7396.00% 77.83% Hand tool or machine in use 6385.18% 83.00% Twisting 6265.08% 88.08% Kneeling and/or bending 5664.59% 92.67% Repetitive motion 4673.79% 96.46% Reaching 2502.03% 98.49% Jumping 1331.08% 99.57% Wielding or throwing 530.43% 100.00% Total 12,324100.00% The results of the Levene test for homogeneity of variance of injury severity scores for the twelve Cause of injury classifications for strain related activities did not support the assumption of equal variances of injury sever ity scores for the cause groups, L (11, 12,169) = 2.92, p .001. Without this assumption, a Welch robust test of equality of injury severity means showed that at least one of the straining activit ies had a significantly different injury severity mean than at least one other activity, F (11, 1,181.39) = 5.65, p .001. In order to both rank the activ ities with respect to their i ndividual injury severity means and detect specific differences in severity means between the activ ities, the Tukeys b range test was conducted (see Figure 447 and Figure 448). Strain injuries resulting from repetitive motions had the highest injury severity mean ( = 1.65), followed by strains from jumping ( = 1.52), holding or carrying an object ( = 1.47), wielding or throwing an object ( = 1.46), kneeling or bending ( = 1.44), and twisting motions ( = 1.44).

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156 A further interpretation of the Tukeys b the re sults showed that stra in injuries caused by repetitive motions had a significantly larger injury severity mean than all of the remaining cause categories for strain injuries, except strain injuries caused by jumping (see Figure 448). 1.65 (.65) 1.52 (.69) 1.47 (.64) 1.46 (.73) 1.44 (.64) 1.44 (.63) 1.44 (.62) 1.43 (.62) 1.42 (.63) 1.41 (.61) 1.41 (.61) 1.40 (.60) 1.251.301.351.401.451.501.551.601.651.70 Hand tool or machine in use (n = 625) Other miscellaneous, noc (n = 2066) Climbing, walking and/or running (n = 1427) Pushing or pulling (n = 1461) Reaching (n = 247) Lifting (n = 3794) Twisting (n = 621) Kneeling and/or bending (n = 562) Wielding or throwing (n = 52) Holding or carrying (n = 734) Jumping (n = 129) Repetitive motion (n = 463) Inury Severity Mean (Standard Deviation) Figure 447. Comparison of injury severi ty means by causes of strain injuries. 1.65 (.65) 1.52 (.69) 1.47 (.64) 1.46 (.73) 1.44 (.64) 1.44 (.63) 1.44 (.62) 1.43 (.62) 1.42 (.63) 1.41 (.61) 1.41 (.61) 1.40 (.60) 1.251.301.351.401.451.501.551.601.651.70 Hand tool or machine in use (n = 625) Other miscellaneous, noc (n = 2066) Climbing, walking and/or running (n = 1427) Pushing or pulling (n = 1461) Reaching (n = 247) Lifting (n = 3794) Twisting (n = 621) Kneeling and/or bending (n = 562) Wielding or throwing (n = 52) Holding or carrying (n = 734) Jumping (n = 129) Repetitive motion (n = 463) Inury Severity Mean (Standard Deviation) Figure 448. Differences of injury severity means between causes of strain injuries.

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157 Striking Against or Stepping On Information regarding the sp ecific cause of injuries wa s provided for 2,942 workers who were injured when they struck against or ste pped on an object. Of the five possible causes, striking against or stepping on some type of st ationary object comprised over 30% (n = 1,072) of these injuries (see Table 432). This was follo wed by, in descending order, being struck by or stepping on an object being lifted or handled ( 13.87%, n = 408), a sharp object (10.30%, n = 303), and the moving parts of a machine (7.92%, n = 233). Table 432. Causes of striking against and stepping on injuries. Cause of injury Number of injuries % Cumulative % Stationary object 1,07236.44% 36.44% Other NOC 92631.48% 67.92% Object being lifted of handled 40813.87% 81.78% Sharp object 30310.30% 92.08% Moving parts of machine 2337.92% 100.00% Total 2,942100.00% The results of the Levene test for homogeneity of variance of injury severity scores for the five cause classifications for inju ries associated with Striking against or stepping on could not support the assumption of equal varian ces of injury severity scores for the five Cause of injury groups, L (4, 2,889) = 46.55, p < .001. A subsequent Welch robust test of equality of injury severity means showed that at least one of the striking against or steppi ng on classifications had a significantly different injury severity mean than at least one of the othe r classifications, F (4, 877.55) = 16.91, p < 0.001. This was confirmed by the results of the Tukeys b range test. A Tukeys b range test was conducted to assess the severity of injuries from specific conditions when the worker experienced the inju ry while Striking Against or Stepping On a particular object (see Figure 449). The most seve re of these injuries was attributable to striking against the moving parts of a m achine ( = 1.48). This was followed, in descending order, by injuries caused by striking agai nst or stepping on an object being lifted or handled by the injured

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158 worker or another worker ( = 1.27), a stationary object ( = 1.27), other objects NOC ( = 1.25), and striking against or ste pping on a sharp object ( = 1.11). 1.48 (.75) 1.27 (.57) 1.27 (.53) 1.25 (.53) 1.11 (.36) 0.000.200.400.600.801.001.201.401.60 Sharp object (n = 299) Other miscellaneous, NOC (n = 912) Stationary object (n = 1058) Object being lifted or handled (n = 397) Moving parts of machine (n = 228) Injury Severity Mean (Standard Deviation) Figure 449. Comparison of injury severity means by causes of injuries from striking against or stepping on. Figure 450 shows the specific differences of injury severity means between the five discrete causes of striking against or stepping on injuries. Injuri es caused by striking against or stepping on moving parts of a machine had a sign ificantly greater injury severity mean, at p 0.05, than all of the other injury cause categories. Injuries caused by striking against or stepping on objects being lifted or handled, stationary obj ects, and other miscellaneous objects NOC, each had an injury severity mean sign ificantly greater than that for in juries caused by striking against or stepping on a sharp object. 1.48 (.75) 1.27 (.57) 1.27 (.53) 1.25 (.53) 1.11 (.36) 0.000.200.400.600.801.001.201.401.60 Sharp object (n = 299) Other miscellaneous, NOC (n = 912) Stationary object (n = 1058) Object being lifted or handled (n = 397) Moving parts of machine (n = 228) Injury Severity Mean (Standard Deviation) Figure 450. Differences of injury severity mean s between causes of striki ng against or stepping on injuries.

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159 Struck By The specific cause of struck by injuries wa s provided for 6,008 workers. Table 433 shows the distribution of injuries for those objects whic h resulted in a Struck by injury. Over 70% of the Struck by injuries were attr ibuted to either an object being lifted or handled (n = 2,111) or a falling or flying object (n = 2,218) Being struck by a fellow worker was the least frequent of struck by injuries; however it wa s shown to be the third most se vere type of struck by injury experienced by workers. The results of the Levene test for homogeneity of variance of injury severity scores for the seven causes of Struck by inju ries supported the assumption of equal variance, L (6, 5,884) = 27.03, p .01. A subsequent Welch test of equality of injury severity means for the cause categories for struck by injuries showed that at least one of the Struck by groups had a significantly different injury severity m ean than another group, F (6, 675.16) = 12.68, p < .001. Table 433. Causes of struck by injuries. Cause of injury Number of injuries % Cumulative % Falling or flying object 2,21836.92% 36.92% Object being lifted or handled 2,11135.14% 72.06% Hand tool of machine in use 90515.06% 87.12% Object handled by others 2624.36% 91.48% Motor vehicle 2043.40% 94.88% Other NOC 2003.33% 98.20% Co-workers 1081.80% 100.00% Total 6,008100.00% A Tukeys b range test was conducted to assess the severity of injuries of specific conditions identified when the worker experien ced an injury due to being Struck By a particular object. The results of the Tukeys b test confirmed that there was a significant difference of injury severity means, at p 0.05, between the seven st ruck by cause groups. The subsequent ranking of the specific ca uses of struck by injuries is shown in Figure 451. Injuries

PAGE 160

160 caused by being struck by a motor vehicle had the highest injury severity mean, = 1.69 Injuries caused by being struck by objects NOC ranked second ( = 1.48), followed by being struck by a fellow worker ( = 1.46), a falling or flying object ( = 1.31), objects being handled by others ( = 1.31), and objects bein g lifted or handled by the injured worker or other worker ( = 1.28). Struck by injuries involvi ng hand tools or the use of a machine had the lowest injury severity mean ( = 1.23). A subsequent examination of Figure 451 showed that injuries caused by being struck by a motor vehicle had a significantly higher injury severity mean, at p 0.05, than all of the remaining categories of struck by injuries (see Fi gure 452). Injuries resulting from being struck by NOC objects, and fellow workers each had an in jury severity mean significantly higher, at p 0.05, than injuries which were caused by being struck by a falling or flying object, an object being handled by another person, an object being lifted or handled by the injured worker or coworker another individual, and ha nd tools or machinery being used. 1.23 (.51) 1.28 (.56) 1.31 (.58) 1.31 (.59) 1.46 (.65) 1.48 (.67) 1.69 (.90)0.000.200.400.600.801.001.201.401.601.80Hand Tool or Machine in Use (n = 887) Object Being Lifted or Handled (n = 2074) Object Handled by Others (n = 254) Falling or Flying Object (n = 2171) Fellow Worker (n = 106) Other NOC (n = 199) Motor Vehicle (n = 200) Injury Severity Mean (Standard Deviation) Figure 451. Comparison of injury severity means by causes of struck by injuries.

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161 1.23 (.51) 1.28 (.56) 1.31 (.58) 1.31 (.59) 1.46 (.65) 1.48 (.67) 1.69 (.90) 0.000.200.400.600.801.001.201.401.601.80 Hand Tool or Machine in Use (n = 887) Object Being Lifted or Handled (n = 2074) Object Handled by Others (n = 254) Falling or Flying Object (n = 2171) Fellow Worker (n = 106) Other NOC (n = 199) Motor Vehicle (n = 200) Injury Severity Mean (Standard Deviation) Figure 452. Differences of injury severity means between causes of struck by injuries. Agent of injury The Agent of Injury was defined as that sp ecific physical item that was identified as the actual person or object that was involved in the in jury. The agent of injury directly contributed to the injury. Eighteen General Agent of injury categories were identified. Each of these categories was further delineated by associated Agent of Injury classifications. General Agent of injury Information regarding General Agent of In jury was provided for 30,307 worker injuries. Table 434 shows the distribution of injuries by their respective general agent of injury classifications. The five leading General Agent of injury groups associated with injuries were materials (n = 13,971, 46.10%), tool(s) (n = 3,421, 11.29%), machinery (n = 2,326, 7.67), ladders/scaffolds (2,195, 7.24%), and change in surface texture (n = 1,790, 5.91%). Potholes (n = 84, 0.28%), manholes (n = 78, 0.26%), power lines or poles (n = 75, 0.25%), building material components (n = 46, 0.15%), and lead (n = 8, 0.0 3%) comprised less than two % of the total recorded injuries.

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162 The results of the Levene test for homogeneity of variance of injury severity scores for the eighteen General Agent of Injury classificat ions did not support the assumption of equal variance, L (17, 29,809) = 110.25, p .001. A subsequent Welch robust test of equality of injury severity means showed that at least one of the General Agent of injury classifications had a significantly different injury severity mean than another of these clas sifications, F (17, 486.88) = 47.65, p < .001. This was confirmed by the results of the Tukeys b range test, significant at p 0.05 (see Figure 453). Table 434. General agent of injury. General agent of injury Number of injuries % Cumulative % Material 13,97146.10% 46.10% Tool 3,42111.29% 57.39% Machinery 2,3267.67% 65.06% Ladder/scaffold 2,1957.24% 72.31% Change in surface texture 1,7905.91% 78.21% Vehicle 1,4174.68% 82.89% Person 1,1363.75% 86.64% Organism 8542.82% 89.45% Chemical 8262.73% 92.18% Weather conditions 7542.49% 94.67% Sharp object NOC 5701.88% 96.55% Furniture 5221.72% 98.27% Weighted item NOC 2340.77% 99.04% Potholes 840.28% 99.32% Manhole 780.26% 99.58% Power lines or poles 750.25% 99.82% Building exposure 460.15% 99.98% Lead 80.03% 100.00% Total 30,307100.00% Among the General Agent of In jury categories, injuries involving a vehicle had the highest injury severity mean ( = 1.52), followed closely by exposur e to lead ( = 1.50), ladders or scaffolds ( = 1.50), and weighted items ( = 1.48). Injury events br ought on by a change in surface texture ranked fifth in terms of injury severity ( = 1.46). General agents of injury, ranking from 6th through 18th by injury severity mean were as follows; another person ( = 1.43),

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163 machinery ( = 1.40), power lines or poles ( = 1.39), weather conditions ( = 1.38), furniture or furnishings ( = 1.36), manholes ( = 1.35), potho les ( = 1.33), buildi ng exposure ( = 1.32), tools ( = 1.25), chemicals ( = 1.23), sharp objects NOC ( = 1.16), and organisms ( = 1.15). 1.52 (.74) 1.50 (.53) 1.50 (.65) 1.48 (.66) 1.45 (.66) 1.43 (.67) 1.40 (.69) 1.39 (.59) 1.38 (.63) 1.36 (.61) 1.35 (.66) 1.33 (.55) 1.32 (.57) 1.26 (.54) 1.25 (.53) 1.23 (.51) 1.16 (.45) 1.15 (.45) 0.000.200.400.600.801.001.201.401.60 Organism (n = 843) Sharp object noc (n = 564) Chemical (n = 811) Tool (n = 3365) Building material noc (n = 13726) Building exposure (n = 41) Potholes (n = 80) Manhole (n = 78) Furniture (n = 518) Weather conditions (n = 748) Power lines or poles (n = 75) Machinery (n = 2291) Person (n = 1120) Surface texture change (n = 1769) Weighted item (n = 231) Ladder/scaffold (n = 2173) Lead (n = 8) Vehicle (n = 1386) Injury Severity Mean (Standard Deviation) Figure 453. Comparison of injury severity means by general agents of injury. Specific injury severity mean differences, significant at p 0.05, between the General Agent of injury classifications were discerne d from Figure 453 and displayed in Figure 454. Injuries for which the general agen t of injury was identified as a vehicle, lead exposure, a ladder or scaffold, or a weighted item each had a significantly higher injury severity mean than injuries from sharp objects NOC and injuries from contact with some type of organism other than another person. Injuries involving a change in su rface texture had a significantly greater injury severity mean, at p 0.05, than injuries resulting fr om contact with an organism.

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164 1.52 (.74) 1.50 (.53) 1.50 (.65) 1.48 (.66) 1.45 (.66) 1.43 (.67) 1.40 (.69) 1.39 (.59) 1.38 (.63) 1.36 (.61) 1.35 (.66) 1.33 (.55) 1.32 (.57) 1.26 (.54) 1.25 (.53) 1.23 (.51) 1.16 (.45) 1.15 (.45) 0.000.200.400.600. 801.001.201.401.60 Organism (n = 843) Sharp object noc (n = 564) Chemical (n = 811) Tool (n = 3365) Building material noc (n = 13726) Building exposure (n = 41) Potholes (n = 80) Manhole (n = 78) Furniture (n = 518) Weather conditions (n = 748) Power lines or poles (n = 75) Machinery (n = 2291) Person (n = 1120) Surface texture change (n = 1769) Weighted item (n = 231) Ladder/scaffold (n = 2173) Lead (n = 8) Vehicle (n = 1386) Injury Severity Mean (Standard Deviation) Figure 454. Differences of injury severity means between genera l agents of injury. Building Exposure The specific agent leading to injuries from building exposures was identified for 46 such injuries. Table 435 shows the distribution of Building Exposure injuries by specific Agent of Injury categories. Informa tion regarding this category was provided for 46 workers. Over 90% (n = 43) of these injuries were attributed some kind of construction product as the specific building exposure agent of in jury. Carbon monoxide emission from unidentified building

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165 components was attributed to two of the injuries. In one reported case, Sick Building was use to describe the specific agent of injury. Table 435. Agent of buildi ng exposure related injuries. Agent of injury Number of injuries % Cumulative % Construction products 4393.48% 93.48% Carbon monoxide 24.35% 97.83% Sick building 12.17% 100.00% Total 46100.00% A comparison of injury severity means between each of these buildi ng exposure Agent of injury classifications showed c onstruction products with the highest injury severity mean ( = 1.34). However, due to the low frequencies for the remaining two Agent of Injury classifications, statistically significant differe nces between the severity means could not be discerned. Collectively these three classificati ons had an injury severity mean of = 1.32, ranking 12th out of the eighteen General ag ent of injury classifications. Chemical Information pertaining to chemical related in juries was provided for 826 worker injuries. Over 76% of the chemical related injuries were at tributed to some kind of acid (n = 629) as the specific Agent of Injury (see Table 436). Chem ical agents attributable to the presence of some type of fume accounted for over 20% of th e reported chemical rela ted injuries. Chemical exposure of fumes was broken out in to three Agent of Injury subclassifications: fumes of hard metals (n = 45, 5.45%) including those produced by welding operations, fumes (unrelated to lead) of coatings, and paint products (n = 8, 0.97%). Smoke of a fire comprised almost 4% (n = 30) of the injuries associat ed with a chemical agent. Possible differences of injury severity means between the five chemical agent of injury classifications were examined. A Levene test of homogeneity of variances of injury severity scores allowed for an assumption of equal variances of injury severity scores for the five Agent

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166 of injury classifications L (4, 806) = .71, p > 0.05. Subsequently, the ANOVA test of equality of means was conducted and the results showed th e lack of any significant differences between the injury severity means for the chemical ag ent of injury categorie s, F (4, 805) = 0.65, p > 0.60. Table 436. Agent of chemical related injuries. Agent of injury Number of injuries % Cumulative % Acid 62976.15% 76.15% Fumes NOC 11413.80% 89.95% Fumes from hard metals (incl. Welding) 455.45% 95.40% Smoke of Fire 303.63% 99.03% Fumes from coatings, paint (Not Lead) 80.97% 100.00% Total 826100.00% Even though no significant differences were found between the inju ry severity means among the chemical Agent of Injury classifications, the Tukeys b range test was still conducted in order to rank, in desc ending order of injury severity means, the five classifications (see Figure 455). Chemi cal fumes from coatings or paint products showed the highest injury severity mean ( = 1.25). Chemical injuries fr om acids ( = 1.24) and smoke ( = 1.23) ranked second and third, respectively. Ch emical exposure from hard metal fumes ( = 1.20) and from fumes not otherwise classified ( =1.20) show ed the lowest injury severity mean levels. 1.20 (45) 1.20 (.46) 1.23 (.50) 1.24 (.53) 1.25 (.46) 1.10 1.20 1.30 Fumes NOC (n = 110) Fumes Hard Metals, Including Welding (n = 45) Smoke (n = 30) Acid (n = 618) Fumes Coatings, Paint (Not Lead) (n = 8) Injury Severity Mean Figure 455. Comparison of injury severity means by agent of chemical related injuries. A comparison of the injury severity mean s was conducted for the Agent of injury categories for furniture related injuries (see Tabl e 437). The Levene test for homogeneity of

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167 variances allowed for the assumption of equal variances, L (2, 514) = 0.59, p > .50. Subsequently, the ANOVA test of injury severity means for the Agent of Injury categories for furniture related injuries showed a lack of significant difference of injury severity means between the three groups, F (2, 514) = 0.97, p > 0.40. This was confirmed by the results of the Tukeys b range test. Table 437. Agent of furniture or furnishings related injuries Agent of injury Number of injuries % Cumulative % Fixtures, furnishings 51398.46% 98.46% Commodes 40.77% 99.23% Display items 40.77% 100.00% Total 521100.00% The Tukeys b range test for means was perfor med in order to rank the three categories by their respective injury se verity means. Figure 456 shows th at, among furniture related injuries, commodes had the highest injury severity means ( = 1.75), followed by fixtures and furnishings ( = 1.36). Display items showed the lowest injury severity mean level ( = 1.25). 1.75 (.50) 1.36 (.61) 1.25 (.50) 0.000.250.500.751.001.251.501.752.00Display Items (n = 4) Fixtures, Furnishings (n = 509) Commode (n = 4) Injury Severity Mean (Standard Deviation) Figure 456. Comparison of injury severity mean s by agent of furniture or furnishings related injuries. Lead Information regarding injuries related to l ead containing products was provide for eight worker injuries. Five of the eight Agent of Injury categories associated with lead-related injuries involved the handling of some form type of paint product (see Table 438).

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168 Table 438. Agent of lead related injuries. Agent of injury Number of injuries % Cumulative % Paint products 562.50% 62.50% Other NOC 337.50%100.00% Total 8100.00% To compare the injury severity means betw een the two lead categories an independent samples t-test was conducted (see Figure 457). The results of the Levene test for equality of injury scores variances allowed for the a ssumption of equal variances, L (1, 6) = 0.74, p > 0.70. The results of the independent samples t-test showed that injuries associated with lead of paint products had a higher injury seve rity mean ( = 1.60) than le ad in sources not otherwise classified ( = 1.33); this differe nce was not shown to be statis tically signific ant, t (6) = 0.66, p > .50. 1.33 (0.55) 1.60 (0.58) 0.000.501.001.502.00 Lead NOC (n = 3) Lead from paint products (n = 5) Injury Severity Mean (Standard Deviation) Figure 457. Comparison of injury severity means by agent of lead related injuries. Machinery Information regarding machinery related inju ries was provided for 2,326 workers injuries. Table 439 shows, injuries for which Machiner y was identified as the General agent of Injury as distributed ov er eleven Agent of injury categor ies. The majority of incidents for which a specific machinery item was identified we re associated with some form of electrical apparatus (n = 333, 14.32%). Together, mainte nance equipment (n = 122, 5.25%) and metal working machinery or equipment (n = 131, 5.63%) accounted for almost 11% of the machinery related injuries. Injuries invol ving turnstiles (n = 7, 0.03%), wood working equipment (n = 9, 0.39%), pumps (n = 19, 0.82%), conveyors (n = 27, 1.16%), belts, pulleys, gears or shafts (n =

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169 27, 1.16%), hoisting equipment (n = 66, 2.84%) a nd furnace or heating equipment (69, 2.97%) accounted for less than 10 % of all the machinery related injuries. The results of the Levene test for homogeneity of injury severity score variances did not allow the assumption equal variances between th e 11 agents of injury for machinery related injuries. L (10, 2,280) = 6.16, p < .001. The subsequent Welch test for equality of injury severity means the results showed that at least one of th ese categories was signifi cantly different from another, F (10, 83.47) = 2.94, p < .01 This result was not conf irmed by the subsequent Tukeys b range test. Table 439. Agent of mach inery related injuries. Agent of injury Number of injuries % Cumulative % Other NOC 1,51665.18% 65.18% Electrical apparatus 33314.32% 79.50% Metal working 1315.63% 85.13% Maintenance equipment 1225.25% 90.37% Furnace or heating equipment 692.97% 93.34% Hoisting apparatus 662.84% 96.18% Belts, pulleys, gears, shafts 271.16% 97.34% Conveyors 271.16% 98.50% Pumps 190.82% 99.32% Wood working 90.39% 99.70% Turnstile 70.30% 100.00% Total 2,326100.00% The Tukeys b range test was conducted to a ssess the severity of injuries of specific Agent of Injury categories for machinery rela ted injuries. No significant difference of injury severity means, at p 0.05, was detected betw een the Agent of Inju ry categories identified with machinery related injuries. The ranking of these categories (see Figu re 458) shows that injuries from conveyor type machinery generated the highest injury severity mean ( = 1.67) among the machinery related injuries, and injuries involving turnstiles were associated with the lowest injury severity mean ( = 1.14).

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170 1.14 (.38) 1.19 (.43) 1.27 (.54) 1.35 (.56) 1.38 (.52) 1.42 (.72) 1.42 (.70) 1.42 (.77) 1.45 (.73) 1.48 (.64) 1.67 (1.00) 0.000.200.400.600.801.001.201.401.601.80 Turnstile (n = 7) Furnace or Heating Equipment (n = 69) Metal Working (n = 129) Maintenance Equipment (n = 121) Wood Working (n = 8) Electrical Apparatus (n = 327) Not Otherwise Classified (n = 1493) Pumps (n = 19) Hoisting Apparatus (n = 64) Belts, Pulleys, Gears, Shafts (n = 27) Conveyors (n = 27) Injury Severity Mean (Standard Deviation) Figure 458. Comparison of injury severity means by agent of machinery related injuries. Manholes Injuries associated with Ma nholes accounted for less than 1% (n = 78) of the injuries recorded for this General Agent of Injury vari able. No Agent of Injury sub-classifications were identifiable from the data for manhole injuri es. The injury severity mean ( = 1.35) for manhole injuries ranked eleventh among the Gener al Agent of injury ca tegories. It was not significantly different, at p 0.05, than any of the other classifications. Material The distribution of injuries for material related injuries are displayed in Table 440. Information was provided for 13,971 worker injuri es. The majority of the material related injuries were directly associ ated with wire or metal material (n = 5,077, 36.34%). Piping (n = 1,867) and wood material (n = 1,673) each account ed for over 11% of the material related injuries. Rock or stone materials (n = 1,117) made up eight % of material related injuries. Nails (n = 896), boxes, barrels, and other containers or packages (n = 893), accounted for over 12 % of

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171 the material related injuries. The remaining 13 Agent of Injury categories for material related injuries accounted for less than 6 % of the injuries. Table 440. Agent of injury fo r material related injuries. Agent of injury Number of injuries % Cumulative % Wire or metal 5,07736.34% 36.34% Pipe 1,86713.36% 49.70% Wood 1,67311.97% 61.68% Rock or stone 1,1178.00% 69.67% Foreign matter 1,0657.62% 77.30% Nail 8966.41% 83.71% Boxes, barrells, containers, packages 8936.39% 90.10% Windows, doors 3422.45% 92.55% Scrap materials 2701.93% 94.48% Asbestos 1791.28% 95.76% Glass 1551.11% 96.87% Plastic 910.65% 97.52% Fence 860.62% 98.14% Automotive parts 720.52% 98.65% Garbage cans, bags 720.52% 99.17% Plumbing supplies 470.34% 99.51% Shoes, clothing, apparel 220.16% 99.66% Ceramic 190.14% 99.80% Pulp or Paper 180.13% 99.93% Coal & Petroleum Product(s) 100.07% 100.00% Total 13,971100.00% The Tukeys b range test was c onducted to evaluate possible differences in injury severity means between the Agent of Injury categorie s for materials related injuries. Figure 459 shows the ranking, in descending or der of the injury se verity mean magnitude associated with the Agent of Injury classifications for material s related injuries. Injuri es involving contact with coal or petroleum materials had the highest injury severity m ean ( = 1.60) followed by contact with pulp or paper products ( = 1.56). Boxes, barrels, containe rs or packages had the third highest injury severity mean ( = 1.40), followed by fencing material ( = 1.38), automotive parts ( = 1.33), and rock or stone material ( = 1.33). Materials ranking between seventh and ninth, with an injury severity mean of = 1.31, included windows and doors, wood material, and

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172 asbestos material. Plumbing materials ranked 10th ( = 1.30), followed by shoes, clothing and apparel ( = 1.30), and plastic materials ( = 1.30). The bottom eight materials include ceramic materials ( = 1.29), pipe ( = 1.28), garbage cans or bags ( = 1.27), gl ass materials ( = 1.25), wire or metal materials ( = 1.24), scrap material s ( = 1.21), nails ( = 1.11), and materials not otherwise classified ( = 1.10). 1.60 (.97) 1.56 (.70) 1.40 (.62) 1.38 (.67) 1.33 (.61) 1.33 (.59) 1.31 (.60) 1.31 (.57) 1.31 (.64) 1.30 (.55) 1.30 (.47) 1.30 (.55) 1.29 (.59) 1.28 (.54) 1.27 (.48) 1.25 (.52) 1.24 (.53) 1.21 (.50) 1.11 (.36) 1.10 (.38) 0.000.200.400.600.801.001.201.401.601.80 Material NOC (n = 1036) Nail (n = 884) Scrap materials (n = 26) Wire or metal (n = 4983) Glass (n = 151) Garbage cans, bags (n = 71) Pipe (n = 1844) Ceramic (n = 17) Plastic (n = 91) Shoes, clothing, apparel (n = 20) Plumbing (n = 46) Asbestos (n = 175) Wood (n = 1647) Windows, doors (n = 334) Rock or stone (n = 1098) Automotive parts (n = 70) Fence (n = 85) Boxes, barrels, containers, packages (n = 878) Pulp or paper (n = 18) Coal & petroleum product(s) (n = 10) Injury Severity Mean (Standard Deviation) Figure 459. Comparison injury severity mean s by agent of material related injuries. Materials which had significantly diffe rent injury severity means, at p 0.05, from other material categories were discerned from Figure 459 and displayed in Figure 460. Injuries involving coal and/or petr oleum materials had a significantly gr eater injury severity mean ( =

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173 1.60), at p 0.05, than injuries directly associated with wire or metal materials ( = 1.24), scrap materials ( = 1.21), nails ( = 1.11), and other ma terial not otherwise classified ( = 1.10). Injuries from pulp or paper materials showed a significantly greater sever ity mean ( = 1.56), at p 0.05, than injuries from nails and other mate rials not otherwise classified. No other significant differences of injury severity means were detected, at p 0.05, between the Agent of injury groups for materials related injuries 1.60 (.97) 1.56 (.70) 1.40 (.62) 1.38 (.67) 1.33 (.61) 1.33 (.59) 1.31 (.60) 1.31 (.57) 1.31 (.64) 1.30 (.55) 1.30 (.47) 1.30 (.55) 1.29 (.59) 1.28 (.54) 1.27 (.48) 1.25 (.52) 1.24 (.53) 1.21 (.50) 1.11 (.36) 1.10 (.38) 0.000.200.400.600.801.001.201.401.601.80 Material NOC (n = 1036) Nail (n = 884) Scrap materials (n = 26) Wire or metal (n = 4983) Glass (n = 151) Garbage cans, bags (n = 71) Pipe (n = 1844) Ceramic (n = 17) Plastic (n = 91) Shoes, clothing, apparel (n = 20) Plumbing (n = 46) Asbestos (n = 175) Wood (n = 1647) Windows, doors (n = 334) Rock or stone (n = 1098) Automotive parts (n = 70) Fence (n = 85) Boxes, barrels, containers, packages (n = 878) Pulp or paper (n = 18) Coal & petroleum product(s) (n = 10) Injury Severity Mean (Standard Deviation) Figure 460. Differences of injury severity mean s between agents of material related injuries. Organism Information regarding injuries directly asso ciated with contact with an organism was provided for 854 workers. Injuries involving an insect comprised al most half (n = 424) of the

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174 injuries attributed to contact with some type of organism (see Table 441). Over 23% of the organism related injuries were associated with contact with a plant (n = 200, 23.42%). Contact with either an animal (n = 149, 17.45%) or animal or insect not otherwise classified (n = 64, 7.49%) comprised almost 25% of injuries resulti ng from contact with an organism. The least common type of organism related injury organi sm was direct contact with bacteria (n = 17, 49.65%). Table 441. Agent of animal or insect related injuries. Agent of injury Number of injuries % Cumulative % Insect 42449.65% 49.65% Plant 20023.42% 73.07% Animal 14917.45% 90.52% Animal or insect NOC 647.49% 98.01% Bacteria 171.99% 100.00% Total 854100.00% Equal variances of the injury se verity means for the five Age nt of injury classifications for organism related injuries could not be assumed, L (4, 838) = 12.21, p < .001. The results of a Welch test for equality of injury severity mean s suggested that at leas t one of the Agent of Injury groups had a significantly different seve rity mean than another classification, F (4, 95.35) = 3.19, p < .02. This was confirmed by the subsequent Tukeys b range test. The results of the Tukeys b range test for in jury severity means for the five Organism classifications are illustrated in Figure 461. Despite being the least common of the injury classifications for injuries associated with expos ure to an organism, bacteria related injuries showed the highest injury severi ty mean ( = 1.35). Injuries for which the agent of injury was specifically identified as an animal had the se cond highest injury seve rity mean ( = 1.22), followed by a plant ( = 1.19), and ei ther an animal or an insect ( = 1.11). Injuries of contact with an insect had the lowest injury severity mean ( = 1.10) among injuries for which contact with an organism was identified as the general agent of injury.

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175 1.35 (.61) 1.22 (.49) 1.19 (.57) 1.11 (.36) 1.10 (.37) 0.000.200.400.600.801.001.201.401.60 Insect (n = 419) Animal or Insect (n = 63) Plant (n = 196) Animal (n = 148) Bacteria (n = 17) Injury Severity Mean (Standard Deviation) Figure 461. Comparison of injury severity means by agent of organi sm related injuries. The injury severity mean for bacteria re lated injuries was si gnificantly greater, at p 0.05, than injuries associated with either animal or insect ( = 1.11) and those injuries for which an insect ( = 1.10) was identified as the orga nism agent of injury (see Figure 462). 1.35 (.61) 1.22 (.49) 1.19 (.57) 1.11 (.36) 1.10 (.37) 0.000.200.400.600.801.001.201.401.60 Insect (n = 419) Animal or Insect (n = 63) Plant (n = 196) Animal (n = 148) Bacteria (n = 17) Injury Severity Mean (Standard Deviation) Figure 462. Differences of severity means be tween agents of organism related injuries. Person The distribution of injuries for the four agent of injury classi fications associated with those injuries in which a Person was identified as the General agent of injury is displayed in Table 442. Information regarding Person related injuries was provided for 1,136 worker injuries. Contact with a co-worker comprised over 80% (n = 948) of these injuries. Contact with maintenance personnel (n = 11, 0.97%), medical personnel (n = 42, 3.70%), and other persons not otherwise classified (n = 135, 11.88%), as an aggregate, accounted for less than 17% of the injuries associated with contact with another person. The results of the Levene test for homogeneity of the injury severity scores for the four Person agent of injury categories allowed for the assumption of equal variances of injury

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176 severity scores for the four Agent of injury classifications for injuries associated with direct contact with another person, L (3, 1,116) = 2.41, p > .06. The results of the subsequent ANOVA did not show any significant difference between th e four Agent of Injury groups, F (3, 1,116) = 1.41, p > 0.60. This result was confirme d by the Tukeys b range test. Table 442. Agent of injuri es related to a person. Agent of injury Number of injuries % Cumulative % Co-worker 94883.45% 83.45% Person NOC 13511.88% 95.33% Medical personnel 423.70% 99.03% Maintenance personnel 110.97% 100.00% Total 1,136100.00% The Tukeys b range test was conducted to gene rate the rankings, in descending order of injury severity means, for the four Agent of In jury groups for injuries associated with contact with another person (see Figure 463). Injuries resulting from c ontact with medical personnel ( = 1.48) and co-workers ( = 1.44) ranked first and second, respectivel y, in terms of their injury severity means. Contact with maintenance personne l showed the lowest injury severity mean ( = 1.18), among the four categories. 1.18 (.40) 1.43 (.67) 1.44 (.67) 1.48 (.83) 0.00 0.50 1.00 1.50 Maintenance Personnel (n = 11) Other Person, NOC (n = 132) Co-Worker (n = 935) Medical Personnel (n = 42) Injury Severity Mean (Standard Deviation) Figure 463. Comparison of injury severity means by agent of person related injuries. Potholes Injuries associated with Potholes as the ge neral agent of injury accounted for less than 1% (n = 84) of the injuries recorded for the G eneral agent of injury variable. No Agent of

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177 injury classifications were identifiable from the data for injuries associated with Potholes. The injury severity mean ( = 1.33) for potholes related injuries rank ed twelfth among the General Agent of injury categories. It was not significantly different, at p 0.05, than any of the other General agent of injury. Power Lines or Poles Injuries associated with Power lines or pol es as the general agent of injury accounted for less than 1% (n = 75) of the injuries recorded for the General Agent of Injury variable. No Agent of Injury classifications were identifi ed from the data for Power lines or poles injuries. The injury severity mean ( = 1.39) fo r Power lines or poles injuries ranked eighth among the General agent of injury categorie s. It was not signifi cantly different, at p 0.05, than any of the other General Agent of Injury classifications. Sharp Object Not Otherwise Classified (NOC) Injuries associated with Sharp object NOC as the general agent of injury accounted for approximately 2 % (n = 570) of the injuries recorded for the General Agent of Injury variable. No Agent of Injury classifications were disc ernable from the data for Sharp Object NOC injuries. The injury severity mean ( = 1.16) for Sharp Object NOC injuries ranked seventeenth, out of eighteen, among the General Agent of In jury categories. It was not significantly, different, at p 0.05, than any of the other General Agent of injury classifications. Change in Surface Texture Information regarding injuries resulting from a change in the surface texture of the workers surroundings was provided for 1,790 wo rker injuries. Table 443 shows the distribution of injuries for the four Agent of Injury categorie s for injuries associated with changes in surface texture. No specific contributin g Agent of Injury could be identified for

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178 over 86% (n = 1,547) of the change in surface te xture injuries. Spills from liquids, food or grease (n = 137, 7.65%) and wet floors from cleaning or waxing (n = 100, 5.59%) each comprised over five % of the total number of Change in Surface Texture injury cases. Six cases identified spills or leakage from a tank or vessel (0.34%) as the speci fic Agent of Injury which lead to the change in surface texture. Table 443. Agent of change in surface texture related injuries. Agent of injury Number of injuries % Cumulative % Change in surface texture NOC 1,54786.42%86.42% Spills of liquid, food or grease 1377.65%94.07% Wet floor from cleaning 1005.59%99.66% Spills of a tank or vessel 60.34%100.00% Total 1,790100.00% The Levene test for homogeneity of variances of injury severity scores among the four Change in Surface Texture classifications did no t allow for the assumption of equal variances, L (3, 1,765) = 3.04, p < 0.03. Subsequent the results of the Welch test of equality of injury severity means for the four Agent of Injury classifications for injuries associated with a change in surface texture showed no significant difference between the severity means of the four Agent of Injury categories, F (3, 23.60) = 1.36, p > 0.20. The injury severity means were ranked using the Tukeys b range test (see Figure 464). Among specific agents of loss associated with change in surface texture related injuries those not otherwise classified ( = 1.46), and thse due to a floors wet from cleaning or waxing had the second highest injury severity m ean ( = 1.44). This was followed by spills from food, liquid or grease ( = 1.39). Change in surface texture due to spills or leakage from a tank or vessel showed the lowest severity mean level ( = 1.17) among the four Change in Surface Texture classifications. The results also confirmed the results of the ANOVA by showing no significant injury severity mean differences, at p 0.05, between any of the four categories.

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179 1.17 (.41) 1.39 (.66) 1.44 (.58) 1.46 (.66) 0.000.200.400.600.801.001.201.401.60 Spills or Leakage From a Tank or Vessel (n = 6) Spills of Liquid, Food or Grease (n = 134) Wet Floor From Cleaning or Waxing (n = 98) Change In Surface Texture NOC (n = 1531) Injury Severity Mean (Standard Deviation) Figure 464. Comparison of injury severity mean s by agent of change in surface texture related injuries. Tool Injuries from non-powered hand tools (n = 1,616 ) accounted for almost half of the reported injuries which involved tools (s ee Table 444). Powered hand t ools (n = 1,269) comprised over a third of the tool related injuries Over 15% of the tool related injuries were directly associated with some type of non-powered knife (n = 536). Table 444. Agent of t ool related injuries. Agent of injury Number of injuries % Cumulative % Non-powered hand tools 1,61647.24% 47.24% Powered hand tools 1,26937.09% 84.33% Non-powered knife 53615.67% 100.00% Total 3,421100.00% The results of the Levene test for homogeneity of variances of injury severity scores for the three Tool(s) classifications did not allow fo r an assumption of equal variances of injury severity scores, L (2, 3,362) = 98.07, p .001. The results of a subsequent Welch robust test of equality of injury severity m eans revealed a statistic ally significant difference among the severity means of the three Agent of Injury categories for tool related injuries, F (2, 1,604.67) = 32.66, p .001.

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180 The Tukeys b range test was c onducted, and showed that the most severe of these injuries were attributable to an injury experienced wh ile using a powered hand tool ( = 1.30), followed by a non-powered hand tool ( = 1.25). Use of a non-powered knife had the lowest injury severity mean ( = 1.11) (see Figure 465). 1.30 (.57) 1.25 (.53) 1.11 (.42) 0.901.051.201.35 Non-Powered Knife (n = 531) Non-Powered Hand Tools (n = 1584) Powered Hand Tools (n = 1250) Injury Severity Mean (Standard Deviation) Figure 465. Comparison of injury severity means by agent of tool related injuries. 1.30 (.57) 1.25 (.53) 1.11 (.42) 0.90 1.05 1.20 1.35 Non-Powered Knife (n = 531) Non-Powered Hand Tools (n = 1584) Powered Hand Tools (n = 1250) Injury Severity Mean (Standard Deviation) Figure 466. Difference of injury severity m eans between agents of tool related injuries. There was no significant difference, at p 0.05, of injury severity means between injuries of powered hand tools and non-power ed hand tools (see Figure 466). Injuries associated with the use of a non-powered knife had a signifi cantly lower injury severity mean, at p 0.05, than injuries associated with the us e of either powered or non-powered hand tools (see Figure 466). Vehicle The distribution of injuries for the specific items associated with the Vehicle category of General Agent of injury is displayed in Table 445. Vehicles not otherwise classified

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181 accounted for more than half of the reported injuries (n = 771) wh ich involved a vehicle. Mobile machinery or equipment account for the largest numb er of distinguishable vehicle related injuries (n = 450). Delivery carts, wagons and bicycles (n = 188) accounted for over 13% of the vehicle related injuries. Eight (.56%) vehicle related injuri es were directly associ ated with a golf cart. Table 445. Agent of ve hicle related injuries. Agent of injury Number of injuries % Cumulative % Vehicle NOC 77154.41% 54.41% Mobile machinery/equipment 45031.76% 86.17% Delivery cart. Wagon, or bicycle 18813.27% 99.43% Golf cart 80.56%100.00% Total 1,417100.00% The injury severity means for the four Vehicle categories were compared. Equal variance of injury severity scores was assumed, L (3, 1,382) = 1.97, p > 0.10. This prompted the use of the ANOVA test of equality of injury se verity means for the four Agent of Injury categories for vehicle related injuries. The results of this test indicate d no significant means difference between the four Vehicle groups, F (3, 1,382) = 1.85, p > 0.10. The results of the Tukeys b range test at p 0.05are displayed in Figure 467. Injuries involving some kind of mobile mach inery or equipment showed the highest injury severity mean, ( = 1.53) and injuries involving a golf cart exhib ited the lowest injury se verity mean ( = 1.38) among vehicle related injuries. There were no signi ficant differences of injury severity means between any of the four Agent of injury classifications. 1.38 (.52) 1.41 (.66) 1.53 (.76) 1.55 (.74) 1.251.301.351.401.451.501.551.60 Golf Cart (n = 8) Delivery Cart, Wagon or Bicycle (n = 186) Mobile Machinery/Equipment (n = 436) Vehicle NOC (n = 756) Inury Severity Mean (Standard Deviation) Figure 467. Comparison injury severity means by agent of vehicle related injuries.

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182 Weather Conditions Weather related injuries account ed for 754 of the 30,307 injuries for which General agent of injury were recorded. No Agent of injury classifications were disc ernable of the data for weather related injuries The injury severity mean ( = 1.38) for Weather conditions injuries ranked ninth, out of eighteen, among the General agent of injury categories. It was not significantly, different, at p 0.05, from any of the other G eneral agent of injury classifications. Weighted Item Information regarding the six Agent of injury categories for injuries involving a weighted item was provided for 234 worker inju ries. Table 446 shows that the most common injuries associated with a weighted item involved objects weighing over 150 pounds (n = 56, 23.93%), weighing from 26 to 50 pounds (n = 49, 20.94%), and those weighing up to 25 pounds (n = 45, 19.23%). Less than 25% of weighted it em injuries weighed between 51 and 150 pounds. As a whole, the injury severity mean for in juries associated with a weighted item ranked third (see Figure 453). Weighted item in juries had a significantly higher, at p 0.05, severity mean ( = 1.48) than injuries associated with an exposure to an organism ( = 1.15) and injuries from contact with a sharp object ( = 1.16). Table 446. Agent of injuries related to weighted items. Agent of injury Number of injuries % Cumulative % More than 150 Lbs. 5623.93% 23.93% Of 26 to 50 Lbs. 4920.94% 44.87% Up to 25 Lbs. 4519.23% 64.10% From 76 to 100 Lbs. 3314.10% 78.20% From 51 to 75 Lbs. 3213.68% 91.88% From 101 to 150 Lbs. 198.12%100.00% Total 234100.00%

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183 An assumption of equal variances of injury severity scores was supported for the six Agent of Injury categories for injuries involving a weighted item, L (5,225) = 1.88, p > 0.10. An ANOVA revealed no statistica lly significant difference between the severity means of the six Agent of Injury injuries associated with weighted items, F (5, 225) = 1.44, p >.60). This was confirmed by the results of the Tukeys b range test for inju ry severity means, significant at p 0.05. The Tukeys b test also showed the ranking, in descending order of injury severity mean, of the six Agent of injury groups for injuries involving the handling of weighted items (see Figure 468). Items weighing more than 150 pounds were associated with the most severe of these injuries ( = 1.55), followed by items weighing between 76 and 100 pounds ( = 1.54), 101 to 150 pounds ( = 1.53), and items weighing less than 25 pounds ( = 1.38) were associated with least severe weighted item injuries. 1.55 (.85) 1.55 (.62) 1.53(.70) 1.52 (.57) 1.38 (.57) 1.38 (.58) 1.251.301.351.401.451.501.551.60 Up tp 25 Lbs. (n = 45) 26 to 50 Lbs. (n = 47) 51 to 75 Lbs. (n = 31) 101 to 150 Lbs. (n = 19) 76 to 100 Lbs. (n = 33) More Than 150 Lbs. (n = 56) Injury Severity Mean (Standard Deviation) Figure 468. Comparison of injury severity mean by agent of weighted item related injuries. Date of Injury Year of Occurrence of Injury Information regarding the year in which the injury occurred was provided for 46,012 worker injuries. Injury frequency by the year of th e injury is shown in Ta ble 447. Over 18% of the injuries (n = 8,499) were reported to have occurred during the year 2001. Over 15% of the injuries occurred in 2002 (n = 7,961) and 2000 (n = 7,223). Over 13% of the injuries occurred in 2003 (n = 6,159), and nearly 12% of the injuries occurred in 2004 (n = 5,501). Slightly less than

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184 10% of the injuries occurred in 2005 (n = 4,532), and 1999 was associated with slightly over 8% of the injuries (n = 3,802). Almost 5% of th e injuries were recorded for 1998 (n = 1,255), 1997 (n = 576), and 1996 (n = 282). For 2006, data were available only for the month of January. These accounted for less than one % of all the injuries (n = 222). Table 447. Year of injury. Year of injury Number of injuries % Cumulative % 2001 8,49918.47%18.47% 2002 7,96117.30%35.77% 2000 7,22315.70% 51.47% 2003 6,15913.39%64.86% 2004 5,50111.96% 76.81% 2005 4,5329.85%86.66% 1999 3,8028.26% 94.92% 1998 1,2552.73%97.65% 1997 5761.25%98.90% 1996 2820.61%99.52% *2006 2220.48%100.00% Total 46,012100.00% For January only. A comparison of the injury severity mean s was conducted for the reported years of injuries. The results of the Levene test of homogeneity of injury severity score variances for the years of the injury did not allow for the assumption of equal variances, L (10, 45,323) = 95.90, p < .001. Subsequently, the Welch robust test of eq uality of injury severity means was conducted to detect possible differences of inju ry severity means, significant at p 0.05, by year of occurrence. The results of this test did show th at any year had a significantly different injury severity mean than one of th e other years, F (10, 3,298.66) = 30.56, p < .001. This was confirmed by the results of the Tukeys b range test (see Figure 469). The results of the Tukeys b range test are displayed in Figure 470. It shows that the injury severity means associated with injuri es sustained during 2001 ( = 1.38) and 2002 ( = 1.38) had significantly greater injury severity means, at p 0.05, than injury severity means for

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185 the years of 2004 ( = 1.29), 2005 ( = 1.24), and 2006 ( = 1.15). Injury severity means for the years of 1996 ( = 1.35), 1997 ( = 1.35), 2003 ( = 1.34) and 2000 ( = 1.33) were significantly greater, at p 0.05, than the injury severity means associated with the years of 2005 and 2006. The years of 1998 ( = 1.32), 1999 ( = 1.30), 2004, and 2005each had a significantly greater injury severity mean than that for 2006. 1.38 (0.65) 1.38 (0.64) 1.35 (0.60) 1.35 (0.61) 1.34 (0.61) 1.33 (0.61) 1.32 (0.53) 1.30 (0.53) 1.29 (0.55) 1.24 (0.50) 1.15 (0.46) 0.000.200.400.600.801.001.201.401.60 2006 (n = 191) 2005 (n = 4434) 2004 (n = 5417) 1999 (n = 3758) 1998 (n = 1235) 2000 (n = 7163) 2003 (n = 6069) 1997 (n = 573) 1996 (n = 280) 2002 (n = 7794) 2001 (n = 8420) Injury Severity Mean (Standard Deviation) Figure 469. Comparison of injury severity means by year of occurrence. Between the years of 2001 and 2006 there appeared to be a downward trend in the severity of injuries. The results of a Kendalls tau test for correlation between injury severity and the year of the injury of 2001 through 2005 indicat ed a slight, though significant, at p 0.01, correlation of -0.04. 1.38 (0.65) 1.38 (0.64) 1.35 (0.60) 1.35 (0.61) 1.34 (0.61) 1.33 (0.61) 1.32 (0.53) 1.30 (0.53) 1.29 (0.55) 1.24 (0.50) 1.15 (0.46) 0.000.200.400.600.801.001.201.401.60 2006 (n = 191) 2005 (n = 4434) 2004 (n = 5417) 1999 (n = 3758) 1998 (n = 1235) 2000 (n = 7163) 2003 (n = 6069) 1997 (n = 573) 1996 (n = 280) 2002 (n = 7794) 2001 (n = 8420) Injury Severity Mean (Standard Deviation) Figure 470. Differences of injury seve rity means between years of occurrence.

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186 Month of Occurrence of Injury The month the injured occurred on was made available for 46,056 workers. Table 448 displays the distribution of the injuries by mont h of the year in which the injury occurred. Information regarding the month of the injury was provided for 46,056 worker injuries. Between eight and 10 % of the injuries occurred in each of the months of August (n = 4,473), October (n = 4,421), July (n = 4,330), September (n = 4,080), June (n = 3,983), May (n = 3,824), March (n = 3,778), and April (n = 3,701). Less than eight % of the injuries were represented within the coldest months of November (n = 3,577), January (n = 3,516), December (n = 3,208), and February (n = 3,165). Table 448. Month of injury. Month of injury Number of injuries % Cumulative % August 4,4739.71% 9.71% October 4,4219.60% 19.31% July 4,3309.40% 28.71% September 4,0808.86% 37.57% June 3,9838.65% 46.22% May 3,8248.30% 54.52% March 3,7788.20% 62.72% April 3,7018.04% 70.76% November 3,5777.77% 78.53% January 3,5167.63% 86.16% December 3,2086.97% 93.13% February 3,1656.87% 100.00% Total 46,056100.00% A comparison of the injury severity means was conducted for the months of injury occurrence. The results of the Levene test of hom ogeneity of injury severity score variances for the years of injury did not allow for the assumption of equal variances, L (10, 45,364) = 3.43, p < .001. Subsequently, the Welch robust test of equali ty of injury severity means was conducted to detect possible differences of inju ry severity means, significant at p 0.05, for the months of

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187 injury occurrence. The results of this test di d not show any significant difference of injury severity means between the months, F (11, 17,594.90) = 1.41, p > 0.10. This was confirmed by the results of the Tukeys b range test (see Figure 471). 1.32 (.60) 1.32 (.59) 1.32 (.60) 1.32 (.60) 1.32 (.59) 1.33 (.60) 1.33 (.58) 1.33 (.59) 1.34 (.59) 1.34 (.61) 1.35 (.61) 1.35 (.61) 1.281.301.321.341.36 July (n = 4270) September (n = 4024) December (n = 3137) August (n = 4419) November (n = 3535) June (n = 3935) May (n = 3792) March (n = 3701) October (n = 4377) April (n = 3634) February (n = 3106) January (n = 3446) Injury Severity Mean (Standard Deviation) Figure 471. Comparison of injury severi ty means by month of injury occurrence. Day of the Week of Occurrence of Injury The day of the week on which the injury was recorded to have occurred was provided for 46,056 workers. Table 449 displays the distributi on of injuries for the days of the week in which the injury occurred. Information regarding th e day of the week of injury occurrence was provided for 46,056 worker injuries. Almost 19% of the injuries occurred on Tuesdays (n = 8,885), Wednesdays (n = 8,745), Mondays (n = 8,693), and Thursdays (n = 8,678). Less than 17% of the injuries occurred on Fridays (n = 7,7 40). Just over 5% of the injuries occurred on Saturdays (n = 2,440) while Sundays (n = 875) were a ssociated with less than 2% of the injuries. A comparison of the injury severity means was conducted for the reported days of the week on which the injuries occurred. The results of the Levene test of homogeneity of injury score variances between the years of the inju ry did not allow for the assumption of equal variances, L (6, 45,369) = 12.33, p < .001. Subsequently, the Welch robust test of equality of injury severity means was conducted to detect pos sible differences of injury severity means,

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188 significant at p 0.05, between the days of the week. The resu lts of this test showed that at least one of the days of the week had a significantly diffe rent injury severity mean than one or more of the other days, F (6, 8,474.06) = 4.013, p .001. This was confirmed by the results of the Tukeys b range test (see Figure 472). Table 449. Day of the week of injury. Day of the week of injury Numb er of injuries % Cumulative % Tuesday 8,88519.29% 19.29% Wednesday 8,74518.99% 38.28% Monday 8,69318.87% 57.15% Thursday 8,67818.84% 75.99% Friday 7,74016.81% 92.80% Saturday 2,4405.30% 98.10% Sunday 8751.90% 100.00% Total 46,056100.00% Injuries occurring on Saturdays ( = 1.37) or Sundays ( = 1.37) ha d the highest injury severity mean ( = 1.37). These were followed by injuries on Fridays or Mondays ( = 1.34). Injuries occurring on Tuesdays, Thursdays and Wednesdays had the lowest injury severity means, = 1.32). 1.37 (.63) 1.37 (.65) 1.34 (.60) 1.34 (.60) 1.32 (.59) 1.32 (.59) 1.32 (.59) 1.261.281.301.321.341.361.381.40 Wednesday (n = 8613) Thursday (n = 8544) Tuesday (n = 8754) Monday (n = 8552) Friday (n = 7623) Saturday (n = 2425) Sunday (n = 865) Injury Severity Mean (Standard Deviation) Figure 472. Comparison of injury severity m eans by day of the week of injury occurrence. Results for significant injury se verity mean differences, at p 0.05, by Day of the week of occurrence the results were discerned and are dislpayed in Figure 473. The injury severity means associated with injuries occurring on Sundays ( = 1.37) or Saturdays ( = 1.37) had

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189 significantly greater injury severity means, at p 0.05, than injury severity means for injuries occurring on Tuesdays ( = 1.32), Thursd ays ( = 1.32), or Wednesdays ( = 1.32). 1.37 (.63) 1.37 (.65) 1.34 (.60) 1.34 (.60) 1.32 (.59) 1.32 (.59) 1.32 (.59) 1.261.281.301.321.341.361.381.40 Wednesday (n = 8613) Thursday (n = 8544) Tuesday (n = 8754) Monday (n = 8552) Friday (n = 7623) Saturday (n = 2425) Sunday (n = 865) Injury Severity Mean (Standard Deviation) Figure 473. Differences of injury severity means between days of the week of injury occurrence. Injury Profiles by Body Region Body Region Information regarding the Body region directly impacted by the loss event was provided for 45,966 worker injuries. Table 450 shows the di stribution of injuries for the six body regions directly impacted by injuries. Upper extremity injuries (n = 13,152, 28.61%), injuries to the trunk (n = 11,646, 25.34%) and injuries to the lower extremities (n = 9,196, = 20.01%) accounted for over 70% of the total number of injuries. As an a ggregate, injuries to the head (n = 7,539), neck (n = 985), and to multiple body parts or body systems (n = 3,448) were just over 25% of the injuries. Table 450. Body region injured. Body region Number of injuries % Cumulative % Upper extremities 13,15228.61% 28.61% Trunk 11,64625.34% 53.95% Lower extremities 9,19620.01% 73.95% Head 7,53916.40% 90.35% MBRBS* 3,4487.50% 97.85% Neck 9852.14%100.00% Total 45,966100.00% *Multiple body regions or body systems

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190 The severity of injuries associated wi th each of the body regions was examined by comparing injury severity means between the six categories. The results of the Levene test for homogeneity of variances did not allow for the a ssumption of equal variances of injury severity scores for the six body regions, L (5, 45,285) = 1257.86, p < 0.001. The results of the subsequent Welch test showed that at least one of the body regions had a significantly different injury severity mean than one or more of the other five regions, F (5, 7,664.22) = 531.46, p < 0.001. This was confirmed by the results of Tuke ys b range test (s ee Figure 474). Neck injuries had the highest injury severity mean ( = 1.48). Multiple body part injuries or injuries to body systems ranked second ( = 1.47). This was followed by trunk injuries ( = 1.44), injuries to the lower extremities ( = 1.40) and upper extremities ( = 1.26). Head injuries reflected the lowest injury severity mean, = 1.11. Specific significantly diffe rent injury severity means, at p 0.05, were discerned from Figure 4and displayed in Figure 475. 1.48 (.70) 1.47 (.75) 1.44 (.64) 1.40 (.62) 1.26 (.54) 1.11 (41) 0.000.200.400.600.801.001.201.401.60 Head (n = 7427) Upper Extremities (n = 12939) Lower Extremities (n = 9083) Trunk (n = 11490) Multiple Body Parts or Body Systems (n = 3388) Neck (n = 964) Injury Severity Means (Standard Deviation) Figure 474. Comparison of injury severity means by body region.. At the significance level of p 0.05, injuries to the neck, multiple body parts or body systems, and to the trunk had signifi cantly higher injury severity means than injuries to the lower and upper extremities and injuries to the head (see Figure 475). Injuries to the lower extremities had a significantly greater injury severity mean, at p 0.05, than injuries to the upper extremities

PAGE 191

191 and head injuries. Injuries to the lower ex tremities were significantly more severe, at p 0.05, than head injuries. 1.48 (.70) 1.47 (.75) 1.44 (.64) 1.40 (.62) 1.26 (.54) 1.11 (41) 0.000.200.400.600.801.001.201.401.60 Head (n = 7427) Upper Extremities (n = 12939) Lower Extremities (n = 9083) Trunk (n = 11490) Multiple Body Parts or Body Systems (n = 3388) Neck (n = 964) Injury Severity Means (Standard Deviation) Figure 475. Differences of injury severity means between body regions. Body Region and Age Even though age is not a cause of injury, it can be used as an approximate measure of human limitations and behaviors, in cluding exposure to more or less risky activities that result in conditions that affect vulnerability of various body regions and body parts. Age often indicates differential risk that can be used to target injury control efforts. Possible associations of age with the body regions that were injured were exam ined. Information regarding age and the body region affected by the injury was provided for 14,909 worker injuries. Since equal variances of injury severity scores could not be assumed, L (5, 14,903) = 2.55, p < 0.03, a Welch robust test of the equality was conducted of mean age for th e six body region groups. The results of this test showed that at least one of the body regions disp layed a mean age that was significantly different from one or more of the other groups, F (5, 2,576.46) = 10.97, p < 0.001.This was confirmed by the results of the Tukeys range test which were significant at p 0.05 (see Figure 476). Neck injuries reflected the highest mean ag e ( = 38.56), followed by injuries to the trunk ( = 38.30), multiple body part or body system in juries ( = 38.22), injuries to the lower

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192 extremities ( = 38.04), and upper extremities ( = 37.00). Head injuries were associated with the lowest mea age, = 36.67). From the Tukeys b test it was determined that, as a group, individuals who experienced either neck injuries and injuries to the trunk had signifi cantly greater, at p 0.05, mean ages than did workers who had injuries to either the upper extremities and to the head. Injuries to the lower extremities had a significantly lower, at p 0.05, mean age than those with head injuries (see Figure 4 77). 38.56 (9.97) 38.30 (11.13) 38.22 (11.30) 38.04 (11.24) 37.00 (11.20) 36.68 (10.91) 35.5036.0036.5037.0037.5038.0038.5039.00 Head (n = 2376) Upper Extremities (n = 4335) Lower Extremities (n = 2949) Multiple Body Parts or Body Systems (n = 1143) Trunk (n = 3789) Neck (n = 317) Injury Severity Mean (Standard Deviation) Figure 476. Mean age by injured body region. 38.56 (9.97) 38.30 (11.13) 38.22 (11.30) 38.04 (11.24) 37.00 (11.20) 36.68 (10.91) 35.5036.0036.5037.0037.5038.0038.5039.00 Head (n = 2376) Upper Extremities (n = 4335) Lower Extremities (n = 2949) Multiple Body Parts or Body Systems (n = 1143) Trunk (n = 3789) Neck (n = 317) Injury Severity Mean (Standard Deviation) Figure 477. Difference of mean ages between injured body regions.

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193 Experience Level Information pertaining to the occupational e xperience level of the injured worker by body region was made available for 14,374 injuries. Table 451 and Table 452 display the ranking of the body regions, according to relative freque ncy within their General Occupational Experience groups, for both field based pers onnel and administrative based personnel, respectively. Laborers, apprentices, journeym en, and foremen have similar ranking profiles among the field based personnel. Each show injuries to the upper extremities as the most frequent within their respective occupational level, followed by injuries to the trunk, lower extremities, head injuries, injuries to multiple body parts or body systems, and finally, neck injuries (see Table 451). Among helper or assistant level worker s, head injuries ranked third, followed by injuries to the lower extremities a nd neck injuries. Field supervisory personnel showed injuries to the lower extremities as ranking second, behind upper extremities, in frequency of injury and trunk injuries ranked third Table 452 shows that among administrative workers, in juries to the trunk, upper extremities, and lower extremities ranked clos ely in first, second, and third positions. Professional level workers, such as professional engineers and project managers, showed injuries to lower extremities, trunk, and upper extremities as ranking first, second, and third, respectively. For both administrative based personnel groups, head injuries, injuries to multiple body parts or body systems, and neck injuries, ranked fourth, fifth, and sixth, respectively. Laborers Information regarding the injury distribution by body region was provided for 7,913 in injured laborers (see Table 453). Among laborer s, injuries to the upper extremities (n = 2,240, 28.31%), trunk (n = 2,147, 27.13%), and lower ex tremities (n = 1,784, 22.55%) clearly exceeded

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194 Table 451. Ranking of injured body regions by injury distributi on for occupational experience level among field based personnel. Field Personnel Laborers Helpers/ assistants Apprentices Journeymen Foremen Field Supervisors Overall Rank N = 7913 N = 752 N = 1,576 N = 1,538 N = 1,449 N = 612 UE* UE UE UE UE UE UE n = 4,182 n = 2,246 n = 216 n = 560 n = 426 n = 416 n = 166 29.09% 1 28.31% 28.72% 35.53% 31.37% 28.71% 27.12% T T T T T T LE n = 3,823 n = 2,147 n = 194 n = 365 n = 377 n = 407 n = 163 26.60% 2 27.13% 25.80% 23.16% 27.76% 28.09% 26.63% LE LE H LE LE LE T n = 3,169 n = 1784 n = 142 n = 299 n = 272 n = 337 n = 149 22.05% 3 22.55% 18.88% 18.97% 20.03% 23.26% 24.35% H H LE H H H H n = 1,996 n = 1,044 n = 138 n = 259 n = 187 n = 181 n = 78 13.89% 4 13.19% 18.35% 16.43% 13.77% 12.49% 12.75% MBP/BS MBP/BS MBP/BS MBP/BS MBP/BS MBP/BS MBP/BS n = 897 n = 541 n = 48 n = 57 n = 59 n = 79 n = 39 6.24% 5 6.84% 6.38% 3.62% 4.34% 5.45% 6.37% NK NK NK NK NK NK NK n = 307 n = 157 n = 14 n = 365 n = 37 n = 29 n = 17 2.14% 6 1.98% 1.86% 2.28% 2.72% 2.00% 2.78% *NK = Neck, UE = Upper Extremities, T = Trunk, LE = Lower Extremities, H = Head, MBPS/BS = Multiple Body Systems, Parts/Body Table 452. Ranking of injured body regions by injury distributi on for occupational experience level among administrative based personnel. Administrative & Professional Personnel Administrative Professional Overall Rank N = 448 N = 752 UE* T LE n = 4,182 n = 114 n = 71 29.09% 1 25.45% 26.69% T UE T n = 3,823 n = 108 n = 70 26.60% 2 24.11% 26.32% LE LE UE n = 3,169 n = 105 n = 50 22.05% 3 23.44% 18.80% H H H n = 1,996 n = 69 n = 36 13.89% 4 15.40% 13.53% MBP/BS MBP/BS MBP/BS n = 897 n = 44 n = 30 6.24% 5 9.82% 11.28% NK NK NK n = 307 n = 8 n = 9 2.14% 6 1.79% 3.38% *NK = Neck, UE = Upper Extremities, T = Trunk, LE = Lower Extremities, H = Head, MBPS/BS = Multiple Body Systems, Parts/Body

PAGE 195

195 injuries to the head (n = 1,044, 1,044, 13.19%), multiple body parts or body systems (n = 541, 6.84%), and neck (n = 157, 1.98%). The injury severity was examined for the six body regions for laborers. The results of the Levene test for homogeneity of variances of th e injury severity scores did not allow for the assumption of equal injury severity score vari ances for the six body regions for laborers, L (5, 7,829) = 188.07, p < 0.001. The Welch test statistic subse quently showed that, among laborers, at least one of the body regions had a significantly different injury severity mean of one or more of the other body regions, F (5, 1,237.04) = 63.93, p < 0.001. This was confirmed by the Tukeys b range test which compared individual injury severity means, for each of the body regions. The results of the Tukeys b range test ar e reflected in Figure 478 and Figure 479. Figure 478 shows the homogeneous groupings of injury severity means for the six body regions. Among laborers, injuries to the neck ha d the highest injury severity mean ( = 1.57), followed by multiple body parts or body systems injuries ( = 1.57), injuries to the trunk region ( = 1.50), lower extremities ( = 1.45), and upper extremities ( = 1.27). Head injuries among laborers showed the lowest inju ry severity mean ( = 1.13). Table 453. Injuries to laborers by body region. Body region Number of injuries % Cumulative % Upper extremities 2,24028.31% 28.31% Trunk 2,14727.13% 55.44% Lower extremities 1,78422.55% 77.99% Head 1,04413.19% 91.18% MBRBS* 5416.84% 98.02% Neck 1571.98% 100.00% Total 7,913100.00% MBRBS = Multiple body regions or body systems. Figure 479 shows the means that are significantly different, at p 0.05, of each other. Among laborers, injuries to the neck had a significantly higher, at p 0.05, injury severity mean ( =

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196 1.57) than all of the other body regions, except that of multiple body injuries ( = 1.50). Multiple body part injuries showed a significantly greater injury severity mean, at p 0.05, than 1.57 (.75) 1.13 (.40) 1.27 (.54) 1.38 (.60) 1.45 (.63) 1.50 (.70) 0.000.200.400.600.801.001.201.401.601.80 Head (n = 1030) Upper Extremities (n = 2216) Lower Extremities (n = 1769) Trunk (n = 2131) Multiple Body Parts or Body Systems (n = 532) Neck (n = 157) Laborers: Injury Severity Means (Standard Deviation) Figure 478. Comparison of injury severity means by body region for laborers. injuries to lower extremities ( = 1.38), upper ex tremities ( = 1.27) and head injuries ( = 1.13). Injuries to the trunk ( = 1.45) and lower extrem ities each had a significantly greater injury severity mean, at p 0.05, than injuries to the upper extremitie s, and head injuries. Injuries to the upper extremities of laborers had a signifi cantly greater injury severity mean, p 0.05, than head injuries among laborers. 1.57 (.75) 1.13 (.40) 1.27 (.54) 1.38 (.60) 1.45 (.63) 1.50 (.70) 0.000.200.400.600.801.001.201.401.601.80 Head (n = 1030) Upper Extremities (n = 2216) Lower Extremities (n = 1769) Trunk (n = 2131) Multiple Body Parts or Body Systems (n = 532) Neck (n = 157) Laborers: Injury Severity Means (Standard Deviation) Figure 479. Differences of mean ag es between body regions for laborers. Helpers/Assistants Information regarding the body region affected by the injury was provided for 752 workers identified at the helper or a ssistant Experience Level. As sh own in Table 454, helpers and

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197 assistants had a similar to injury profile to that of laborers. Among helpers and assistants, injuries to the upper extremities (n = 215, 28.72%) and tr unk (n = 194, 25.80%) comprised over 50% of the total number of injuries experienced by he lpers or assistants. However, head injuries comprised a greater proportion of the injuries to helpers or assistants than to laborers. Head injuries (n = 142, 18.88%) and injuries to lowe r extremities (n = 138, 18.35%), ranked a virtual tie for the third most injured body region experi enced by helpers or assistants. Injuries to multiple body or body systems accounted for 6.38% (n = 48) of the injuries recorded for workers at the helper or assistant experience level. N eck injuries accounted for less 2% (n = 14) of injuries to helpers or assistants. Table 454. Injuries to helper s and assistants by body region. Body region Number of injuries % Cumulative % Upper extremities 21628.72% 28.72% Trunk 19425.80% 54.52% Head 14218.88% 73.40% Lower extremities 13818.35% 91.75% MBRBS* 486.38% 98.13% Neck 141.86% 100.00% Total 752100.00% MBRBS = Multiple body regions or body systems. The injury severity was examined for the six body regions among injuries to helper/assistants. The results of the Levene test for homogeneity of variances of the injury severity scores did not allow for the assu mption of equal variances, L (5, 732) = 24.40, p < 0.001. Subsequently, the results of a Welch test of the equality of the injury severity means for the body regions for helpers or assistants showed that at least one of the body region categories had a significantly different injury severity mean than one or more of the other body regions, F (5, 100.31) = 11.33, p < .001. Figure 4 80 shows the results of the Tukeys b range test and confirms the results of the We lch test. The two homogeneous groupings of injury severity means

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198 for body regions suggests that for helpers or assist ants a statistically significant difference, at p 0.05, of injury severity means exists between these groups. The results of the Tukeys b range test (see Figure 480) shows that the most severe injuries among helpers or assistants were inju ries sustained by multiple body parts or upon body systems ( = 1.50). This was followed by, as a homogeneous subset in descending order of severity, injuries to the trunk ( = 1.41), lo wer extremities ( = 1.39), neck ( = 1.31), upper extremities ( = 1.22), and head ( = 1.10). 1.10 (.30) 1.22 (.53) 1.31 (.48) 1.39 (.60) 1.41 (.61) 1.50 (.78) 0.000.200.400.600.801.001.201.401.60 Head (n = 140) Upper Extremities (n = 213) Neck (n = 13) Lower Extremities (n = 133) Trunk (n = 193) Multiple Body Parts or Body Systems (n = 46) Injury Severity Mean (Standard Deviation) Figure 480. Comparison of injury severity means by body region injuries to helpers and assistants. Figure 481 shows that, among helpers or assi stants, injuries to multiple body parts or body regions had a significantly greater, at p 0.05, injury severity m ean than head injuries. 1.10 (.30) 1.22 (.53) 1.31 (.48) 1.39 (.60) 1.41 (.61) 1.50 (.78) 0.000.200.400.600.801.001.201.401.60 Head (n = 140) Upper Extremities (n = 213) Neck (n = 13) Lower Extremities (n = 133) Trunk (n = 193) Multiple Body Parts or Body Systems (n = 46) Injury Severity Mean (Standard Deviation) Figure 481. Differences of injury severity means between body regions injured among helpers and assistants.

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199 Apprentice Among apprentice level workers, information regarding injuries to the six body regions was provided for 1,576 worker injuries. As a group, apprentices experienced a higher proportion of injuries to the upper extremities (n = 560, 35.53 %) than any of the other general occupational experience groups. Injuries to the upper extrem ities comprised over 35% of the injuries to apprentices (see Table 455). In descending percentages, over 58% of the inju ries to apprentices were comprised of injuries to the trunk (n = 365, 23.16%), lower extremities (n = 299, 18.97%) and to the head (n = 259, 16.43%). Less than 4% of the injuries to apprentice level workers were injuries to multiple body parts or body systems (n = 57, 3.62%), while just over 2% of the injuries were to the neck (n = 36, 2.28%). Table 455. Injuries to b ody regions among apprentices. Body region Number of injuries % Cumulative % Upper extremities 56035.53% 35.53% Trunk 36523.16% 58.69% Lower extremities 29918.97% 77.66% Head 25916.43% 94.10% MBRBS 573.62% 97.71% Neck 362.28% 100.00% Total 1,576100.00% MBRBS = Multiple body regions or body systems. The injury severity was examined for the six body regions among apprentices. The results of the Levene test for homogeneity of variances of the injury severity scores did not allow for the assumption of equal variances, L (5, 1,559) = 43.85, p < 0.001. The results of the subsequent Welch test for the equality of injury severi ty means showed a greater between body region difference than within body region diffe rence for apprentices, F (5, 220.07) = 16.24, p < 0.001. This was confirmed by the results of the Tukeys b range test (see Figure 482). The Tukeys b range test was conducted to ex amine the specific distribution of injury severity means for the six body region groups for apprentice level workers. Figure 482

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200 identifies homogeneous groups, whose injury severi ty means are not different at a statistically significant level of p 0.05. Three discreet homogeneous gro ups suggest that several of the body regions among apprentice level workers have significantly different injury severity means, at p 0.05, than one of the other body regions. Among a pprentices injuries to multiple body parts or body systems had the highest injury severity mean ( = 1.64). This was followed by trunk injuries ( = 1.43), neck injuries ( = 1.37), in juries to the lower extremities ( = 1.37), and injuries to the upper extremities ( = 1.25). Head injuries among apprentices had the lowest injury severity mean ( = 1.11). 1.64 (.88) 1.43 (.61) 1.37 (.55) 1.37 (.58) 1.25 (.52) 1.11 (.39) 0.000.200.400.600.801.001.201.401.601.80 Head (n = 258) Upper Extremities (n = 555) Lower Extremities (n = 297) Neck (n = 35) Trunk (n = 364) Multiple Body Parts or Body Systems (n = 56) Injury Severity Mean (Standard Deviation) Figure 482. Comparison of injury severity means by body regions injured among apprentices. Among apprentice level workers, injuries to multiple body parts or body systems had a significantly greater inju ry severity mean, at p 0.05, than injuries to all the remaining body regions (see Figure 483). Injuries to the trunk, neck, and the lower extremities, showed a significantly greater inju ry severity mean, at p 0.05, than that for injuries to the head. 1.64 (.88) 1.43 (.61) 1.37 (.55) 1.37 (.58) 1.25 (.52) 1.11 (.39) 0.000.200.400.600.801.001.201.401.601.80 Head (n = 258) Upper Extremities (n = 555) Lower Extremities (n = 297) Neck (n = 35) Trunk (n = 364) Multiple Body Parts or Body Systems (n = 56) Injury Severity Mean (Standard Deviation) Figure 483. Differences of injury severity means between body regions among apprentices.

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201 Journeymen Information for journeyman level workers regarding injuries for the six body regions was provided for 1,358 workers (see Table 456). Over 30% of the injuries to journeymen were injuries to the upper extremities (n = 426, 31.37 %). Injuries to the trunk (n = 377, 27.76%) and lower extremities (n = 272, 20.03%) combined to account for over 47% of the total number of injuries to journeymen. Injuries to neck co mprised the lowest percentage (n = 37, 2.72%) of injuries to journeymen. Head in juries accounted for just over 13% (n = 187) of the injuries to journeymen. Slightly more than four % of the in juries to journeymen were multiple body part or body systems injuries (n = 59). Table 456. Injuries to journeymen by body region. Body region Number of injuries % Cumulative % Upper extremities 42631.37% 31.37% Trunk 37727.76% 59.13% Lower extremities 27220.03% 79.16% Head 18713.77% 92.93%MBRBS* 594.34% 97.28% Neck 372.72% 100.00% Total 1,358100.00% MBRBS = Multiple body regions or body systems. Injury severity was examined for the six body regions among journeymen. The results of the Levene test for homogeneity of variances of the injury severity scor es would not allow for the assumption of equal variances, L (5, 1,344) = 54.61, p 0.001. The results of the Welch robust test of equality of injury severity means for the six regions showed a greater between body region difference than within body region difference in injury severity means for journeymen, F (5, 226.63) = 21.09, p 0.001. This was confirmed by the results of the Tukeys b range test. The Tukeys b range test was conducted to ex amine the specific distribution of injury severity means for the six body region groups fo r journeymen. Figure 484 identifies the Tukeys b homogeneous subsets, in which injury severity means ar e not significantly different at

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202 p .0.05. Figure 4 84 shows the groupings which show ed significantly different injury severity means, at p 0.05. Among journeymen, injuries to multip le body parts had the highest injury severity mean ( = 1.79). Trunk inju ries constituted the second highe st injury severity mean ( = 1.50), followed by injuries to the lower extrem ities ( = 1.49), neck ( = 1.38), and upper extremities ( = 1.30). Head injuries had the lowe st injury severity mean among journeymen, = 1.09). Among journeymen, injuries to multiple body parts or body systems had a significantly greater, at p 0.05, injury severity mean, than injuri es to the trunk, lower extremities, neck, upper extremities, and head injuries (see Figure 485). Injuries to the trunk, lower extremities, neck, and upper extremities showed significantly greater injury severity means, at p 0.05, than head injuries among journeymen 1.09 (.30) 1.30 (.56) 1.38 (.55) 1.49 (.64) 1.50 (.63) 1.79 (.97) 0.000.200.400.600.801.001.201.401.601.802.00 Head (n = 185) Upper Extremities (n = 426) Neck (n = 37) Lower Extremities (n = 271) Trunk (n = 373) Multiple Body Parts or Body Systems (n = 58) Injury Severity Mean (Standard Deviation) Figure 484. Comparison of injury severi ty means by body region among journeymen.). 1.09 (.30) 1.30 (.56) 1.38 (.55) 1.49 (.64) 1.50 (.63) 1.79 (.97) 0.000.200.400.600.801.001.201.401.601.802.00 Head (n = 185) Upper Extremities (n = 426) Neck (n = 37) Lower Extremities (n = 271) Trunk (n = 373) Multiple Body Parts or Body Systems (n = 58) Injury Severity Mean (Standard Deviation) Figure 485. Differences of injury severi ty means between body regions among journeymen.

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203 Foreman Information pertaining to injuries associated with the body regions a ffected by the injury was provided for 1,449 foreman level workers (see Table 457). Among foremen, injuries to the upper extremities (n = 416) and to the trunk (n = 407) accounted for over 28% of the injuries, each. Injuries to the lower extrem ities accounted for just over 23% (n = 337) of the injuries to foremen. Slightly over 12% of the injuries to foremen were head injuries. Injuries to multiple body parts or body systems (n = 79) and neck injuries (n = 29) combined to account for slightly less than eight % of the injuries to foremen. Table 457. Injuries to foremen by body region. Body region Number of injuries % Cumulative % Upper extremities 41628.71% 28.71% Trunk 40728.09% 56.80% Lower extremities 33723.26% 80.06% Head 18112.49% 92.55%MBRBS* 795.45% 98.00% Neck 292.00% 100.00% Total 1,449100.00% MBRBS = Multiple body regions or body systems. Injury severity relative to the six body regions was examined by using statistics which compared injury severity mean s for the body regions among foremen. The results of the Levene test of homogeneity of variances of injury seve rity scores for the six body regions did not allow for an assumption of equal variances, L (5, 1,428) = 32.76, p < 0.001. The results of the subsequent Welch test of equality of injury severity means indicated that, among foremen, at least one of the body regions had a significantly diffe rent injury severity mean than one of the other regions, F (5, 211.14) = 13.69, p < 0.001. This was confirmed by the results of the Tukeys b range test (see Figure 486 and Figure 487). The results of the Tukeys b range test are shown in Figure 486. Two homogeneous subsets of injury severity m eans were identified. Among foremen, injuries to lower extremities

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204 had the highest injury severity mean ( = 1.48) followed by inju ries to the neck ( = 1.45), multiple body parts or body systems injuries ( = 1.43), injuries to the trunk ( = 1.41), and upper extremities ( = 1.26). Head injuries showed the lowest injury severity mean ( = 1.12) among foremen 1.48 (.68) 1.45 (.63) 1.43 (.82) 1.41 (.60) 1.26 (.55) 1.12 (.45) 0.000.200.400.600.801.001.201.401.60 Head (n = 178) Upper Extremities (412) Trunk (n = 405) Multiple Body Parts or Body Systems (n = 76) Neck (n = 29) Lower Extremities (n = 334) Injury Severity Mean (Standard Deviation) Figure 486. Comparison of injury se verity means by body region among foremen. From the arrangement of the homogeneous subs ets in Figure 486, it was discerned that, among foremen, injuries to the lower extremitie s, neck, multiple body parts or body regions, and trunk each had a significantly great er injury severity mean, at p 0.05, than that of head injuries (see Figure 487). 1.48 (.68) 1.45 (.63) 1.43 (.82) 1.41 (.60) 1.26 (.55) 1.12 (.45) 0.000.200.400.600.801.001.201.401.60 Head (n = 178) Upper Extremities (412) Trunk (n = 405) Multiple Body Parts or Body Systems (n = 76) Neck (n = 29) Lower Extremities (n = 334) Injury Severity Mean (Standard Deviation) Figure 487. Differences of injury severity means between body region injuries to foremen.

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205 Field Supervision Field supervision level workers were thos e who were not specifically identified as foremen, but could be identified as acting in a supervisory capacity on the jobsite. This group included superintendents, assistan t superintendents, project manage rs, and field engineers. Table 458 shows that injuries to the upper extremities (n = 166), lo wer extremities (n = 163), and trunk (n = 149) each accounted for around 25% of the injuries to field supervisors. Head injuries (n = 78) occurred to almost 13% of field supervis ors, neck injuries (n = 17), and injuries to multiple body parts or body systems combined for less than ten % of the injuries. Table 458. Injuries to fi eld supervisors by body region. Body region Number of injuries % Cumulative % Upper extremities 16627.12%27.12% Lower extremities 16326.63%53.75% Trunk 14924.35% 78.10% Head 7812.75% 90.85%MBRBS* 396.37%97.22% Neck 172.78% 100.00% Total 612100.00% MBRBS = Multiple body regions or body systems. Injury severity was examined for the six body regions for field supervisory level workers. The results of the Levene test for homogeneity of variances of the injury severity scores did not allow for the assumption of equal variances, L (5, 595) = 5.30, p < 0.001. The results of the Welch test of equality of injury severity means for the body regions showed that at least one of the body regions had a significantly different injury severity mean than one or more of the other body regions among field supervisors, F (5, 110.25) = 2.50, p <.04. This result was not confirmed by the Tukeys range test, significant at p 0.05. The homogeneous subsets generated by the Tukeys b range test are displayed in Figure 488. The results showed that none of the body regions had a significantly different injury severity mean, at p 0.05, than any of the other body regions. For field supervisors, injuries to multiple

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206 body parts showed the highest inju ry severity mean ( = 1.49), followed by injuries to lower extremities ( = 1.36), head injuries ( = 1.32), injuries to the trunk ( = 1.30), and upper extremities injuries ( = 1.20, a nd neck injuries ( = 1.19). 1.19 (.40) 1.20 (.47) 1.30 (.53) 1.32 (.90) 1.36 (.62) 1.49 (.60) 0.000.200.400.600.801.001.201.401.60 Neck (n = 16) Upper Extremities (n = 163) Trunk (n = 148) Head (n = 76) Lower Extremities (n = 159) Multiple Body Parts or Body Systems (n = 39) Injury Severity Mean (Standard Deviation) Figure 488. Comparison of injury severity means by body region among field supervisors. Professional Professional level workers include d professional engineers (n = 121) and inspectors (n = 144). Among 266 injured professional level workers, inju ries to the lower extremities and to the trunk, each accounted for over 26% of the injuries to professional level workers (see Table 4-59). Upper extremities injuries accounted for over 18% of the injuries, and injuries to head comprised over 13% of the injuries to profe ssional level workers. Over 11% of the injuries to professionals were to multiple body parts or body systems, with less than 4% being neck injuries. Table 459. Injuries to professionals by body region. Body region Number of injuries % Cumulative % Lower extremities 7126.69% 26.69% Trunk 7026.32% 53.01% Upper extremities 5018.80% 71.80% Head 3613.53% 85.34%MBRBS* 3011.28% 96.61% Neck 93.38% 100.00% Total 266100.00% MBRBS = Multiple body regions or body systems.

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207 The results of the Levene test for homogeneity of variances of the injury severity scores did not allow for the assumption of equal variances, L (5, 258) = 8.14, p < 0.01. The results of the subsequent Welch robust test of equality of injury severity means showed a greater between body region group difference than within body region group difference in injury severity means among professional level workers, F (5, 54.34) = 3.41, p < 0.01. The Tukeys b range test was conducted to rank the six body regions injured among professionals according to their respective injury severity means. Figure 489 shows that among professionals neck injuries had the highest injury severity mean ( = 1.63). With an injury severity mean of = 1.53, injuries to multip le body parts or body regions ranked second among injuries to professionals. This was followed by in juries to the lower extr emities ( = 1.35), trunk ( = 1.35), upper extremities ( = 1.18), and head injuries ( = 1.11). From the arrangement of the homogeneous subsets shown in Figure 489, it was determined that there were significantly diffe rent injury severity means between the six body region groups, at p 0.05 (see Figure 490). Neck injuries had a significantly greater injury severity mean, at p 0.05, than injuries to the upper extremities and head. 1.63 (.74) 1.53 (.82) 1.35 (.59) 1.35 (.56) 1.18 (.44) 1.11 (.32)0.000.200.400.600.801.001.201.401.601.80Head (n = 36) Upper Extremities (n = 50) Trunk (n = 69) Lower Extremities (n = 71) Multiple Body Parts or Body Systems (n = 30) Neck (n = 8) Injury Severity Mean (Standard Deviation) Figure 489. Comparison of injury severity means by body region among professionals.

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208 1.63 (.74) 1.53 (.82) 1.35 (.59) 1.35 (.56) 1.18 (.44) 1.11 (.32)0.000.200.400.600.801.001.201.401.601.80Head (n = 36) Upper Extremities (n = 50) Trunk (n = 69) Lower Extremities (n = 71) Multiple Body Parts or Body Systems (n = 30) Neck (n = 8) Injury Severity Mean (Standard Deviation) Figure 490. Differences of injury severity means between body regions among professionals. Administrative Administrative level workers (n = 448) include d clerical workers (n = 253) and managers (n = 195). Table 460 shows slightly over 25% (n = 114) of the injuries to administrative level workers were to the trunk. Injuries to lower ex tremities accounted for over 24% (n = 108) of the injuries, followed by 23% (n = 105) injuries to the lower extremities, and 15% (n = 69) of the injuries to the head. Injuries to multiple body part s (n = 44) and neck injuries (n = 4) accounted for slightly more than 11% of the inju ries to administrative level workers. Table 460. Injuries to field admini strative level workers by body region. Body region Number of injuries % Cumulative % Trunk 11425.45% 25.45% Upper extremities 10824.11% 49.56% Lower extremities 10523.44% 72.99% Head 6915.40% 88.40% MBRBS* 449.82% 98.22% Neck 81.79% 100.00% Total 448100.00% MBRBS = Multiple body regions or body systems. The results of the Levene test for homogeneity of variances of the injury severity scores did not allow for the assumption of equal variances, L (5, 436) = 7.13, p < 0.01. The Welch test was conducted to examine if there was a statistica lly significant difference in injury severity

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209 means between the six body regions for injuries to administrative level workers. The results of this test showed at least one of the body regions displayed an injury severity mean that was significantly different from anot her body region for administrative level workers, F (5, 54.75) = 2.90, p < 0.03. The Tukeys b range test was conducted to id entify the specific di stribution of injury severity means between the six body region groups for administrative level workers (see Figure 491). Injuries to the neck had the highest inju ry severity mean ( = 1.57), followed by injuries to multiple body parts or body systems ( = 1.41), trunk ( = 1.35), head ( = 1.28), lower extremities ( = 1.20), and upper extremities ( = 1.12) No specific differences, significant at p 0.05, in injury severi ty means between the body regions among administrative level workers were found. 1.12 (.36) 1.20 (.49) 1.28 (.75) 1.35 (.77) 1.41 (.76) 1.57 (.79) 0.000.200.400.600.801.001.201.401.601.80 Upper Extremities (n = 106) Lower Extremities (n = 104) Head (n = 68) Trunk (n = 113) Multiple Body Parts or Body Systems (n = 44) Neck (n = 7) Injury Severity Mean (Standard Deviation) Figure 491. Comparison of injury severi ty means by body region among administrative workers. Head Injuries Body Part Information regarding head injuries by sp ecific body parts injured was provided for 7,539 worker injuries. Table 461shows that eye injuri es constituted over 60% (n = 4,776) of all head

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210 injuries. Soft tissue injuries, which pertain primarily to cuts or bruises to areas such as the check, scalp, eyebrows and forehead, accounted for almo st 18% of the head injuries (n = 1,342). Injuries to the mouth (n = 327) accounted for sligh tly less than five % of the head injuries while injuries to the teeth (n = 279), ears (n = 252), and nose (n = 199) each comprised around three % of all the head injuries. Facial bone injuries (n = 145), multiple head injuries (n = 91), skull injuries (n = 91), and injuries to the brain (n = 37) combined to account for less than five % of the head injuries. A comparison of injury means was conducted between the ten body parts. An assumption of equal variances of injury sc ores could not be made for the ten body parts for head injuries, L (9, 7,417) = 187.27, p < 0.001. The results of the subsequent Welch test of equality of injury severity means showed that, among head inju ries, at least one of the body parts had a significantly different injury severity mean than one of the other body parts, F (9, 451.63) = 32.41, p < 0.001. This was confirmed by the results of the Tukeys b range test (see Figure 492). Table 461. Head injuries by body part. Body region Number of injuries % Cumulative % Eye 4,77663.35% 63.35% Soft tissue 1,34217.80% 81.15% Mouth 3274.34% 85.49% Teeth 2793.70% 89.19% Ear 2523.34% 92.53% Nose 1992.64% 95.17% Facial bones 1451.92% 97.09% Multiple injuries 911.21% 98.30% Skull 911.21% 99.51% Brain 370.49%100.00% Total 7,539100.00% The rankings of body parts for head injuries by their descending injury severity mean magnitudes are shown in Figure 492. Brain injuries ha d the highest injury severity mean ( =

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211 2.22), followed by multiple head injuries ( = 1.64), injuries to the skull ( = 1.33), facial bones ( = 1.28), ears ( = 1.24), and soft tissue injuries ( = 1.22). Injuries to the nose had the seventh largest injury severity mean ( = 1.18), followed by injuries dire ctly impacting the teeth ( = 1.11), and mouth ( = 1.11). Eye injuries showed the lowest injury severity mean ( = 1.05). 1.05 (.27) 1.11 (.38) 1.11 (.38) 1.18 (.46) 1.22 (.50) 1.24 (.49) 1.28 (.56) 1.33 (.52) 1.64 (1.09) 2.22 (1.16) 0.000.501.001.502.002.50 Eye(s) (n = 4,709) Mouth (n = 322) Teeth (n = 279) Nose (n = 193) Soft Tissue (n = 1,315) Ear(s) (n = 248) Facial Bones (n = 144) Skull (n = 90) Multiple Head Injuries (n = 90) Brain (n = 37) Injry Severity Mean (Standard Deviation) Figure 492. Comparison of injury severity means by body part of head. From the homogeneous subsets of injury severi ty means for each of the body parts for head injuries, specific differences in inju ry severity means, significant at p 0.05, were discerned between the body parts among head injuries (seeF igure 493). Among head injuries, brain injuries showed a significantly gr eater injury severity mean, at p 0.05, than all of the remaining nine body parts. Multiple head injuries had a si gnificantly greater injury severity mean, at p 0.05, than skull injuries, injuries to the facial bones, ears, soft tissue, nose, teeth, mouth, and eyes. Skull injuries had a greater injury severity mean than injuri es to the nose, teeth, mouth and eyes. Facial bone injuries showed a si gnificantly higher injury severity mean, p 0.05, than

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212 injuries directly impacting the teeth, eyes, and mouth. Ear injuries and so ft tissue injuries each had significantly greater injury severity means, p 0.05, than eye injuries. 2.22 (1.16) 1.64 (1.09) 1.33 (.52) 1.28 (.56) 1.24 (.49) 1.22 (.50) 1.18 (.46) 1.11 (.38) 1.11 (.38) 1.05 (.27) 0.000.501.001.502.002.50 Eye(s) (n = 4,709) Mouth (n = 322) Teeth (n = 279) Nose (n = 193) Soft Tissue (n = 1,315) Ear(s) (n = 248) Facial Bones (n = 144) Skull (n = 90) Multiple Head Injuries (n = 90) Brain (n = 37) Injry Severity Mean (Standard Deviation) Figure 493. Differences of injury severity means between injured body parts of the head. Nature of Injury Information regarding the nature of head in juries was provided for 7,010 worker injuries. As Table 462 shows, a Foreign body was the natu re of the head injury for almost 54% (n = 3,781) of these cases. Lacerations (n = 1,259) accounted for just under 18% of the head injuries. Contusion (n = 623) accounted for almost nine % of the head injury cases. Inflammations (n = 329), burns (n = 310), and fractures (n = 299), accounted for nearly 5 % of the injuries to the head. Injury frequencies among the 21 remaini ng nature of injury categories combined to represent slightly more than five % of the h ead injuries. These include d the following: punctures (n = 79), concussions (n = 60), hear ing loss or impairment (n = 55), in fections (n = 45), strains (n = 36), enucleations (n = 28), multiple head in juries (n = 25), dermatitis (n = 15), other occupational diseases not otherwise classified (NOC) (n= 13), respiratory disorders (n= 11), crushing (n = 7), dislocations (n = 7), mental stress or mental diso rders (n = 7), sprains (n = 5),

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213 electric shocks (n = 4), general poisoning (n = 3) ruptures (n = 3), heat prostration (n = 2), chemical poisoning (n = 2), severance (n = 1), and syncope (n = 1). Table 462. Nature of head injuries. Nature of injury Number of injuries % Cumulative % Foreign body 3,78153.94%53.94% Laceration 1,25917.96%71.90% Contusion 6238.89%80.79% Inflammation 3294.69%85.48% Burn 3104.42%89.90% Fracture 2994.27%94.17% Puncture 791.13%95.30% Concussion 600.86%96.15% Hearing loss or impairment 550.78%96.94% Infection 450.64%97.58% Strain 360.51%98.09% Enucleation 280.40%98.49% Multiple Injuries 250.36%98.85% Dermatitis 150.21%99.06% Occupational disease NOC 130.19%99.25% Respiratory disorder 110.16%99.40% Crushing 70.10%99.50% Dislocation 70.10%99.60% Mental stress/disorder 70.10%99.70% Sprain 50.07%99.77% Electric Shock 40.06%99.83% Poisoning NOC 30.04%99.87% Rupture 30.04%99.92% Heat prostration 20.03%99.95% Chemical poisoning 20.03%99.97% Severance 10.01%99.99% Syncope 10.01%100.00% Total 7,010100.00% A comparison of the injury severity means for head injuries was made between the Nature of Injury classifications. The results of Levene test of homogeneity of severity scores between the nature of injury for head in juries did not allow for an assu mption of equal variances, L (24, 6,883) = 66.44, p < 0.001. Because syncope injuries and severance injuries to the head had only one case each and each had a zero injury sever ity score variance, the Welch robust test of equality of injury severity means for head inju ries between Nature of Injury groups could not

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214 be performed. The results of an ANOVA test did suggest that at least one of the Nature of Injury groups had a significantly different sever ity mean than one of the other classifications, F (24, 6,883) = 31.90, p < 0.001. When syncope and severance in juries were excluded, because of the inability to analyze frequencies fewer than tw o cases, the results of the Tukeys b range test confirmed the results of the ANOVA test. The results of the Tukeys b ra nge test are shown in Figure 494. Crushing head injuries had the highest injury severity mean ( = 2.86) among the head injuries. This was followed by mental stress and mental disorders ( = 1.86), sprains ( = 1.80), ruptures ( = 1.67), hearing loss or impairment ( = 1.64), concussions ( = 1.61), multiple injuries ( = 1.54), chemical poisoning ( = 1.50), heat prostration ( = 1.50), and strains ( = 1.31). The injury severity means declined steadily among the remaining nature of injury categories, ending with a severity of 1.00 for general poisoning. Severance and syncope injuries to the head each had a single case, thus were not included in the Tukeys range test. The severance injury had a severity score of two, equivalent to a temporary injury, while the case of syncope was reported at level three, corresponding to a permanent partial disability of some type. The remaining 25 Nature of Injury groups were compared using the Tukeys b range test (see Fi gure 495). Among the head injuries, crushing injuries had a significantly higher severity mean, at p 0.05, than all of th e other Nature of Injury groups. Mental stress or mental disorder s showed a significantly greater injury severity mean, at p 0.05, than head injuries from electric shock, fractures, contusions, punctures, respiratory disorders, lacerations, burns, in fections, other occupa tional diseases NOC, inflammation, dermatitis, foreign body, and general poisoning. Sprains had significantly greater injury severity mean, at p 0.05, than the same classifications as mental stress and mental

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215 disorders, except electric shocks and fractures. Ru pture injuries to the h ead had a significantly greater severity mean, at p 0.05, than head injuries invol ving a Foreign body and general poisoning. Hearing loss or impair ments showed a significantly greater severity mean, at p 0.05, than head injuries of general poisoning. 1.00 (0.00) 1.03 (.24) 1.07 (.27) 1.08 (.30) 1.08 (.28) 1.11 (.31) 1.13 (.40) 1.15 (.46) 1.15 (.43) 1.18 (.40) 1.19 (.60) 1.19 (.47) 1.22 (.49) 1.25 (.50) 1.29 (.49) 1.31 (.58) 1.50 (.71) 1.50 (.71) 1.54 (.59) 1.61 (.64) 1.64 (.59) 1.67 (1.15) 1.80 (.84) 1.86 (.69) 2.86 (2.03) 0.000.501.001.502.002.503.00 Poisoning General (n = 3) Foreign Body (n= 3733) Dermatitis (n = 14) Inflammation (n = 317) All Other Occupational Disease NOC (n = 13) Enucleation (n = 28) Infection (n = 45) Burn (n = 308) Laceration (n = 1241) Respiratory Disorders (n = 11) Puncture (n = 79) Contusion (n = 610) Fracture (n = 297) Electric Shock (n = 4) Dislocation (n = 7) Strain (n = 36) Heat of Prostration (n = 2) Poisoning Chemical (n = 2) Multiple Injuries (n = 24) Concussion (n = 59) Hearing Loss or Impairment (n = 53) Rupture (n = 3) Sprain (n = 5) Mental Stess/Disorder (n = 7) Crushing (n = 7) Injury Severity Mean (Standard Deviation) Figure 494. Comparison of injury severity means by nature of injury to the head.

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216 2.86 (2.03) 1.86 (.69) 1.80 (.84) 1.67 (1.15) 1.64 (.59) 1.61 (.64) 1.54 (.59) 1.50 (.71) 1.50 (.71) 1.31 (.58) 1.29 (.49) 1.25 (.50) 1.22 (.49) 1.19 (.47) 1.19 (.60) 1.18 (.40) 1.15 (.43) 1.15 (.46) 1.13 (.40) 1.11 (.31) 1.08 (.28) 1.08 (.30) 1.07 (.27) 1.03 (.24) 1.00 (0.00) 0.000.501.001.502.002.503.00 Poisoning General (n = 3) Foreign Body (n= 3733) Dermatitis (n = 14) Inflammation (n = 317) All Other Occupational Disease NOC (n = 13) Enucleation (n = 28) Infection (n = 45) Burn (n = 308) Laceration (n = 1241) Respiratory Disorders (n = 11) Puncture (n = 79) Contusion (n = 610) Fracture (n = 297) Electric Shock (n = 4) Dislocation (n = 7) Strain (n = 36) Heat of Prostration (n = 2) Poisoning Chemical (n = 2) Multiple Injuries (n = 24) Concussion (n = 59) Hearing Loss or Impairment (n = 53) Rupture (n = 3) Sprain (n = 5) Mental Stess/Disorder (n = 7) Crushing (n = 7) Injury Severity Mean (Standard Deviation) Figure 495. Differences of injury severity by nature of head injury. General Cause of Injury Information regarding the gene ral cause of head injuries was provided for 7,226 worker injuries. Table 462 shows that foreign matter in the eyes (n = 4,064) was attributed as the general cause of the injury for over 56% of the head injuries. Being struck by an object (n =

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217 1,433) was sited as the general cause of nearly 20% of the head in juries, while striking against or stepping on an object accounted for 6% of the injuries. Each of the remaining eight causes of injuries accounted for less than 5% of the head injuries. Table 462. Head injuries by general cause of injury. General cause of injury Number of injuries % Cumulative % Foreign matter 4,06456.24% 56.24% Struck by 1,43319.83% 76.07% Striling against or stepping on 4676.46% 82.53% Fall or slip 3574.94% 87.47% Cut, puncture, or scrape 2793.86% 91.34% Burn or Scald 2773.83% 95.17% Absorption, ingestion or inhalation 1231.70% 96.87% Strain 761.05% 97.92% Animal or insect bite or sting 761.05% 98.97% Motor vehicle 420.58% 99.56% Caught in or between 320.44% 100.00% Total 7,226100.00% The results following tests conducted to compar e the head injury severity means for the different general causes of injury are shown in Figure 496 and Figure 497. The results of the Levene test of homogeneity of h ead injury score variances between the general causes of injury did not allow an assumption of equal variances, L (10, 7,110) = 152.60, p < 0.001. Subsequently, the Welch test was performed to examine the equality of head injury severity means between general causes of injury. The result s of this test showed that at least one of the general causes of injury had a significantly different severity mean than one of the other general causes of injury, F (10, 382.41) = 27.51, p < 0.001. This was confirmed by the results of the Tukeys b range test. Rankings of the general causes of head injury by their respective severity means generated of the Tukeys b range test are displayed in Figure 496. Head in juries of being Caught in or between an object or objects had the highest severity mean ( = 1.41) followed falls or slips ( = 1.38), and events involving a motor vehicle ( = 1.37). Among the eleven causes of head injuries, head injuries involving strains had the f ourth highest severity m ean ( = 1.22), followed

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218 by being struck by an object ( = 1.19), having struck against or stepped on an object ( = 1.18), and being burned or scalded ( = 1.16), cut, punctured or scraped ( = 1.09), and being bitten by an animal or insect ( = 1.08). The remaining cause s were associated with injury severity means of less than 1.10. 1.04 (.24) 1.07 (.25) 1.08 (.32) 1.09 (.34) 1.16 (.47) 1.18 (.49) 1.19 (.52) 1.22 (.41) 1.37 (.58) 1.38 (.68) 1.41 (.61) 0.000.200.400.600.801.001.201.401.60 Foriegn Matter In Eye(s) (n = 4012) Absorption, Ingestion or Inhalation (n = 118) Animal or Insect Bite/Sting (n = 75) Cut, Puncture, or Scrape (n = 277) Burn or Scald (n = 274) Striking Against or Stepping On (n = 460) Struck By (n = 1406) Strain (n = 74) Motor Vehicle (n = 41) Fall or Slip (n = 352) Caught In or Between (n = 32) Injury Severity Mean (Standard Deviation) Figure 496. Comparison of injury severity means by general cause of head injury. A further examination of the homogeneous seve rity mean groupings of head injuries by general causes of injuries identified the specific difference of severity means, significant at p 0.05, between the twelve general causes of injury. The results of the assessment are displayed in Figure 497. Head injuries caused by being Caug ht in or between an object, falling or slipping, and a motor vehicle had a si gnificantly greater, at p 0.05, severity mean for head injuries than all of the remaining causes of injury. Head injuri es caused by some type of straining activity had

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219 a significantly higher injury severity mean, at p 0.05, than head injuries caused by foreign matter in the eyes. 1.41 (.61) 1.38 (.68) 1.37 (.58) 1.22 (.41) 1.19 (.52) 1.18 (.49) 1.16 (.47) 1.09 (.34) 1.08 (.32) 1.07 (.25) 1.04 (.24) 0.000.200.400.600.801.001.201.401.60 Foriegn Matter In Eye(s) (n = 4012) Absorption, Ingestion or Inhalation (n = 118) Animal or Insect Bite/Sting (n = 75) Cut, Puncture, or Scrape (n = 277) Burn or Scald (n = 274) Striking Against or Stepping On (n = 460) Struck By (n = 1406) Strain (n = 74) Motor Vehicle (n = 41) Fall or Slip (n = 352) Caught In or Between (n = 32) Injury Severity Mean (Standard Deviation) Figure 497. Differences of injury severity m eans between the general causes of head injury. Occupational Work Area Head injuries were examined by the workers occupational work areas at the time of the injury. Head injury by occupational work area information was provided for 6,019 injuries (see Table 463). Over 30% of the head injuries were reported for workers working in the area of carpentry (n = 932, 15.48%) and in iron and steel wo rk (n = 930, 15.45%). Slightly over 12% of the head injuries were among electrical worker s (n = 753). Each of the following work areas were associated with five and eight % of the h ead injuries: pipe fitting or pipe laying (n = 478, 7.94%), boilermakers (n = 367, 6.10%), and concrete work (n = 308, 5.12%). The remaining 35 occupational work areas (see Tabl e 4-63) were each accountable for less than 5% of the injuries.

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220 Table 463. Head injuries by occupational work area. Occupational work area Number of injuries % Cumulative % Carpentry 93215.48% 15.48% Iron/Steel 93015.45% 30.93% Electrical 75312.51% 43.44% Pipe fitting/laying 4787.94% 51.38% Boilermaker 3676.10% 57.48% Concrete 3085.12% 62.60% Welding 2834.70% 67.30% Plumbing 2754.57% 71.87% Technical repair and maintenance 2554.24% 76.10% Sheet metal 2534.20% 80.31% Equipment/machinery operation 1873.11% 83.41% Masonry 1472.44% 85.86% Millwright work 1292.14% 88.00% Painting 911.51% 89.51% Supervision 761.26% 90.77% Steam fitting 701.16% 91.94% Insulation 540.90% 92.84% Drywall Installation 500.83% 93.67% Driving 450.75% 94.41% Glazing 380.63% 95.04% Lineman 380.63% 95.68% Clerical 360.60% 96.27% Managing 330.55% 96.82% Sprinkler fitting 280.47% 97.29% Roofing 220.37% 97.65% Inspection 200.33% 97.99% Scaffold erection 180.30% 98.28% Engineering 160.27% 98.55% Conveyor systems work 130.22% 98.77% Security 130.22% 98.98% Lathing 120.20% 99.18% Material handling 90.15% 99.33% Waterproofing 90.15% 99.48% Flooring, tile, carpeting 70.12% 99.60% HVAC/refrigeration 60.10% 99.70% Rigging 50.08% 99.78% Landscaping 40.07% 99.85% Acoustic ceiling 30.05% 99.90% Surveying 30.05% 99.95% Field engineering 20.03% 99.98% Hod carrying 10.02% 100.00% Total 6,019100.00%

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221 Head injury severity means were compared between occupational work areas for which frequencies exceeded two injuries. The Welch robust test of equality of head injury severity means could not be performed over all of the occupational areas because at least one of the work areas had a head injury severity score varian ce of zero. In lieu of the Welch test, the ANOVA test was performed. The results of an ANOVA in dicated that at least one of the general occupational work areas could have had a significantly different h ead injury severity mean of one of the other occupati onal areas, F (38, 5,919) = 12.75, p < 0.001. This was not confirmed by the results of the Tukeys b range test. Figure 498 shows the rankings of the occupational work areas, by descending magnitudes of severity means for head injuries, generated by the Tukeys b test. The results of this did not indicate th at any of the occupational work areas had a significantly different head injury severity mean, at p 0.05, than any of the other work areas. Occupational work areas were ranked by head injury severity mean s (see Figure 498). Among the occupational work areas, injuries to workers in security showed had the highest severity mean ( = 1.38) for head injuries This was followed by supervision ( = 1.32), managing ( = 1.31), roofing ( = 1.29), and fl ooring, tile, or carpeting work ( = 1.29). Occupational work areas associated with head in juries with the lowest five severity means included material handling, acoustic ceiling wo rk, landscaping, HVAC and refrigeration work, and working with conveyor systems, each with injury severity means of = 1.00. Occupational Experience Level Head injuries were examined by workers general occupational experience level. Information regarding this relationship was pr ovided for 1,996 work injuries (see Table 464). Laborers had the highest frequency of head injuri es (n = 1,044) comprising over 50% of all of the head injuries. Apprentice leve l workers accounted for almost 13% of the head injuries (n = 259), while both journeymen level workers (n = 187) and foremen (n = 181) each accounted for

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222 over nine % of the injuries to th e head. Injuries to helper or assistant level workers (n = 142) accounted for seven % of the head injuries, follo wed by field supervisory level workers (n = 78, 3.91%), administrative level work ers (n = 69, 3.46%), and profe ssional workers. (n = 36, 1.80%). 1.00 (.00) 1.00 (.00) 1.00 (.00) 1.00 (.00) 1.00 (.00) 1.00 (.00) 1.03 (.17) 1.04 (.20) 1.06 (.25) 1.07 (.31) 1.07 (.38) 1.08 (.32) 1.08 (.33) 1.08 (.30) 1.08 (.29) 1.08 (.39) 1.08 (.36) 1.09 (.35) 1.10 (.29) 1.10 (.39) 1.11 (.41) 1.11 (.37) 1.11 (.32) 1.13 (.38) 1.14 (.39) 1.14 (.38) 1.15 (.37) 1.16 (.68) 1.17 (.52) 1.18 (.39) 1.20 (.45) 1.22 (.55) 1.25 (.46) 1.25 (.73) 1.29 (.49) 1.29 (.56) 1.31 (.78) 1.32 (.90) 1.38 (.51) 0.000.200.400.600.801.001.201.401.60 Conveyor Systems Work (n = 13) HVAC/Refrigeration (n = 6) Landscaping (n = 4) Acoustic Ceiling Installation (n = 3) Material Handling (n = 9) Surveying (n = 3) Steam Fitting (n = 70) Drywall Installtion (n = 50) Engineers (n = 16) Sheet Metal Work (n = 251) Sprinkler Fitting (n = 27) Pipe Fitting (n = 476) Welding (n = 279) Plumbing (n = 273) Lathing (n = 12) Iron/Steel Work (n = 920) Boilermaker (n = 365) Insulation (n = 54) Masonry (n = 146) Millwright (n = 129) Electrical Work (n = 740) Concrete Work (n = 306) Glazing (n = 36) Carpentry (n = 924) Equipment/Machine Operation (n = 184) Painting/Plastering (n = 91) Inpsecting (n = 20) Lineman (n = 38) Technician (n = 252) Driving (n = 45) Rigging (n = 5) Scaffold Erection (n = 18) Waterproofing (n = 8) Clerical (n = 36) Flooring/Tile/Carpeting (n = 7) Roofing (n = 21) Managing (n = 32) Supervising (n = 76) Security (n = 13) Injury Severity Mean (Standard Deviation) Figure 498. Comparison of injury severity means by occupational work area of workers with a head injury.

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223 Table 464. Head injuries by occupational experience level. Occupational experience level Numb er of injuries % Cumulative % Laborer 1,04452.30% 52.30% Apprentice 25912.98% 65.28% Journeyman 1879.37% 74.64% Foreman 1819.07% 83.71% Helper/assistant 1427.11% 90.83% Field supervisor 783.91% 94.73% Administrative 693.46% 98.19% Professional 361.80% 100.00% Total 1,996100.00% The severity means of head injuries was co mpared between occupational experience levels. The result of the Levene test did not permit the assumption of equal severity score variances between the eight occupati onal levels, L (7, 1,963) = 13.34, p < 0.001. Subsequently, the results of the Welch test of equality of head injury severity means between the eight experience level groups showed that at least one of the experience levels had a significantly different head injury severity mean than one of the other experience levels, F (7, 289.66) = 3.64, p < 0.01. This was confirmed by the results of the Tukeys range test as illustrated in Figure 499. The Tukeys b tests the ranking of occupati onal experience levels by their descending head injury severity mean magnitudes, along with the homogeneous subsets of severity means, are shown in Figure 499. Among general occupati onal experience levels, the most severe head injuries were to field supervisors ( = 1.32) and administrative personnel ( = 1.28). With an injury severity mean of 1.13, laborers showed the third most severe experience level for head injuries. This was followed by head injuries to foremen ( = 1.12), pr ofessionals ( = 1.11), apprentices ( = 1.11), helpers or assistants ( = 1.10), and journeymen ( = 1.09). Figure 4100 shows the occupational experience levels that ha d significantly different severity means, at p 0.05, for head injuries.

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224 1.09 (.30) 1.10 (.30) 1.11 (.39) 1.11 (.32) 1.12 (.45) 1.13 (.40) 1.28 (.75) 1.32 (.90) 0.000.200.400.600.801.001.201.40 Journeyman (n = 185) Helper/Assistant (n = 140) Apprentice (n = 258) Professional (n = 36) Foreman (n = 178) Laborer (n = 1030) Administrative (n = 68) Field Supervision (n = 76) Injury Severity Mean (Standard Deviation) Figure 499. Comparison of injury severity means by occupational experi ence level of workers with head injuries. Head injuries to field supervisors showed a significantly greater severity mean, at p 0.05, than all of the other occupational experience le vels, except administrators. Head injuries to administrative personnel showed a signi ficantly higher severity means, at p 0.05, than head injuries to helpers or assistants and journeymen (see Figure 4100). 1.32 (.90) 1.28 (.75) 1.13 (.40) 1.12 (.45) 1.11 (.32) 1.11 (.39) 1.10 (.30) 1.09 (.30) 0.000.200.400.600.801.001.201.40 Journeyman (n = 185) Helper/Assistant (n = 140) Apprentice (n = 258) Professional (n = 36) Foreman (n = 178) Laborer (n = 1030) Administrative (n = 68) Field Supervision (n = 76) Injury Severity Mean (Standard Deviation) Figure 4100. Differences of injury severity between occupational experien ce levels of workers with head injuries.

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225 Age Age often indicates differential ri sk that can be used to target injury control efforts. An examination of the influence of the age of workers on head injuries was conducted. The results of the Levene test for homogeneity of variances of the ages did not allow for the assumption of equal variances, L (9, 2,366) = 2.37, p 0.01. The results of the subsequent Welch test of the homogeneity of variances of ages by the 10 body re gion categories for head injuries showed that at least one of the specific body parts displayed a mean age that was significantly different than one of the body parts, F (5, 77.98) = 5.43, p < 0.01. This was confirmed by the results of the Tukeys b range test. The Tukeys b range test was conducted to iden tify the specific dist ribution of age means between the ten body parts for head injuries (see Fi gure 4101). Injuries to the ears showed the highest mean age, 42.86 years. This was followed by multiple head injuries ( = 39.61), injuries to the nose ( = 38.84), brain ( = 38.50), soft tissue ( = 37.05), facial bones ( = 36.91), eyes ( = 36.51), skull ( = 35.50), mout h ( = 34.02), and teeth ( = 32.88). 32.88 (8.48) 34.02 (10.30) 35.50 (11.05) 36.51 (10.78) 36.91 (10.80) 37.05 (10.93) 38.50 (10.89) 38.84 (12.85) 39.61 (10.40) 42.86 (12.30) 05101520253035404550 Teeth (n = 86) Mouth (n = 123) Skull (n = 10) Eye(s) (n = 1,532) Facial Bones (n = 32) Soft Tissue (n = 418) Brain (n = 6) Nose (n = 50) Multiple Head Injuries (n = 31) Ear(s) (n = 88) Mean Age (Standard Deviation) Figure 4101. Comparison of mean ages by body part of the head injured.

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226 A further examination of the arrangement of the homogeneous subsets of the age means showed that, among head injuries, injuries to the ears had a significantly higher mean age, at p 0.05, than injuries that directly impacted the teeth. No other si gnificantly different means, at p 0.05, were displayed between the body parts among head injuries (see Figure 4102). 42.86 (12.30) 39.61 (10.40) 38.84 (12.85) 38.50 (10.89) 37.05 (10.93) 36.91 (10.80) 36.51 (10.78) 35.50 (11.05) 34.02 (10.30) 32.88 (8.48) 05101520253035404550 Teeth (n = 86) Mouth (n = 123) Skull (n = 10) Eye(s) (n = 1,532) Facial Bones (n = 32) Soft Tissue (n = 418) Brain (n = 6) Nose (n = 50) Multiple Head Injuries (n = 31) Ear(s) (n = 88) Mean Age (Standard Deviation) Figure 4102. Differences of mean ag es by body parts of the head injured. Injury severity means for head injuries were examined by age. The results of the Levene test of homogeneity of injury score variances for the six age groups did not allow for an assumption of equal variances, L (5, 2,334) = 6.89, p < 0.001. The results of the Welch test showed that none of the age groups had a significantly different inju ry severity mean than any of the other age groups, F (5, 254.66) = 1.48, p > 0.19. This was confirmed by the results of the Tukeys b range test (see Figure 4103). At p 0.05, the results of the Tukeys b test did not show significantly different injury severity means between the age groups for head injuries. As Figure 4103 shows, workers between the ages of 60 to 69 years had the high est injury severity mean ( = 1.17), followed by

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227 workers between 50 and 59 years of age ( = 1.1 4), 40 and 49 years of age ( = 1.11), under 20 years old ( = 1.10), and workers between 30 and 39 years of age ( = 1.09). Workers between 20 and 29 years old had the lowest injury severi ty mean, = 1.08. 1.08 (.31) 1.09 (.33) 1.10 (.30) 1.11 (.37) 1.14 (.46) 1.17 (.44) 1.021.041.061.081.101.121.141.161.181.20 20 29 (n = 674) 30 39 (n = 717) Under 20 (n = 51) 40 -49 (n = 550) 50 59 (n = 302) 60 69 (n = 46) Injury Severity Mean (Standard Deviation) Figure 4103. Comparison of injury severity means by age of workers with head injuries. Month of Occurrence of Injury Head injuries were examined relative to th e month of the year during which the injury occurred. Information regarding the month in which head injuries occurred were provided for 7,539 worker injuries. Table 465 shows that head injuries occurred in October for slightly over 10% (n = 764) of all the head injuries. August had the second hi ghest relative frequency of head injuries (n = 682, 9.05%). With between 612 and 662 reported head injuries, the months of January, March, April, May, July, September, and November each accounted for slightly over eight % of the head injuries. Around seven % of the head injuries occurred in either June (n = 556), December (n = 550), or February (n = 511). Following the results of the Le vene test, L (11, 5,442) = 18.7, p < 0.05, no assumption of equal variances of head injury severity scor es could be made among the twelve months. The Welch test of equality of severity means for head injuries showed that none of the months of the year had a significantly different head injury seve rity mean with any of the other months, F (11,

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228 1,893.46) = 0.54, p > 0.80. This observation was further confirmed by the results of the Tukeys b range test. Table 465. Head injuries by month of occurrence. Month of injury Number of injuries % Cumulative % October 76410.13% 10.13% August 6829.05% 19.18% November 6628.78% 27.96% September 6578.71% 36.67% July 6528.65% 45.32% March 6428.52% 53.84% May 6308.36% 62.19% January 6218.24% 70.43% April 6128.12% 78.55% June 5567.37% 85.92% December 5507.30% 93.22% February 5116.78% 100.00% Total 7,539100.00% Rankings of the months of the year by their respective head injury severity means were generated by the Tukeys b range and are illustrated in Figure 4104. Head injuries occurring during December had the highest severity mean ( = 1.15), followed by the months of November ( = 1.13), September ( = 1.13), June ( = 1.13), February ( = 1.13), July ( = 1.13), and May ( = 1.13). Head injuries which occurred within the months of March ( = 1.12), January ( = 1.12), August ( = 1.11), October ( = 1.10) and April ( = 1.10) were associated with the five lowest severity means. All months were found to constitute a single homogeneous group which indicates that, at p 0.05, no specific significant head injury severity mean differences were found between any of the months. Day of the Week of Occurrence of Injury Head injuries were examined relative to the day of the week during which the injury occurred. Information regarding the month in which head injuries occurred were provided for

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229 7,539 worker injuries. Table 466 shows that he ad injuries occurred most frequently on Wednesdays (21% of all injuries, n = 1,592). This was followed closely by Tuesdays (n = 1,536) with slightly over 20% of the head injuries. Thursdays (n = 1, 470) and Mondays (n = 1,449) each were associated with just under 20% of the h ead injuries. Among the days within a business week, the day attributed to having the least am ount of head injuries was Friday (n = 1,333, 17.68%). Among the seven calendar days of the week, Saturdays (n = 124, 1.64%) and Sundays (n = 35, 0.46%) showed the smallest nu mber of head injury occurrences. 1.10 (.33) 1.10 (.41) 1.11 (.37) 1.12 (.42) 1.12 (.39) 1.13 (.42) 1.13 (.50) 1.13 (.42) 1.13 (.41) 1.13 (.41) 1.13 (.45) 1.15 (.48) 1.071.081.091.101.111.121.131.141.151.16 April (n = 449) October (n = 433) August (n = 448) January (n = 995) March (n = 462) May (n = 417) July (n = 432) February (n = 365) June (n = 427) September (n = 478) November (n = 312) December (n = 236) Injury Severity Mean (Standard Deviation) Figure 4104. Comparison of injury severity m eans by month of occurrence of head injuries. Table 466. Head injuries by the day of the week of occurrence. Day of the week Number of injuries % Cumulative % Wednesday 1,592 21.12% 21.12% Tuesday 1,536 20.37% 41.49% Thursday 1,470 19.50% 60.99% Monday 1,449 19.22% 80.21% Friday 1,333 17.68% 97.89% Saturday 124 1.64% 99.54% Sunday 35 0.46% 100.00% Total 7,539100.00%

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230 Head injury severity means fo r each day of the week were compared. The results of the Levene test did not allow for an assumption of equal head inju ry severity scores variances, among the seven days of the week, L (6, 5,447) = 2.34, p < 0.03. The results of the Welch test of equality of head injury severi ty means showed that there was greater within days of week differences of severity means than between days of week differences of injury severity, F (6, 1,587.43) = 0.54, p > 0.70. The Tukeys b range test was conducted in or der to both rank the days of week by their respective head injury severity means and to dete ct any specific signifi cant differences of head injury severity means, at p 0.05, between the days of the week. Figure 4105 shows that head injuries which were reported to have occurred on Saturdays had the high est severity means for head injuries ( = 1.14). Among typical workweek days, injuries on Fridays had the highest injury severity mean ( = 1.14). Among all th e days of the week, Mondays ( = 1.12), Wednesdays ( = 1.12), and Tuesdays ( = 1.12), we re associated with third, fourth, and fifth highest, respectively, severity m eans for head injuries. Thursdays ( = 1.11) and Sundays ( = 1.11) showed the lowest head injury severity mean s. The results of the Tu keys range test also showed that there were no significantly different injuries severity means, at p 0.05, for head injuries between any of the days of the week. This confirmed by the results of the Welch test. 1.11 (.43) 1.11 (.35) 1.12 (.41) 1.12 (.38) 1.12 (.42) 1.14 (.43) 1.14 (.52) 1.081.091.101.111.121.131.141.15 Sunday (n = 264) Thursday (n = 688) Tuesday (n = 850) Wednesday (n = 812) Monday (n = 1866) Friday (n = 554) Saturday (n = 420) Injury Severity Mean (Standard Deviation) Figure 4105. Comparison of injury severity m eans by the day of the w eek of occurrence of head injuries.

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231 Neck Injuries The frequency and severity of neck injuries were examined in relation to the demographic variables of age, job tenure prio r to the injury event, month of the injury, and day of the week during which the injury occurr ed. Similar examinations were conducted for the specific body part of the neck that was injured, the nature of the injury, and the general cause of the injury, the general occupational experience level of the injure d worker at the time of the injury, and the specific occupational work area in which the inju red worker was working at the time of the neck injury. Body Part Frequency i nformation regarding the specific body pa rt affected by the neck injury was provided for 985 workers and is displayed in Ta ble 467. Over 65% of these neck injuries affected the soft tissue (n = 648). Some type of injury to the di scs within the neck region were associated with nearly 19% (n = 187) of the neck injuries. An injury to multiple parts of the neck accounted for almost eight % (n = 78) of the neck injuries. Spinal chord (n = 40, 4.06%) and vertebrae (n = 29, 2.94%) neck injuries combined for seven % of all the neck injuries. Less than one % of the neck injuries affected the larynx (n = 3). Table 467. Neck injuries by body part injured. Body part Number of injuries % Cumulative % Soft tissue 64865.79% 65.79% Disc 18718.98% 84.77% Multiple injuries 787.92% 92.69% Spinal cord 404.06% 96.75% Vertebrae 292.94% 99.70% Larynx 30.30% 100.00% Total 985100.00% Neck injury severity means were compared be tween the six body parts. The results of the Levene test of equal severity score variances between the six body parts of the neck indicated

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232 that the assumption of equal variance could not be assumed, L (5, 958) = 6.59, p < 0.001. Subsequently, the results of the Welch test indicated that at least one of the body parts of the neck had a significantly different injury severity mean than one of the other body parts, F (5, 20.47) = 14.88, p < 0.001. This was confirmed by the result s of the Tukeys b range test (see Figure 4103and Figure 4107). Using the Tukeys b range test, the six body parts of the neck were ranked by their respective injury severity means (see Figure 4106). Injury to th e neck vertebrae had the highest injury severity mean ( = 2.07), followed by disc injuries ( = 1.87) injuries to the larynx ( = 1.67), injury to spinal chord area of the neck ( = 1.53), and multiple neck injuries ( = 1.38). Injuries to the soft tissue of the neck had the lowest severi ty mean ( = 1.34). The Tukeys b range test identi fied homogeneous subsets of injury severity means among the six neck body parts. Significantly different severity means, at p 0.05, were discerned between the six body parts of the neck (see Fi gure 4107). Among neck injuries, vertebral injuries had a significantly grea ter injury severity mean, at p 0.05, than soft tissue injuries of the neck. 1.34 (.61) 1.38 (.56) 1.53 (.85) 1.67 (.58) 1.87 (.81) 2.07 (.88) 0.000.501.001.502.002.50 Soft Tissue (n = 631) Multiple Neck Injuries (n = 78) Spinal Cord (n = 40) Larynx (n = 3) Disc (n = 183) Vertebrae (n = 29) Injury Severity Mean (Standard Deviation) Figure 4106. Comparison of injury severity means by body part of the neck injured.

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233 2.07 (.88) 1.87 (.81) 1.67 (.58) 1.53 (.85) 1.38 (.56) 1.34 (.61) 0.000.501.001.502.002.50 Soft Tissue (n = 631) Multiple Neck Injuries (n = 78) Spinal Cord (n = 40) Larynx (n = 3) Disc (n = 183) Vertebrae (n = 29) Injury Severity Mean (Standard Deviation) Figure 4107. Differences of injury severity means between injured body parts of the neck. Nature of Injury Based on information provided for 893 neck in juries, the distributi on of injuries was assessed for each of the 21 nature of injury categories (see Table 468). Almost 61% of the all neck injuries were strains (n = 542). Ruptures accounted for slightly under nine % (n = 79) of the injuries to the neck, and 66 contusions account ed for seven %. This was followed by neck sprains (n = 56, 6.27%), inflammations (n = 35, 3 .92%), punctures (n = 24, 2.69%), fractures (n = 22, 2.46%), burns (n = 20, and lacerations of the neck (n = 18, 2.02%). The relative frequencies of the remaining 13 nature of injury classifications combined to account for slightly more than three % of all the neck injuries. Thes e included multiple neck injuries (n = 7), hernia (n = 6), dislocations (n = 4), infections (n = 2) severances (n = 2), asphyxiation (n = 2), other occupational diseases NOC (n = 2), a concussi on, one crushing, one electric shock injury, a single Foreign body case, a general poisoning, and a single case of dermatitis of the neck. Neck injury severity means were compared be tween the nature of injury classifications. Nature of injury groups with a frequency of one were excluded from this comparison. In addition dislocations and occupational diseases NOC each had a zero severity score variance the Welch robust test of equality of means could not be performed. The results of the ANOVA test

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234 suggested that at least on e of the nature of injury groups had a neck injury severity mean that was significantly different from one of th e other categories, F (15, 852) = 126.94, p < 0.001. This was confirmed by the results of the Tukeys b range test. Table 468. Neck injuries by nature of injury Nature of injury Number of injuries % Cumulative % Strain 54260.69% 60.69% Rupture 798.85% 69.54% Contusion 667.39% 76.93% Sprain 566.27% 83.20% Inflammation 353.92% 87.12% Puncture 242.69% 89.81% Fracture 222.46% 92.27% Burn 202.24% 94.51% Laceration 182.02% 96.53% Multiple injuries 70.78% 97.31% Hernia 60.67% 97.98% Dislocation 40.45% 98.43% Infection 20.22% 98.66% Severance 20.22% 98.88% Asphyxiation 20.22% 99.10% Occupational disease NOC 20.22% 99.33% Concussion 10.11% 99.44% Crushing 10.11% 99.55% Electric shock 10.11% 99.66% Foreign body 10.11% 99.78% Poisoning NOC 10.11% 99.89% Dermatitis 10.11% 100.00% Total 893100.00% The results of the Tukeys b range test for e quality of severity means for neck injuries between the nature of injury cat egories are shown in Figure 4108. Ruptures resulted in neck injuries with the highest injury severity mean ( = 2.51), followed closely by severances ( = 2.50), and neck fractures ( = 2.41). Occupational di seases NOC and dislocations each had neck injury severity means of = 2.00, but with no va riance. Neck injuries of asphyxiation ( = 1.50), infections ( = 1.50), and hernias ( = 1.50) ha d the sixth, seventh, and eighth, respectively,

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235 highest severity means for neck injuries among the nature of injury groups. The nature of injury categories associated with the lo west eight neck injury sever ity means included sprains ( = 1.47), contusions ( = 1.44), multiple neck injuri es ( = 1.43), strains ( = 1.37), inflammation ( = 1.12), lacerations ( = 1.11), punctures ( = 1.08), and burns ( = 1.05). Two homogeneous subsets of neck injury severity means by nature of injury categories were detected with the Tukeys b test. Nature of injury categories within each subset had neck injury severity means that did not significantly differ, at p 0.05, from one of the other ca tegories within the subset. From the arrangement of the two subsets s hown in Figure 4108 it was determined that ruptures, severances, and fractures of the neck ha d significantly higher injury severity means, at p 0.05, than inflammations, lacerations, punctures, and burns to the neck (see Figure 4109). 1.05 (.72) 1.08 (.28) 1.11 (.47) 1.12 (.41) 1.37 (.63) 1.43 (.53) 1.44 (.76) 1.47 (.60) 1.50 (.71) 1.50 (.71) 1.50 (.55) 2.00 (0.00) 2.00 (0.00) 2.41 (1.01) 2.50 (.71) 2.51 (.53) 0.000.501.001.502.002.503.00 Burn (n = 20) Puncture (n = 24) Laceration (n = 18) Inflammation (n = 34) Strain (n = 532) Multiple Injuries (n = 7) Contusion (n = 61) Sprain (n = 55) Hernia (n = 6) Infection (n = 2) Asphyxiation (n = 2) Dislocation (n = 3) Occupational Disease NOC (n = 2) Fracture (n = 22) Severence (n = 2) Rupture (n = 78) Injury Severity Mean (Standard Deviation) Figure 4108. Comparison of injury severi ty means by nature of neck injury.

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236 2.51 (.53) 2.50 (.71) 2.41 (1.01) 2.00 (0.00) 2.00 (0.00) 1.50 (.55) 1.50 (.71) 1.50 (.71) 1.47 (.60) 1.44 (.76) 1.43 (.53) 1.37 (.63) 1.12 (.41) 1.11 (.47) 1.08 (.28) 1.05 (.72) 0.000.501.001.502.002.503.00 Burn (n = 20) Puncture (n = 24) Laceration (n = 18) Inflammation (n = 34) Strain (n = 532) Multiple Injuries (n = 7) Contusion (n = 61) Sprain (n = 55) Hernia (n = 6) Infection (n = 2) Asphyxiation (n = 2) Dislocation (n = 3) Occupational Disease NOC (n = 2) Fracture (n = 22) Severence (n = 2) Rupture (n = 78) Injury Severity Mean (Standard Deviation) Figure 4109. Differences of injury seve rity means by nature of neck injuries. General Cause of Injury Nine general causes of neck in juries were determined based on information provided for 985 worker injuries. Table 469 shows the distribu tion of neck injury fr equencies by the general cause of the injury. Straining was the leading cau se of neck injuries (n = 347, 36.22%), followed by struck by injuries (n = 183, 19.10 %). Slightly more than 15% (n = 148) of the neck injuries were caused by the worker striking against or ste pping on an object or objects. Just over ten % of the neck injuries were caused by a slip or fall (n = 99). Some kind of involvement with a motor vehicle was cited as the cause of injury for around eight % (n = 77) of the neck injuries. Just over three % (n = 32) of the neck injuries were cause d by a bite or sting of an animal or insect. Absorption, inhalation, or ingestion of a substanc e (n = 26) along with being cut, punctured or scraped by an object (n = 20), and being burned (n = 19) accounted for around 2 % eah, of the

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237 neck injuries. Less than one % of neck injuries (n = 7) were caused by the worker being Caught in or between an object or objects. Table 469. General cause of neck injuries. General cause of injury Number of injuries % Cumulative % Strain 34736.22% 36.22% Struck by 18319.10% 55.32% Striling against or stepping on 14815.45% 70.77% Fall or slip 9910.33% 81.11% Motor vehicle 778.04% 89.14% Animal or insected bite or sting 323.34% 92.48% Absorption, ingestion or inhalation 262.71% 95.20% Cut, puncture, or scrape 202.09% 97.28% Burn 191.98% 99.27% Caught in or between 70.73%100.00% Total 958100.00% Despite the results of the Levene test of homogeneity of n eck injury severity scores between the cause of injury groups (L (9, 927) = 20.71, p < 0.001), the Welch test of equality of means could not be performed because neck injuries caused by Absorption, ingestion or inhalation of a substance showed zero variance of the severity score. Consequently, the ANOVA test was used in lieu of the Welch test to asse ss differences of severity mean between the general causes of neck injuries. The resu lts of the ANOVA test showed that at least one of the causes of neck injuries might have a neck injury severity mean significantly different than one of the other general cause of injury ca tegories, F (9, 927) = 6.08, p < 0.001. As Figure 4110 and Figure 4111 illustrate, this result was confirmed by the results of the Tukeys b range test. The results of the Tukeys b range test demonstr ated that neck injuries from falls or slips are associated with the highest in jury severity mean ( = 1.61). Falls and slips, as a general cause of injury, was followed by straining as causing n eck injuries with the second highest severity mean ( = 1.59). This was followed by neck injuri es caused by involvement with a motor vehicle ( = 1.51), being struck by an object ( = 1.47), ha ving struck against or stepped on an object (

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238 = 1.35), having been cut, punctured or scraped by an object ( = 1.25), Caught in or between an object or objects ( = 1.14), burned ( = 1.11), and having been bitten or stung by an animal or insect ( = 1.03). Neck injuries caused by the ab sorption, ingestion, or inhalation of a substance had the lowest severi ty mean ( = 1.00). 1.00 (0.00) 1.03 (.18) 1.11 (.32) 1.14 (.38) 1.25 (.55) 1.35 (.58) 1.47 (.70) 1.51 (.91) 1.59 (.73) 1.64 (.74) 0.000.200.400.600.801.001.201.401.601.80 Absorption, Ingestion or Inhalation (n = 26) Animal or Insect Bite/Sting (n = 31) Burn (n = 19) Caught In or Between (n = 7) Cut, Puncture, or Scrape (n = 20) Striking Against or Stepping On (n = 146) Struck By (n = 177) Motor Vehicle (n = 77) Strain (n = 339) Fall or Slip (n = 95) Injury Severity Mean (Standard Deviation) Figure 4110. Comparison of injury severity means by general cause of neck injuries. Specific neck injury severity mean differences between the nine general causes of injury were discerned for the homogeneous subset s shown in Figure 4110. As Figure 4111 illustrates, neck injuries from falls or slip s had a significantly higher severity mean, at p 0.05, than neck injuries from either being bitten or st ung by an animal or insect or from the absorption, ingestion or inhalation of a s ubstance. In addition, neck inju ries caused by straining had a significantly greater inju ry severity mean, at p 0.05, than neck injuries from the absorption, inhalation, or ingestion of a substance. 1.64 (.74) 1.59 (.73) 1.51 (.91) 1.47 (.70) 1.35 (.58) 1.25 (.55) 1.14 (.38) 1.11 (.32) 1.03 (.18) 1.00 (0.00) 0.000.200.400.600.801.001.201.401.601.80 Absorption, Ingestion or Inhalation (n = 26) Animal or Insect Bite/Sting (n = 31) Burn (n = 19) Caught In or Between (n = 7) Cut, Puncture, or Scrape (n = 20) Striking Against or Stepping On (n = 146) Struck By (n = 177) Motor Vehicle (n = 77) Strain (n = 339) Fall or Slip (n = 95) Injury Severity Mean (Standard Deviation) Figure 4111. Differences of injury severity means between general causes of neck injury.

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239 Occupational Work Area Neck injury frequency information regardi ng the occupational work area in which the injured worker was working at the time of the n eck injury was provided for 743 worker injuries. These frequencies are displayed in Table 4 70. Carpentry workers experienced over 15% (n = 118) of the neck injuries, followed by electrical workers (n = 99, 13.32%), and workers involved in iron and steel work (n = 93, 12.52%). Technicians experienced around nine % (n = 65) of the injuries to the neck, while pipe fitting (n = 48) and concrete workers (n = 43) each accounted for around six % of the neck injuries. Around three % of the neck injuries were to workers working in either plumbing (n = 29), equipment or mach inery operation (n = 28), or masonry (n = 22). Workers working as or with a boilermaker (n = 19), in painting or plastering (n = 17), sheet metal work (n = 17), welding (n = 16), or supervisory work (n = 16) accounted for slightly more than 2 % each of the neck injuries Drivers had nearly two % (n = 14) of the neck injuries, while workers conducting some type of inspection work had just above one % (n = 8) of the neck injuries. The remaining work areas shown Table 470 were associated with less than one % of the neck injuries. Among neck injuries, injury severity means we re compared between each of the workers general occupational work areas. Th e results of the Leven test of homogeneity of neck injury severity scores by the general occupational work area did not support an assumption of equal variances, L (29, 695) = 2.57, p < 0.001. However, The Welch test of equality of neck injury severity means between the work areas could no t be performed because the following work areas had a variance of injury severity scores equa l to zero: Flooring, til e, or carpeting, rigging, Acoustic ceiling work, flagging, security, mate rial handling, surveying, field engineering, managing, engineering, landscaping, and glaz ing. Consequently, the ANOVA test was performed to assess possible differences of neck injury severity means between the work areas.

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240 The results of the ANOVA test di d not show a significant between work areas severity mean difference than within work areas differences, F (29, 695) = 18.27, p > 0.18. The Tukeys b range test was conducted in order to rank the oc cupational work areas by their respective neck injury severity means (see Figure 4 112). The results of the Tukeys also confirmed the ANOVA the results. None of the work areas had a significantly different n eck injury severity Table 470. Neck injuries by occupational work area of injured workers. Occupational work area Number of injuries % Cumulative % Carpentry 118 15.88% 15.88% Electrical 99 13.32% 29.20% Iron/Steel 93 12.52% 41.72% Technical repair and maintenance 65 8.75% 50.47% Pipe Fitting/laying 48 6.46% 56.93% Concrete 43 5.79% 62.72% Plumbing 29 3.90% 66.62% Equipment/machinery operation 28 3.77% 70.39% Masonry 22 2.96% 73.35% Boilermaker 19 2.56% 75.91% Painting and plastering 17 2.29% 78.19% Sheet metal 17 2.29% 80.48% Welding 16 2.15% 82.64% Supervision 16 2.15% 84.79% Driving 14 1.88% 86.67% Millwright work 13 1.75% 88.42% Lineman 11 1.48% 89.90% Drywall Work 10 1.35% 91.25% Inspecting 8 1.08% 92.33% Steam fitting 7 0.94% 93.27% Clerical 7 0.94% 94.21% Roofing 6 0.81% 95.02% Insulation 5 0.67% 95.69% Scaffold erection 5 0.67% 96.36% HVAC/Refrigeration 4 0.54% 96.90% Glazing 3 0.40% 97.31% Sprinkler fitting 3 0.40% 97.71% Landscaping 3 0.40% 98.11% Conveying systems 2 0.27% 98.38% Lathing 2 0.27% 98.65% Flooring, tile, or carpeting 1 0.13% 98.79% Rigging 1 0.13% 98.92% Acoustic ceiling work 1 0.13% 99.06% Flagging Traffic 1 0.13% 99.19% Security 1 0.13% 99.33% Material handling 1 0.13% 99.46% Surveying 1 0.13% 99.59% Field engineering 1 0.13% 99.73% Managing 1 0.13% 99.86% Engineering 1 0.13% 100.00% Total 743 100.00%

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241 mean, at p 0.05, than any of the other work areas. In order to conduct the Tukeys any work area with a neck injury frequenc y of less than two was excluded. 1.00 (.00) 1.19 (.40) 1.20 (.45) 1.21 (.42) 1.25 (.50) 1.29 (.47) 1.29 (.59) 1.33 (.58) 1.33 (.71) 1.33 (.52) 1.36 (.50) 1.39 (.63) 1.40 (.71) 1.41 (.67) 1.41 (.64) 1.43 (.53) 1.44 (.69) 1.47 (.74) 1.50 (.71) 1.50 (.71) 1.52 (.71) 1.53 (.83) 1.57 (.79) 1.60 (.55) 1.62 (.87) 1.63 (.74) 1.68 (.94) 1.76 (.87) 1.79 (.80) 2.00 (0.00) 0.000.501.001.502.002.50 Landscaping (n = 3) Supervising (n = 16) Scaffold Erection (n = 5) Boilermaker (n = 19) HVAC/Refrigeration (n = 4) Painting/Plastering (n = 17) Sheet Metal Work (n = 17) Sprinkler Fitting (n = 3) Drywall Installation (n = 9) Roofing (n = 6) Lineman (n = 11) Equipment or Mashinery Operation (n = 28) Pipe Fitting (n = 48) Masonry (n = 22) Electrical Work (n= 99) Steam Fitting (n = 7) Technician (n = 64) Welding (n = 15) Conveyor Systems Work (n = 2) Lathing (n = 2) Carpentry (n = 115) Concrete Work (n = 43) Clerical (n = 7) Insulation (n = 5) Millwright (n = 13) Inspection (n = 8) Plumbing (n = 28) Iron/Steel Work (n = 92) Driving (n = 14) Glazing (n = 3) Injury Severity Mean (Standard Deviation) Figure 4112. Comparison of injury severity m eans by occupational work area of workers with neck injuries. Of all the work areas which had two or mo re cases, workers performing a glazing activity at the time of injury had the hi ghest neck injury se verity mean ( = 2.00). This was followed by

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242 driving ( = 1.79), iron and stee l work ( = 1.76), plumbing ( = 1.68), inspecting ( = 1.63), and working with or as a millwright ( = 1.62). Insulation workers had the seventh highest neck injury severity mean ( = 1.60), followed by clerical work ( = 1.57), concrete work ( = 1.53) carpentry ( = 1.52). The remaining twenty occu pational work areas, and their respective neck injury severity means, are found in Figure 4112, which shows a single homogeneous subset identified from the Tukeys b test. This indicat es no significant neck injury severity mean difference, at p 0.05, between the general occupational work areas. Occupational Experience Level Neck injury distributions by th e workers level of occupational experience are displayed in Table 471. Information regard ing neck injuries among occupa tional experience levels was provided for 307 worker injuries. Laborers experienced just over 50% (n = 157) of the neck injuries. Journeymen (n = 37) and apprentice leve l workers (n = 36) each represented nearly 12% of the 307 neck injuries. Foremen experienced ju st under 10% (n = 9.45%) of the neck injuries, followed by field supervisors not otherwise classified (n = 17) and helpers or assistants (n = 14). Professionals (n = 9) and administrative personne l (n = 8) had less than 3 % each of the neck injuries. The eight occupational experience levels were compared by their resp ective neck injury severity means. The results of the Levene test did not allow for an assumption of equal variances of neck injury severity scores between th e occupational experience levels, L (7, 294) = 3.60, p < 0.002. Subsequently, the Welch robust test of equality of neck inju ry severity means between the eight experience levels was performed. The results for this test indicated that none of the occupational experience levels had a significantly different severity mean for neck injuries from any of the other experien ce levels, F (7, 42.48) = 1.743, p > 0.10. This was confirmed by the results of the Tukeys b range test (see Figure 4113).

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243 Table 471. Neck injuries by occupational experience level. Experience Level Number of injuries % Cumulative % Laborer 15751.14% 51.14% Journeyman 3712.05% 63.19% Apprentice 3611.73% 74.92% Foreman 299.45% 84.36% Field supervision 175.54% 89.90% Helper/assistant 144.56% 94.46% Professional 92.93% 97.39% Administrative 82.61% 100.00% Total 307100.00% Figure 4113 shows the rankings, by neck in jury severity mean, for each of the eight occupational experience levels. Homogenous grou pings of experience levels in which no significant difference of neck injury severity mean, at p 0.05, is shown between any group members is depicted by the sing le transparent recta ngular box. Profession als had the highest severity mean of neck injuries ( = 1.63), fo llowed by neck injuries to administrative level workers ( = 1.57), laborers ( = 1.57), foreme n ( = 1.45), journeymen ( = 1.38), apprentices ( = 1.37),and helpers and assistan ts ( = 1.31), Field supervisors not otherwise classified had the lowest neck injury severity mean ( = 1.19). Despite these ra nkings, the Tukeys b range test did not detect significan tly different neck injury severity means, at p 0.05, between any of the occupational experience levels. 1.19 (.40) 1.31 (.48) 1.37 (.55) 1.38 (.55) 1.45 (.63) 1.57 (.75) 1.57 (.79) 1.63 (.74) 0.000.200.400.600.801.001.201.401.601.80 Field Supervision (n = 16) Helper/Assistant (n = 13) Apprentice (n = 35) Journeyman (n = 37) Foreman (n = 29) Laborer (n = 157) Administrative (n = 7) Professional (n = 8) Injury Severity Mean (Standard Deviation) Figure 4113. Comparison of injury severity means by occupational experience levels of workers with neck injuries.

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244 Age From a previous analysis, the mean age of workers with neck injuries ( = 38.56) was significantly greater, at p 0.05, than that for workers with lo wer extremity injuries ( = 37.00) and head injuries ( = 36.68). Information regard ing neck injuries and th e respective age, by age group, was provided for 317 worker in juries. Table 472 shows workers' neck injury frequencies by four age groups. Workers between the ages of 30 and 39 years (n = 97) and 40 through 49 years (n = 97) represented just over 30% each of the neck injuries. Workers between 20 and 29 years of age had almost 23% (n = 72) of the neck injuries, and 16% of the neck injuries were to workers between the ages of 50 and 59 years. Table 472. Neck injuries by age. Age (year) Number of injuries % Cumulative % 30 39 9730.60% 30.60% 40 49 9730.60% 61.20% 20 29 7222.71% 83.91% 50 59 5116.09% 100.00% Total 317100.00% Injury severity means for neck injuries we re compared by age groups in which workers with neck injuries were assigned. The results of the Levene test did not allow for an assumption of equal neck injury severity score variances between the four age groups, L (3, 307) = 12.74, p < 0.001. The Welch test was subsequently performe d in order to detect any significant neck injury severity mean differences between the age gr oups. The results of this test indicated that at least one of the age groups had a significantly diffe rent neck injury severity mean than one of the other age groups, F (3, 151.73) = 6.17, p < 0.002. The results of the Tukeys b range confirmed this result. The results of the Tukeys b range test enab led the ranking of age groups by neck injury severity mean (see Figure 4114). Workers between 50 and 59 years of age had the highest

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245 severity mean for neck injuri es ( = 1.55), followed by workers 40 through 49 years old ( = 1.48), and between 30 and 39 years of age ( = 1.43). Workers 20 through 29 years of age had the lowest neck injury severi ty mean ( = 1.17). Figure 4 114 also shows the grouping of age groups by the homogeneity of their respective neck injury severity means, at p 0.05. 1.17 (.48) 1.43 (.63) 1.48 (.74) 1.55 (.70) 0.000.200.400.600.801.001.201.401.601.80 20 29 Years Old (n = 71) 30 39 Years Old (n = 95) 40 49 Years Old (n = 94) 50 59 Years Old (n = 51) Injury Severity Mean (Standard Deviation) Figure 4114. Comparison of injury severity m eans by age of workers with neck injuries. From the arrangement of the two homogeneous subsets of the neck in jury severity means among the four age groups, it was determined that the neck injury seve rity means for the 30 through 39, 40 through 49, and 50 through 59 years ol d workers were significantly greater, at p 0.05, than the neck injury severity mean for work ers within the 20 to 29 years of age group. This is illustrated in Figure 4115. 1.55 (.70) 1.48 (.74) 1.43 (.63) 1.17 (.48) 0.000.200.400.600.801.001.201.401.601.80 20 29 Years Old (n = 71) 30 39 Years Old (n = 95) 40 49 Years Old (n = 94) 50 59 Years Old (n = 51) Injury Severity Mean (Standard Deviation) Figure 4115. Differences between injury severity means by age of workers with neck injuries.

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246 A comparison of age means, by specific body part injured, was conducted for neck injuries. There was only a single case where age (age = 38) was reported for neck injuries to the larynx. Groups with only one case were ignored in computing the Levene test of homogeneity of variance for age between th e specific neck body parts. The results of the Levene test allowed for an assumption of equal variances, L (4, 311) = 0.65, p > 0.60. The results of the subsequent ANOVA test showed that there were no significant differences of mean age between the specific body parts for neck injuries, F (5, 311) = 1.71, p > 0.10. Figure 4116 shows the rankings, by mean age, of the specific body parts injured among neck injuries. Injuries to disc of the neck showed the highest mean age ( = 40.79), followe d by neck injuries to the soft tissue ( = 38.63), multiple neck injuries ( = 37.00), and spin al chord injuries ( = 35.60). Injuries to the vertebrae of the neck displayed the lowest mean age ( = 27.75). 27.75 (6.65) 35.60 (10.98) 37.00 (11.24) 38.63 (9.87) 40.70 (9.53) 01020304050 Vertebrae (n = 4) Spinal Chord (n = 15) Multiple Neck Injuries (n = 15) Soft Tissue (n = 238) Disc (n = 44) Injury Severity Mean (Standard Deviation) Figure 4116. Comparison of mean ag es by body part of neck injuries. Job Tenure Job tenure was examined for data on neck injuries. Information regarding these two dimensions was provided for 777 worker injuries. Table 473shows the distribution of neck injuries by job tenure. Just over 18% (n = 141) of these cases occurred to workers who had been working 91 to 180 days prior to experiencing th eir neck injuries. Around 15% (n = 120) of the neck injuries were experienced between the 81st and 365th day of employment. Neck injuries

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247 occurring within the first 90 days employment combined to account for nearly 46% (n = 354) of the neck injuries. Around 21% of the neck injuries occurred afte r the first year of employment. Table 473. Injury frequency by job te nure of workers with neck injuries. Job tenure Number of injuries % Cumulative % 91 to 180 days 14118.15% 18.15% 81 to 365 days 12015.44% 33.59% 31 to 60 days 10513.51% 47.11% 0 to 15 days 8811.33% 58.43% 16 to 30 days 8210.55% 68.99% 61 to 90 days 7910.17% 79.15% 366 to 730 days (1 to 2 years) 7810.04% 89.19% 731 to 1,460 days (2 to 4 years) 445.66% 94.86% > 1,461 days (> 4 years) 405.15% 100.00% total 777100.00% Injury severity for neck injuries was explor ed by workers job tenure on the date of the injury. The results of the Levene test of homogeneity of neck injury severity score variances between nine job tenure categor ies allowed for the assumption of equal variances, L (8, 752) = 1.03, p > 0.40. Subsequently, the results of the ANOV A did not show any significant difference of neck injury severity means between the nine job tenure categor ies, F (8, 752) = 0.36, p > 0.90. This was confirmed by the results of the T ukeys b range test (s ee Figure 4 117). 1.39 (.68) 1.45 (.60) 1.48 (.67) 1.50 (.66) 1.52 (.65) 1.53 (.77) 1.53 (.78) 1.54 (.71) 1.57 (.70) 1.301.351.401.451.501.551.60 > 1461 Days (> 4 Years) (n = 38) 366 to 730 Days (1 to 2 Years) (n = 76) 31 to 60 Days (n = 101) 731 to 1460 Days (2 to 4 Years) (n = 44) 16 to 30 Days (n = 81) 91 to 180 Days (n = 137) 61 to 90 Days (n = 79) 181 to 365 Days (n = 119) 0 to 15 Days (n = 86) Injury Severity Mean (Standard Deviation) Figure 4117. Comparison of injury severity mean s by job tenure of workers with neck injuries.

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248 The results of the Tukeys b range test indicated that all of the neck injury severity means for the nine job tenure groups were homogeneous, th us showing no significantly different neck injury severity means, at p 0.05, between any of the job tenure categories. Despite the lack of any significant diffe rence of neck injury severity means between the job tenure periods, each of thes e were ranked by their respective neck injury severity mean (see Figure 4117). Neck inju ries occurring within the first 15 days of employment had the highest severity mean ( = 1.57). This was followed closely by workers with neck injuries o ccurring between the 181st and 365th day of employment ( = 1.54), the 61st and 90th day ( = 1.53), the 91st and 180th day ( = 1.53), and the 6th and 30th day of employment ( = 1.52). Workers who had been working two to f our years prior to expe riencing a neck injury had the fourth lowest injury severity mean ( = 1.50), followed by job tenure periods of 31 to 60 days ( = 1.48), and one to two years ( = 1.45). Workers with over four years job tenure prior to reporting a neck injury had the lowest severity mean ( = 1.39) associated with those neck injuries. Month of Occurrence of Injury The month of the year during which neck injuries occurred was examined, based on information provided for 985 worker injuries. Tabl e 474 shows that over ten % (n = 101) of the neck injuries occurred during th e month of August. During each of the months of September (n = 94), November (n = 94), and June (n = 91), sli ghtly over nine % of the neck injuries occurred. Around 17% of these neck injuries were reported to have occurred du ring the months of July (n = 87) and May (n = 82). Each of the following mont hs were associated with slightly over seven % of the neck injuries: namely, January (n = 77), October (n = 77), February (n = 76), March (n = 75), and April (n = 74). December was associated with the least amount of neck injuries (n = 57, 5.79%).

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249 Table 474. Neck injuries by month of occurrence. Month of occurrence Number of injuries % Cumulative % August 10110.25% 10.25% September 949.54% 19.79% November 949.54% 29.34% June 919.24% 38.57% July 878.83% 47.41% May 828.32% 55.73% January 777.82% 63.55% October 777.82% 71.37% February 767.72% 79.08% March 757.61% 86.70% April 747.51% 94.21% December 575.79%100.00% Total 985100.00% Injury severity means were compared for neck injuries occurring in the twelve months of the year. Injury severity scores were provided for 964 of the 985 n eck injuries. The results of the Levene test of homogeneity of variances betw een the twelve months did not allow for an assumption of equal variances, L (11, 952) = 3.11, p < 0.001. The subsequent results of the Welch test of equality of neck injury severity means between the months of the year did not indicate any signifi cant differences, at p 0.05, of neck injury severity means between any of the months, F (11, 364.87) = 1.76, p > 0.05; however, this was not c onfirmed by the results of the Tukeys b range test. The results of the Tukeys b range test are illustrated in Figure 4118. Neck injuries occurring within the month of April had the highest severity mean ( = 1.67). April was followed by February ( = 1.59), October ( = 1. 54), and January ( = 1.53) as having the second, third, and fourth highest ne ck injury severity means. The injury severity means for the months of May, June, September, November, Augus t, and March showed a steady decline, with December having the lowest injury severity mean of = 1.25.

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250 1.25 (.51) 1.40 (.73) 1.42 (.59) 1.43 (.62) 1.45 (.63) 1.46 (.68) 1.48 (.77) 1.50 (.79) 1.53 (.68) 1.54 (.76) 1.59 (.85) 1.67 (.76) 0.000.200.400.600.801.001.201.401.601.80 December (n = 56) March (n = 72) August (n = 100) November (n = 91) September (n = 93) July (n = 85) June (n = 90) May (n = 82) January (n = 75) October (n = 74) February (n = 73) April (n = 73) Injury Severity Mean (Standard Deviation) Figure 4118. Comparison of injury severity m eans by month of occurrence of neck injuries. From the two homogeneous groupings of the months by neck injury severity means, it was determined that, at p 0.05, neck injuries that occurre d during the month April had a significantly greater severity mean than thos e which happened during December (see Figure 4119). 1.67 (.76) 1.59 (.85) 1.54 (.76) 1.53 (.68) 1.50 (.79) 1.48 (.77) 1.46 (.68) 1.45 (.63) 1.43 (.62) 1.42 (.59) 1.40 (.73) 1.25 (.51) 0.000.200.400.600.801.001.201.401.601.80 December (n = 56) March (n = 72) August (n = 100) November (n = 91) September (n = 93) July (n = 85) June (n = 90) May (n = 82) January (n = 75) October (n = 74) February (n = 73) April (n = 73) Injury Severity Mean (Standard Deviation) Figure 4119. Differences between injury seve rity means by month of occurrence of neck injuries.

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251 Day of the Week of Occurrence of Injury A similar investigation as the one conducted for month of occu rrence of the neck injuries was performed regarding the relationship betwee n neck injuries and the day of week on which injuries occurred. Information regarding the distribut ion of neck injuries re lative to the day of the week of injury occurrence was provided for 985 wo rker injuries. As Table 475 shows, nearly 60% of the 985 neck injuries occurred on Wedne sdays (n = 200), Thursdays (n = 196) and Tuesdays (n = 192). Slightly over 16% of the neck injuries were experienced on either Mondays (n = 166) or Fridays (n = 163). Slightly less than 5% of the neck injuries occurred on Saturdays (n = 44), and less than 3% occurred on Sunday (n = 24). Injury severity scores were provided for 964 neck injuries. Prior to comparing the neck injury severity means between the days of the week, the Leven test of homogeneity of severity score variances for the days of the week was perf ormed. The results of this test allowed for an assumption of equal variances (L (6, 957) =1.64, p > 0.10), thus prompting the use of an ANOVA to assess the possibility that any of the days of the week could have a significantly different neck injury severity mean from one of the other days. The results of the ANOVA indicated that none of the days of the week had a significantly di fferent neck injury severity mean than any of the other days of the week, F (6, 957) = 0.33, p > 0.90. This was confirmed by the results of the Tukeys b range test. Table 475. Neck injuries by da y of the week of occurrence. Day of the week of occurrence Nu mber of injuries % Cumulative % Wednesday 20020.30% 20.30% Thursday 19619.90% 40.20% Tuesday 19219.49% 59.70% Monday 16616.85% 76.55% Friday 16316.55% 93.10% Saturday 444.47% 97.56% Sunday 242.44%100.00% Total 985100.00%

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252 Figure 4120 was derived from the results of the Tukeys b range test for homogeneity of neck injury severity means by days of the week. The results of this test showed that the neck injury severity means for each day of the week were identified as a single homogeneous group, thus indicating that none of the days of the w eek had a neck injury severity mean that was significantly different, at p 0.05, from any of the other days of the week. Despite the outcome, the results also allowed for the ranking of the da ys of week by their resp ective severity mean for neck injuries. Neck injuries occurring on Saturdays ( = 1.52) and Fridays ( = 1.52) had the highest severity means. These were followe d by Tuesdays ( = 1.49), Mondays ( = 1.49), Thursdays ( = 1.47), and Wednesdays ( = 1.44). Neck injuries occurring on a Sunday had the lowest injury severity mean. 1.38 (.50) 1.44 (.64) 1.47 (.73) 1.49 (.68) 1.49 (.75) 1.52 (.70) 1.52 (.90) 1.301.351.401.451.501.55 Sunday (n = 21) Wednesday (n = 193) Thursday (n = 193) Monday (n = 162) Tuesday (n = 191) Friday (n = 160) Saturday (n = 44) Injury Severity Mean (Standard Deviation) Figure 4120. Comparison of injury severity m eans by day of the week of occurrence of neck injury. Trunk Injuries to the trunk region made up just over 25% (n = 11,646) of the injuries to the six body regions. Injuries to the trunk had a significantly greater injury severity mean ( = 1.44), at

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253 p 0.05, than injuries to the lower extremities ( = 1.40), lower extremities ( = 1.26), and head injuries ( = 1.11). Body Part Information on trunk injuries by the specifi c body part injured was provided for 11, 646 worker injuries. The distribution of trunk injuries by specific body pa rt is displayed in Table 476. Just over 48% (n = 5,611) of the trunk injuries were injuries to the lower back. Around 18% (n = 2,115) of the trunk injuries were to the shoulders. Injuries to the abdomen or groin (n = 1,144), chest (n = 882), lower back (n = 528), and lumb ar or sacral vertebrae (n = 431) combined to constitute almost 26% of the injuries to the trunk. Injuries to internal organs not otherwise classified (n = 328) and the lungs (n = 324) accounted for nearly three % each of the 11,646 trunk injuries. The remaining five trunk body part injuries constituted less than 3 % of the trunk injuries. Table 476. Trunk injuries by body part. Body part Number of injuries % Cumulative % Lower back 5,61148.18% 48.18% Shoulder 2,11518.16% 66.34% Abdomen (includes groin 1,1449.82% 76.16% Chest 8827.57% 83.74% Upper back 5284.53% 88.27% Lumbar and/or sacral Vertebrae 4313.70% 91.97% Internal organs NOC 3282.82% 94.79% Lungs 3242.78% 97.57% Multiple injuries 920.79% 98.36% Buttocks 690.59% 98.95% Heart 610.52% 99.48% Pelvis 330.28% 99.76% Sacrum and coccyx 280.24% 100.00% Total 11,646100.00% A comparison of the severity means was conduc ted between each of the thirteen body parts for trunk injuries. Injury severity scores, by body part, were provided for 11,490 of these trunk

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254 injuries. The results of the Levene test of hom ogeneity of trunk injury severity scores between the body parts did not allow for an assumpti on of equal variances L (12, 11,477) = 23.89, p > 0.001. The results of the subsequent Welch test of equality of trunk injury severity means between the body parts indicated th at at least one of the trunk body parts displayed a trunk injury severity mean that were different from one of the other body parts, F (12, 454.74) = 13.76, p < 0.001. This was not confirmed by the results of th e Tukeys b range test for injury severity means between specific body parts of the trunk. The results of the Tukeys b test allowed th e specific body parts of the trunk to be ranked according to their respective in jury severity means (see Figure 4121). Along with these rankings, Figure 4121 displays the five subsets of body pa rts by homogeneous trunk injury severity means. Heart injuries had the highest injury severity mean ( = 2.19) among trunk injuries. Pelvis injuries showed the second highest severity mean ( = 1.82) for trunk injuries. This was followed by multiple trunk injuries ( = 1.57), injuries to the abdomen (including the groin) ( = 1.54), shoulder injuries ( = 1.48), and injuries to the lower back ( = 1.44). Injuries or occupational diseases of the lungs ( = 1.44) had the seve nth highest severity mean among the trunk injuries. This was followed by injuries to the lumbar or sacral vertebrae ( = 1.40), internal organs not otherwise classified ( = 1.35), lower back ( = 1. 34), chest ( = 1.28), and buttocks ( = 1.28). Among trunk injuries, th ose to the sacrum and/or coccyx had the lowest severity mean ( = 1.25). Significantly different trunk injury severity means, at p 0.05, between body parts were discerned from the homogeneous subsets shown in Figure 4121. These ar e displayed in Figure 4122. Among injuries to the trunk, heart injuries had a significan tly greater severity mean, at p 0.05, than injuries to all of the other body parts. Injuries to the pe lvis had a severity mean that

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255 was significantly greater, at p 0.05, than all of the other body part s, except the heart. Injuries to the chest, buttocks, and sacrum or coccyx displayed a trunk inju ry severity mean significantly lower, at p 0.05, than that of multiple injuries to th e trunk. Abdomen (including groin) injuries had a significantly grea ter severity mean, at p 0.05, than injuries to the sacrum or coccyx 1.25 (.60) 1.28 (.51) 1.28 (.54) 1.34 (.61) 1.35 (.71) 1.40 (.60) 1.44 (.65) 1.44 (.62) 1.48 (.66) 1.54 (.63) 1.57 (.64) 1.82 (.81) 2.19 (1.26) 0.000.501.001.502.002.50 Sacrum & Coccyx (n = 28) Buttocks (n = 68) Chest (n = 853) Upper Back (n = 515) Internal Organs NOC (n = 327) Lumbar and/or Sacral Vertebrae (n = 428) Lungs (n = 320) Lower Back Area (n = 5544) Shoulders (n = 2093) Abdomen (includes Groin) (n = 1133) Multiple Trunk Injuries (n = 91) Pelvis (n = 33) Heart (n = 57) Injury Severity Mean (Standard Deviation) Figure 4121. Comparison of injury severi ty means by injured body parts of the trunk. 2.19 (1.26) 1.82 (.81) 1.57 (.64) 1.54 (.63) 1.48 (.66) 1.44 (.62) 1.44 (.65) 1.40 (.60) 1.35 (.71) 1.34 (.61) 1.28 (.54) 1.28 (.51) 1.25 (.60) 0.000.501.001.502.002.50 Sacrum & Coccyx (n = 28) Buttocks (n = 68) Chest (n = 853) Upper Back (n = 515) Internal Organs NOC (n = 327) Lumbar and/or Sacral Vertebrae (n = 428) Lungs (n = 320) Lower Back Area (n = 5544) Shoulders (n = 2093) Abdomen (includes Groin) (n = 1133) Multiple Trunk Injuries (n = 91) Pelvis (n = 33) Heart (n = 57) Injury Severity Mean (Standard Deviation) Figure 4122. Differences of injury severi ty means by injured body parts of the trunk.

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256 General Nature of Injury Information regarding the general nature of trunk injuries was provided for 11,646 worker injuries. Over 95% (n = 11,118) of the injuries to the trunk were specific injuries. Around four % (n = 456) of the trunk injuries were either an occupational disease or a cumulative disorder. Multiple injuries to the trunk constituted less than one % (n = 72) of the trunk injuries (see Table 477). Table 477. Trunk injuries by general nature of injury. General nature of injury Number of injuries % Cumulative % Specific injury 11,11895.47% 95.47% Occupational disease or cumulative injury 4563.92% 99.39% Multiple injuries 720.62% 100.00% Total 11,646100.00% From the 11,646 trunk injury cases, information regarding the injury severity relative to general nature of the trunk injury was provided for 11,490 worker injuries. The results of the Levene test of homogeneity of trunk injury seve rity scores between the three general nature of injury categories did not allow for the assumption of equal variances, L (2, 16.06, p < 0.001. Subsequently, the results of the Welch robust te st of equality of trunk injury severity means indicated that at least on e of the general nature of injury gr oups had a significantly greater trunk injury severity mean than one of th e other categories, F (2, 166.44) = 12.62, p < 0.001. This was confirmed by the results of the Tukeys b range test of trunk injury severity means between the three general nature of injury groups. From the results of the Tukeys b test, each of the general nature of injury classifications for trunk injuries was ranked by their respective injury severity means (see Figure 4123). Among trunk injuries, multiple injuries to the trunk had the highest severity mean ( = 1.65), followed by specific injuries to the trunk ( = 1.45). Occupational di seases or cumulative injuries to the trunk had the lowest severity mean ( = 1.32).

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257 From the two groupings of general nature of injury classifi cations by homogeneous severity means, it was determined that multiple trunk injuries had a significantly greater injury severity mean, at p 0.05 than that for both specific tr unk injuries and injuries to the trunk resulting from an occupational di sease or cumulative injury. This is illustrated in Figure 4124. 1.32 (.60) 1.45 (.64) 1.65 (.67) 0.000.501.001.502.00 Occupational Disease or Cummulative Injury (n = 439) Specific Injury (n = 10979) Multiple Injuries (n = 72) Injury Severity Mean (Standard Deviation) Figure 4123. Comparison of injury severity means by general nature of trunk injuries. 1.65 (.67) 1.45 (.64) 1.32 (.60) 0.000.501.001.502.00 Occupational Disease or Cummulative Injury (n = 439) Specific Injury (n = 10979) Multiple Injuries (n = 72) Injury Severity Mean (Standard Deviation) Figure 4124. Differences of injury severity means by general nature of trunk injuries. Nature of Injury Within each of the general nature of inju ry categories, specific Nature of Injury categories were identified. Information about the distribution of nature of trunk injuries was provided for 10,820 worker injuries (see Table 478). Strains comprised just over 69% (n = 7,503) of the injuries to the trunk. Contusions (n = 1,031) had the second highest frequency among trunk injuries (9.53%). Sprains (n = 457) and hernias (n = 374) accounted for around 4 % each, of the trunk injuries. The remaining 29 nature of injury categories accounted for less than 14% of the injuries.

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258 Nature of injury classifications of trunk inju ries with of less than two cases were excluded from subsequent trunk injury se verity means comparisons between the nature of injury groups. The single amputation among the trunk injuries ha d an injury severity score of two (i.e., temporary injury), while both the concussion, and carpal tunnel cases each had a severity score of one (i.e., medical only). The implausibility of a, concussion and carpal tunnel syndrome being associated with a trunk injury suggests the lik elihood of a miscode fo r each these respective cases. With the exception of the single cases of amputation, carpal tunnel syndrome, and concussion, the trunk injury severity means were generated for each of the nature of injury classifications. Comparisons between these mean s were subsequently co nducted. The results of the Levene test did not allow for an assumption of equal trunk injury severity score variances between the nature of injury gr oups. The Welch test of equality of means could not be conducted because there was a zero variance of severity sc ores for the Foreign body ( = 1.00), syncope ( = 1.00) and dermatitis ( = 1.00) nature of injury groups for trunk injuries. In lieu of the Welch test, an ANOVA test was performed to initially assess possible trunk injury severity mean differences between the nature of injury cat egories with a frequency of two or more. The results of the ANOVA indicated that at leas t one of the nature of injury groups had a trunk injury severity mean that was significantly di fferent from one of the other nature of injury groups, F (15, 852) = 22.40, p < 0.001. This was confirmed by the results of the Tukeys b range test of trunk injury severity means between the nature of injury groups. Using the results of the Tukeys b test each of the nature of injury groups was ranked by their severity means for trunk injuries (see Figu re 4125). Amputation, ca rpal tunnel syndrome, and concussion were excluded because the T ukeys b range test could not accommodate

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259 categories with less than two cases. Among the nature of injury categories for trunk injuries, myocardial infarction had the highest injury seve rity mean ( = 2.60). Silicosis was associated with trunk injuries with the sec ond highest injury severity mean ( = 2.50). The results of the Tukeys b test also generated homogeneous subsets of the nature of injury groups (see Figure 4125). Each column represents a set of nature of injury groups which have similar means. From this, specific differences between groups we re inferred, as displayed in Figure 4126. Table 478. Injury frequency by nature of trunk injury. Nature of injury Number of injuries % Cumulative % Strain 7,50369.34% 69.34% Contusion 1,0319.53% 78.87% Sprain 4574.22% 83.10% Hernia 3743.46% 86.55% Fracture 1711.58% 88.13% Asbestosis 1691.56% 89.70% Respiratory disorder 1621.50% 91.19% Rupture 1561.44% 92.63% Inflammation 1141.05% 93.69% Dislocation 1000.92% 94.61% Laceration 910.84% 95.45% Multiple Injuries 720.67% 96.12% Puncture 680.63% 96.75% Chemical poisoning 650.60% 97.35% Heat prostration 450.42% 97.76% Myocardial infarction 440.41% 98.17% Burn 430.40% 98.57% Occupational disease NOC 250.23% 98.80% Infection 210.19% 98.99% Poisoning NOC 160.15% 99.14% Asphyxiation 150.14% 99.28% Electric shock 140.13% 99.41% Crushing 130.12% 99.53% Dermatitis 110.10% 99.63% Angina pectoris 90.08% 99.71% Mental stress/disorder 80.07% 99.79% Severance 60.06% 99.84% Silicosis 60.06% 99.90% Foreign body 50.05% 99.94% Syncope 30.03% 99.97% Amputation 10.01% 99.98% Concussion 10.01% 99.99% Carpal tunnel syndrome 10.01% 100.00% Total 10,820100.00%

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260 1.00 (.00) 1.00 (.00) 1.00 (.00) 1.08 (.27) 1.18 (.45) 1.25 (.53) 1.27 (.53) 1.27 (.56) 1.30 (.58) 1.31 (.49) 1.34 (.69) 1.37 (.57) 1.37 (.57) 1.38 (.59) 1.41 (.61) 1.48 (.65) 1.62 (1.19) 1.63 (.52) 1.65 (.67) 1.76 (.72) 1.81 (.69) 1.84 (.69) 1.89 (1.27) 1.93 (.54) 2.00 (1.18) 2.23 (1.54) 2.33 (.52) 2.37 (.59) 2.50 (.55) 2.60 (1.35) 0.00 0.50 1.00 1.50 2.00 2.50 3.00 Foreign Body (n = 5) Syncope (n = 3)) Dermatitis (n = 11) Chemical Poisoning (n = 65) Heat of Prostration (n = 44) Asbestosis (n = 155) Contusion (n = 1004) Laceration (n = 88) Puncture (n = 67) General Poisoning (n = 16) Burn (n = 41) Inflammation (n = 112) Respiratory Disorders NOC (n = 160) Infection (n = 21) Strain (n = 7441) Sprain (n = 442) Asphyxiation (n = 13) Mental Stress/Disorder (n = 8) Multiple Injuries (n = 72) Occupational Disease NOC (n = 25) Fracture (n = 171) Dislocation (n = 100) Angina Pectoris (n = 9) Hernia (n = 373) Electric Shock (n = 14) Crushing (n = 13) Severance (n = 6) Rupture (n = 156) Silicosis (n = 6) Myocardial Infarction (n = 40) Injury Severity Mean (Standard Deviation) Figure 4125. Comparison of injury seve rity means by nature of trunk injuries.

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261 Among the trunk injuries, myocardial infarc tions had a significantly greater, at p 0.05, injury severity mean than all of the other nature of injury categories, exce pt silicosis, rupture, severance, crushing, electric shock, and hernia (see Figure 4126). Silicosis showed a similar difference as myocardial infarction, with the ex ception of angina pectoris, dislocation, and fracture. Ruptures displayed a similar set of di fferences to silicosis, with the exception of occupational diseases not otherwise classified (NOC) and multiple trunk injuries. Among trunk injuries, both severances and crushing had a signif icantly greater injury se verity mean than that for sprains, strains, infections, respirator y disorders NOC, inflammations, burns, general poisoning, punctures, lacerations, contusions, asbestosis, heat prostration, chemical poisoning, dermatitis, syncope, and a Foreign body. Electric s hock injuries to the trunk had a significantly greater severity mean, p 0.05, heat prostration, chemical poisoning, dermatitis, syncope, and Foreign body injuries to the trunk. Hernias displayed a significantly higher injury severity mean, at p 0.05, than chemical poisoning, dermatitis relate d, syncope, and foreign body injuries to the trunk region. Fractures to body parts of the trunk ha d a significantly greater injury severity mean, at p 0.05, than dermatitis, syncope, and forei gn body related injuries to the trunk region. General Cause of Injury The general cause of injury was examined for injuries of the trunk region. Information regarding the distributio n of injury by general cause of injury categories was provided for 11,201 worker injuries. Table 479 shows the trunk injury distribution for each of the general cause of injury classifications. Straining was the leadi ng cause of injuries to the trunk, comprising over64% (n = 7,190) of the injuries. Around 18% (n = 2,025) of the trunk in juries were caused by a fall or slip. Over 14% of the trunk injuries were caused by the combination of being struck by an object (n = 752), the absorption, ingestion, or inhalation of a substance (n = 505), and having struck against or stepped on an object (n = 331). Slightly more than one % (n = 124) of

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262 Figure 4126. Differences of injury severity means between nature of trunk injuries.

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263 the trunk injuries were caused by some kind of involvement with a motor vehicle. Having been Caught in or between an object or objects (n = 84), cut, punctured, or scraped (n = 84), burned (n = 64), and bitten or stung by animal or insect (n = 42) accounted for around three % of the trunk injuries. Table 479. General cause of trunk injury. General cause of injury Nature of Injury % Cumulative % Strain 7,190 64.19% 64.19% Fall or slip 2,025 18.08% 82.27% Struck by 752 6.71% 88.98% Absorption, ingestion, or inhalation 505 4.51% 93.49% Striking against or stepping on 331 2.96% 96.45% Motor vehicle 124 1.11% 97.55% Caught in or between 84 0.75% 98.30% Cut, puncture, or scrape 84 0.75% 99.05% Burn 64 0.57% 99.63% Animal or insect bite or sting 42 0.37% 100.00% Total 11,201 100.00% Injury severity means were compared among the ten general causes of injury for trunk injuries. Injury severity scores by general cause of injury were provided for 11,054 workers with trunk injuries. The results of the Levene test of homogeneity of injury severity score variances, for the ten general cause of injury groups, did no t allow for an assumption of equal variances, L (9, 11,044) = 25.63, p < 0.001. The results of the subsequent Welch test of equality of trunk injury severity means indicated that at least one general cause of injury group was significantly different of another group, F (9, 419.53) = 15.32, p < 0.001. This was confirmed by the results of the Tukeys b range test. Output of the Tukeys b test provided a ranking of the general cause of injury groups by their respective trunk injury seve rity means (see Figure 4127). Trunk injuries caused by being Caught in or between an object or objects had the highest injury severi ty mean ( = 1.50), followed by trunk injuries of a fall or slip ( = 1.50), involvement with some type of motor

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264 vehicle ( = 1.46), straining ( = 1.44), and bei ng struck by an object ( = 1.41). General causes of trunk injuries with the lowest injury severity means include having struck up against or stepped on an object ( = 1.40), absorption, ingestion, or inhala tion of a substance ( = 1.30), having been cut, punctured, or scraped ( = 1.16), and having been bitten or stung by an animal or insect ( = 1.10). The Tukeys test identifie d homogeneous subsets of trunk injury severity means that were not significantly different from each at p 0.05 (see Figure 4127). 1.10 (.30) 1.16 (.43) 1.30 (.58) 1.40 (.66) 1.41 (.64) 1.44 (.62) 1.46 (.61) 1.50 (.64) 1.50 (.82) 0.000.200.400.600.801.001.201.401.60 Animal or Insect Bite/Sting (n = 42) Injured by Cut, Puncture, or Scrape (n = 82) Absorption, Ingestion or Inhalation (n = 486) Striking Against or Stepping On (n = 326) Struck By (n = 734) Strain (n = 7115) Motor Vehicle (n = 120) Fall or Slip (n = 2005) Caught In or Between (n = 82) Injury Severity Mean (Standard Deviatioin) Figure 4127. Comparison of injury severity means by general cause of trunk injuries. From the arrangement of these homogeneous subs ets, specific differences of trunk injury severity means between the general causes of in jury were inferred, illustrated in Figure 4128. Among the trunk injuries, those caused by having been Caught in or between an object or objects had a significantly higher in jury severity mean, at p 0.05, than trunk injuries resulting from the absorption, ingestion, or inhalation of a substanc e, having been cut, punctured, or scraped by an object, and of a bite or sting of an animal or insect. Trunk inju ries caused by a slip or fall, involvement with a motor vehicle, straining, havi ng been struck by an object, and having struck

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265 against or stepped on an object had significan tly greater injury severity means, at p 0.05 than trunk injuries caused by being cut, punctured, or scraped by an object, and of animal bites or insect stings. 1.50 (.82) 1.50 (.64) 1.46 (.61) 1.44 (.62) 1.41 (.64) 1.40 (.66) 1.30 (.58) 1.16 (.43) 1.10 (.30) 0.000.200.400.600.801.001.201.401.60 Animal or Insect Bite/Sting (n = 42) Injured by Cut, Puncture, or Scrape (n = 82) Absorption, Ingestion or Inhalation (n = 486) Striking Against or Stepping On (n = 326) Struck By (n = 734) Strain (n = 7115) Motor Vehicle (n = 120) Fall or Slip (n = 2005) Caught In or Between (n = 82) Injury Severity Mean (Standard Deviatioin) Figure 4128. Differences of injury severi ty means by general causes of trunk injuries. Occupational Work Area Frequency information for the general occupational work area in which the worker was working at the time of the trunk injury was provided for 8,791 worker injuries. Trunk injury distribution for each of the work areas are shown inTable 480. Nearly 18% (n = 1,562) of the trunk injuries occurre d while the injured worker wa s working at some type of carpentry activity. Just over 15% (n = 1,368) of th e trunk injuries occurred while the worker was performing electrical work, followed by work involving iron and steel (n = 1,009, 11.48%), concrete (n = 551, 6.27%), technical repair or maintenance (n = 540, 6.14%), pipe fitting (n = 521, 5.93%), masonry (n = 393, 4.47%), equipment or machinery operations (n = 393, 4.47%), and plumbing (n = 325, 3.70%). Workers involved with sheet metal work at the time of the

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266 injury comprised around three % (n = 253) of the trunk injuries. The number of cases in each of the remaining 32 work areas, shown in Table 4combined to account for just under 20% of the injuries to the trunk. Trunk injury severity m eans were compared among the 42 general occupational work areas. Injury severity scores were provided fo r 8,701 workers with trunk injuries. The results of the Levene test of homogeneity of injury severity scor e variances for the 52 work areas did not allow for an assumption of equal variances, L (41, 8,659) = 4.65, p < 0.001. The results of the subsequent Welch test of equality of trunk injury severity means indicated that at least one work area was significantly different fr om another area, F (41, 256.20) = 2.50, p < 0.001. This was confirmed by the results of the Tukeys b range test. Output of the Tukeys b test provided a ranking of the general cause of injury groups by their respective trunk injury sever ity means (see Figure 4129). Work areas associated with the ten highest severity means for trunk injuries included flagging ( = 2.00, ), acoustic installation ( = 2.00), landscaping ( = 1.89, field engineeri ng ( = 1.67), flooring, til e or carpeting work ( = 1.62), technical repair or maintenan ce ( = 1.57), lathing ( = 1.56), HVAC and refrigeration ( = 1.53), painting or plastering ( = 1.53), and s ecurity ( = 1.53). Occupational work areas having the lowest five severity m eans for trunk injures included engineering ( = 1.25), insulation work ( = 1.25), waterproofing ( = 1.23), scaffold erection ( = 1.23), and rigging ( = 1.13). See Figure 4for the remaining occupational work areas with trunk injury severity m ean rankings. The Tukeys test id entified homogeneous subsets of trunk injury severity means that were not signi ficantly different from each at p 0.05 (see Figure 4129). Specific trunk injury severity mean differe nces were discerned from the homogeneous groupings displayed in Figure 4129. These are illustrated in Figure 4130. Trunk injuries

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267 Table 480. Occupational work ar ea workers with trunk injuries. Occupational work area Number of injuries % Cumulative % Carpentry 1,56217.77% 17.77% Electrical work 1,36815.56% 33.33% Iron/steel work 1,00911.48% 44.81% Concrete work 5516.27% 51.07% Technical repair and maintenance 5406.14% 57.22% Pipe fitting/laying 5215.93% 63.14% Masonry 3934.47% 67.61% Equipment /machinery operation 3934.47% 72.09% Plumbing 3253.70% 75.78% Sheet metal work 2532.88% 78.66% Boilermaker 2122.41% 81.07% Millwright work 1731.97% 83.04% Painting and plastering 1531.74% 84.78% Supervisory noc 1431.63% 86.41% Welding 1391.58% 87.99% Drywall work 1211.38% 89.36% Insulation 1161.32% 90.68% Driving 1121.27% 91.96% Lineman 800.91% 92.87% Roofing 670.76% 93.63% Glazing 650.74% 94.37% Clerical 570.65% 95.02% Managing 570.65% 95.67% Sprinkler fitting 500.57% 96.23% Steam fitting 470.53% 96.77% Inspecting 410.47% 97.24% Flooring, tile, or carpeting 370.42% 97.66% Engineering 290.33% 97.99% Scaffold erection 260.30% 98.28% Lathing 180.20% 98.49% Security 170.19% 98.68% Material handling 170.19% 98.87% Hod carrying 170.19% 99.07% HVAC/refrigeration 160.18% 99.25% Conveyor systems 150.17% 99.42% Waterproofing 140.16% 99.58% Landscaping 90.10% 99.68% Rigging 80.09% 99.77% Surveying 70.08% 99.85% Field engineering 60.07% 99.92% Acoustic ceiling work 40.05% 99.97% Flagging 30.03% 100.00% Total 8,791100.00%

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268 1.13 (.35) 1.23 (.51) 1.23 (.44) 1.25 (.49) 1.25 (.52) 1.29 (.49) 1.29 (.51) 1.35 (.49) 1.36 (.60) 1.37 (.53) 1.38 (.56) 1.40 (.63) 1.40 (.77) 1.41 (.60) 1.41 (.59) 1.42 (.62) 1.42 (.96) 1.43 (.61) 1.44 (.68) 1.45 (.66) 1.45 (.67) 1.45 (.73) 1.46 (.66) 1.47 (.71) 1.47 (.51) 1.48 (.64) 1.50 (.64) 1.50 (.55) 1.50 (.62) 1.51 (.63) 1.51 (.64) 1.52 (.59) 1.53 (.72) 1.53 (.61) 1.53 (.52) 1.56 (.51) 1.57 (.71) 1.62 (.54) 1.67 (.82) 1.89 (1.05) 2.00 (.82) 2.00 (1.00) 0.000.501.001.502.002.50 Rigging (n = 8) Scaffold Erection (n = 26) Waterproofing (n = 13) Insulation Work (n = 108) Engineering (n = 28) Clerical Work (n = 56) Supervision NOC (n = 142) Material Handling (n = 17) Plumbing (n = 321) Sprinkler Fitting (n = 49) Driving (n = 111) Conveyor Systems Work (n = 15) Steam Fitting (n = 47) Pipe Fitting (n = 519) Inspecting (n = 41) Millwright Work (n = 173) Managing (n = 57) Electrical Work (n = 1343) Lineman (n = 77) Sheet Metal Work (n = 251) Iron/Steel Work (n = 1001) Welding (n = 139) Concrete Work (n = 550) Glazing (n = 64) Hod Carrying (n = 17) Carpentry (n = 1553) Equipment or Machinery Operations (n = 383) Surveying (n = 6) Drywall Work (n = 119) Boilermaker (n = 212) Masonry (n = 391) Roofing (n = 67) Security (n = 17) Painting or Plastering (n = 151) HVAC/Refrigeration Work (n = 15) Lathing (n = 18) Technician (n = 537) Flooring, Tile, or Carpeting (n = 37) Field Engineering (n = 6) Landscaping (n = 9) Acoustic Ceiling Installation (n = 4) Flagging (n = 3) Injury Severity Mean (Standard Deviation) Figure 4129. Comparison of injury severity m ean by occupational work area for workers with trunk injuries.

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269 which occurred to workers while rigging show ed a significantly lower severity mean, at p 0.05, than those which occurred while workers were engaged in activities related to landscaping, Acoustic ceiling work, and flagging. In addition to rigging, workers involved with waterproofing or scaffold erection at the time of injury had si gnificantly lower trunk inju ry severity means, at p 0.05, than while flagging or inst alling acoustic ceiling systems. Figure 4130. Differences of injury severity m eans between occupational work area of workers with trunk injuries.

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270 Occupational Experience Level Trunk injuries were examined by workers o ccupational experience le vels at the time the injury occurred. Frequency information regarding the number of injured workers with trunk injuries and their respective e xperience levels was made available for 3,823 workers (see Table 481). Over 56% (n = 2,147) of the trunk injuri es were experienced by laborers. Foreman (n = 407) and journeyman (n = 377) level workers accounted for slightly over 20% of the trunk injuries. Apprentices experienced nearly 10% (n = 365) of the 3,823 trunk injuries. Helpers and assistants (n = 194), field superv isors (including superintendents and assistant superintendents) (n = 149), administrative personnel (n = 114), and professional level (n = 70) workers represented just under 9 % of the trunk injuries. Table 481. Occupational experience leve l of workers with trunk injuries. Occupational experience level Numb er of injuries % Cumulative % Laborer 2,147 56.16% 56.16% Foreman 407 10.65% 66.81% Journeyman 377 9.86% 76.67% Apprentice 365 9.55% 86.22% Helper/assistant 194 5.07% 91.29% Field supervisor 149 3.90% 95.19% Administrator 114 2.98% 98.17% Professional 70 1.83% 100.00% Total 3,823 100.00% The severity of trunk injuries relative to a workers expe rience level was examined by ranking and comparing experience levels by their respective injury severity means. Since an equal variance of trunk injury severity scores could not be assumed between the experience levels (L (7, 3,788) = 4.07, p < 0.001), the Welch test was conduc ted to assess equality of trunk injury severity means between experience levels. Th e results of this test indicated that at least one of the levels had a trunk injury severity mean that was signifi cantly different from one of the other levels, F (7, 526.27) = 2.64, p < 0.02. The results of the Tukey s b range test confirmed the

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271 Welch test result, and enabled the ranking of the eight occupational experien ce levels by their respective trunk injury severity means (see Figure 4131). Journeyman level workers displayed the highe st trunk injury severity mean ( = 1.50), followed by laborers ( = 1.45), apprentices ( = 1.43), foremen ( = 1.41), helpers and assistants ( = 1.41), administra tive level workers ( = 1.35), prof essionals ( = 1.35), and field supervisors ( = 1.30). The results of the Tuke ys b range test also identified homogeneous subsets of trunk injury severity means among the occupational experience levels. Experience levels within each subset did not have significa ntly different trunk injury severity means, at p 0.05, (see Figure 4131). 1.30 (.53) 1.35 (.56) 1.35 (.77) 1.41 (.61) 1.41 (.60) 1.43 (.61) 1.45 (.63) 1.50 (.63) 1.201.251.301.351.401.451.501.55 Field supervisor (n = 148) Professional (n = 69) Administrator (n = 113) Helper/Assistant (n = 193) Foreman (n = 405) Apprentice (n = 364) Laborer (n = 2131) Journeyman (n = 373) Injury Severity Mean (Standard Deviation) Figure 4134. Comparison of injury severity m eans by occupational experi ence level of workers with trunk injuries. Specific trunk injury severity mean differe nces were discerned from the homogeneous groupings displayed in see Figur e 4131. These are illustrated in Figure 4132. Trunk injuries which occurred to journeyman level workers gene rated a significantly high er severity mean, at p 0.05, than trunk injuries experienced by field supervisors.

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272 1.50 (.63) 1.45 (.63) 1.43 (.61) 1.41 (.60) 1.41 (.61) 1.35 (.77) 1.35 (.56) 1.30 (.53) 1.201.251.301.351.401.451.501.55 Field supervisor (n = 148) Professional (n = 69) Administrator (n = 113) Helper/Assistant (n = 193) Foreman (n = 405) Apprentice (n = 364) Laborer (n = 2131) Journeyman (n = 373) Injury Severity Mean (Standard Deviation) Figure 4132. Differences of injury severity means between occupational experience areas of workers with trunk injuries. Age The relationship between age and trunk injuries was explored from two perspectives. First, workers with trunk injuries were compared by th eir respective inclusion in one of seven age groups. With the exception of the under 20 and over 69 age groups, each of the age groups represented ten-year spans. Tr unk injuries were distributed be tween the age groups. This was followed by a comparison of trunk injuries severity means between the age groups. Second, a comparison of mean ages, between specific age groups was conducted. Frequency data for trunk injuries by the workers age group were provided for 3,789 workers (seeTable 482). Almost 31% (n = 1,16 1) of the trunk injuries were experienced by workers between 30 and 39 years of age. Around 26% (n = 977) of the trunk injuries were to workers 40 to 49 years old. Just under 24% (n = 9 05) of the trunk injuries occurred to workers between 50 and 59 years of age. Workers who were either 60 to 69 years old (n = 123) or under 20 years old (n = 55) combined to represent le ss than five % of the injuries to the trunk.

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273 Table 482. Age of worker s with trunk injuries. Age (years) Number of injuries % Cumulative % 30 39 years 1,161 30.64% 30.64% 40 49 years 977 25.79% 56.43% 20 29 years 905 23.88% 80.31% 50 59 years 568 14.99% 95.30% 60 69 years 123 3.25% 98.55% Under 20 years 55 1.45% 100.00% Total 3,789 100.00% Trunk injury severity means were compared among the six age groups. Injury severity scores were provided for 3,789 work ers with trunk injuries. The re sults of the Levene test of homogeneity of injury severity score variances for the six age groups did not allow for an assumption of equal variances, L (5, 3,731) = 27.49, p < 0.001. The results of the subsequent Welch test of equality of trunk injury severity means indicated that at least one age group was significantly different from another, F (5, 389.36) = 14.43, p < 0.001. This was confirmed by the results of the Tukeys b range test. The results of the Tukeys b test provided a ranking of the age groups by their respective trunk injury severity means (see Figure 4133). Workers 60 to 69 years of age had the highest severity mean ( = 1.71), followed by workers 50 to 59 ( = 1.48), 40 to 49 ( = 1.45), and 30 to 39 ( = 1.40, = 1.0.62) years old. Workers under the ag e of 20 ( = 1.37) and between 20 and 29 years old ( = 1.29) had the lowest trunk inju ry severity means among the age groups. The results from the Tukeys b ra nge test also identified homogeneous subsets of trunk injury severity means of among the age groups. Ag e groups within each subset did not have significantly different trunk in jury severity means, at p 0.05, (see Figure 4133). Specific trunk injury severity mean differences were discerned from the arrangement of the homogeneous subsets displayed in Figure 4133 These are illustrated in Figure 4134. The trunk injuries experienced by workers between the 60 and 69 old had a significantly higher

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274 injury severity mean, at p 0.05, than workers younger than 60 years old. Trunk injuries to workers between the ages of 50 and 59 years of ag e showed a significantly higher injury severity mean, at p 0.05, than trunk injuries experien ced by workers 20 to 29 years old. 1.29 (.52) 1.37 (.56) 1.40 (.62) 1.45 (.64) 1.48 (.69) 1.71 (.79) 0.000.200.400.600.801.001.201.401.601.80 20 29 Years (n = 899) Under 20 Years (n = 52) 30 39 Years (n = 1143) 40 49 Years (n = 963) 50 59 Years (n = 559) 60 69 Years (n = 121) Injury Severity Mean (Standard Deviation) Figure 4133. Comparison of injury severity means by age of workers with trunk injuries. 1.29 (.52) 1.37 (.56) 1.40 (.62) 1.45 (.64) 1.48 (.69) 1.71 (.79) 0.000.200.400.600.801.001.201.401.601.80 20 29 Years (n = 899) Under 20 Years (n = 52) 30 39 Years (n = 1143) 40 49 Years (n = 963) 50 59 Years (n = 559) 60 69 Years (n = 121) Injury Severity Mean (Standard Deviation) Figure 4134. Differences between injury se verity means by age group for trunk injuries. The mean ages of workers with trunk injuri es were compared by the specific body part impacted by the trunk injury. The results of the Levene test of homogeneity of age variances between the specific body parts of the trunk allowed for an assump tion of equal variances, L (12, 3,776) = 1.62, p > 0.05. Subsequently, the results of the ANOVA test indicated that at least one of body parts of the trunk region had a significantly different age mean from one of the other

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275 body parts, F (12, 3,776) = 4.11, p < 0.001. The results of the Tukeys b range test confirmed this test result, and enabled the ranking of the body parts by their re spective trunk injury severity means (see Figure 4135 and Figure 4136). Among trunk injuries, workers who experienced an impairment of the heart had the highest mean age ( = 47.44). Workers with lung injuri es ( = 41.60), multiple trunk injuries ( = 40.00), and injuries to the pelvis ( = 39.90) had the second, third, and fourth highest severity means, respectively. Workers with injuries to the lumbar or sacr al vertebrae ( = 38.31), lower back ( = 37.41), sacrum and coccyx ( = 36.27), and upper back ( = 36.27), had the lowest age means. For the rankings of the remaining trunk body parts by mean age, see Figure 4135. The Tukeys b test also identifi ed two homogeneous subsets, among the body parts of the trunk, for which mean ages in which body parts were not significantly different from each other at p 0.05. 36.27 (10.69) 36.27 (14.61) 37.41 (10.75) 38.31 (10.90) 38.80 (10.95) 38.90 (11.93) 39.11 (11.15) 39.38 (11.86) 39.89 (12.12) 39.90 (14.64) 40.00 (11.58) 41.60 (11.63) 47.44 (10.60) 05101520253035404550 Upper Back Area (n = 163) Sacrum & Coccyx (n = 11) Lower Back Area (n = 1694) Lumbar and/or Sacral Vertebrae (n = 209) Chest (n = 295) Abdomen (includes Groin) (n = 331) Shoulders (n = 735) Buttock (n = 21) Internal Organs NOC (n = 152) Pelvis (n = 10) Multiple Trunk Injuries (n = 14) Lungs (n = 138) Heart (n = 16) Mean Years of Age (Standard Deviation) Figure 4135. Comparison of mean ag es by injured body part of the trunk.

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276 From the two homogeneous groupings shown in Figure 4135, it was determined that workers who experienced heart injuries ha d a significantly higher mean age, at p 0.05, than workers who claimed an injury to the upper back (see Figure 4136). 47.44 (10.60) 41.60 (11.63) 40.00 (11.58) 39.90 (14.64) 39.89 (12.12) 39.38 (11.86) 39.11 (11.15) 38.90 (11.93) 38.80 (10.95) 38.31 (10.90) 37.41 (10.75) 36.27 (14.61) 36.27 (10.69) 05101520253035404550 Upper Back Area (n = 163) Sacrum & Coccyx (n = 11) Lower Back Area (n = 1694) Lumbar and/or Sacral Vertebrae (n = 209) Chest (n = 295) Abdomen (includes Groin) (n = 331) Shoulders (n = 735) Buttock (n = 21) Internal Organs NOC (n = 152) Pelvis (n = 10) Multiple Trunk Injuries (n = 14) Lungs (n = 138) Heart (n = 16) Mean Years of Age (Standard Deviation) Figure 4136. Differences of mean ages between inured body parts of the trunk. Job Tenure The number of days between the times an in jured worker was hire d and the time that injured worker experienced the trunk injury (i.e., job tenure) was examined. Information regarding the frequency of trunk injuries by the nine job tenure categories shown in Table 483 was provided for 9,122 worker injuries. Workers who had been employed from 91 to 180 days (n = 1,565) and those employed from 181 to 365 days (n = 1,529) accounted for nearly 17% each, of the trunk injuries. Nearly 25% of the trunk injuries were experi enced by workers in the first 60 days of employment (n = 2,247). Almost 11% of the trunk injuries were among workers employed from 366 to 730 days (n = 998). Workers injured between the 61st and 90th day of employment (n = 817) in addition to those injured between their 16th and 30th day of employment

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277 (n = 798) made up almost 18% of the trunk inju res. Trunk injury workers who were employed two or more years prior to being injured accounted for just fewer than 13% of the trunk injuries. Table 483. Job tenure of wo rkers with trunk injuries. Job tenure Number of injuries % Cumulative % 91 to 180 days 1,565 17.16% 17.16% 181 to 365 days 1,529 16.76% 33.92% 0 to 15 days 1,132 12.41% 46.33% 31 to 60 days 1,115 12.22% 58.55% 366 to 730 days (1 to 2 years) 998 10.94% 69.49% 61 to 90 days 817 8.96% 78.45% 16 to 30 days 798 8.75% 87.20% > 1461 days (> 4 years) 610 6.69% 93.88% 731 to 1460 days (2 to 4 years) 558 6.12% 100.00% Total 9,122 100.00% Job tenure categories were compared by their respective severity m eans for trunk injuries. The results of the Levene test of homogeneity of trunk injury severity score variances did not allow for the assumption of equal variances betw een the nine job tenure categories, L (8, 9,001) = 3.13, p < 0.003. Subsequently, the Welch test was perfor med to test the equality of trunk injury severity means between these categories. The results of this test indicated th at at least one of job tenure categories had a trunk injury severity mean that was significan tly different from one of the other categories, F (8, 3,246.21) = 2.29, p < 0.02. However, this result was not confirmed by the results the of the Tukeys b range test. The results of the Tukeys b range test are displayed in Figure 4137. The single homogeneous subset indicates that, at p 0.05, none of the job te nure categories had a significantly different trunk injury severity mean from any of th e other categories. Workers who were injured within the first fifteen days of employment, or between the 16th and 30th day, or between the first and second year of employment each had the same trunk injury severity mean of = 1.51. Workers with between 61 and 90 days em ployment had an injury severity mean of

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278 1.50, followed by workers with a job tenure of two or more years ( = 1.48). Workers who fell within the following job tenure gr oups had the lowest th ree trunk injury severity means, 31 to 60 days ( = 1.47), 91 to 180 days ( = 1.47), and 181 to 365 days ( = 1.43). 1.43 (.62) 1.47 (.66) 1.47 (.64) 1.48 (.62) 1.48 (.64) 1.50 (.64) 1.51 (.65) 1.51 (.65) 1.51 (.70) 1.381.401.421.441.461.481.501.52 181 to 365 Days (n = 1507) 31 to 60 Days (n = 1101) 91 to 180 Days (n = 1535) > 1461 Days (> 4 Years) (n = 602) 731 to 1460 Days (2 to 4 Years) (n = 554) 61 to 90 Days (n = 810) 0 to 15 Days (n = 1121) 16 to 30 Days (n = 790) 366 to 730 Days (1 to 2 Years) (n = 990) Injury Severity Mean (Standard Deviation) Figure 4137. Comparison of injury severity mean s by job tenure of workers with trunk injuries. Month of Occurrence of Injury The frequency of trunk injuries was examined by the month of the year during which the injury had occurred. Table 484 shows the numbe r of trunk injuries for each of the twelve months. Over 54% of the 11,646 trunk injuries oc curred within the months of October (n = 1,133), August (n = 1,070), May (n = 1,045), June (n = 1,038), September (n = 1,019), and July (n = 992). Trunk injuries occurring during the months of November (n = 865), December (n = 819), January (n = 865), February (n = 849), Marc h (n = 974), and April (n = 893) combined to account for around 46% of the injuries to the trunk region.

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279 Table 484. Month of occu rrence of trunk injuries. Month of occurrence of injury Nu mber of injuries % Cumulative % October 1,133 9.73% 9.73% August 1,070 9.19% 18.92% May 1,045 8.97% 27.89% June 1,038 8.91% 36.80% September 1,019 8.75% 45.55% July 992 8.52% 54.07% March 974 8.36% 62.43% January 949 8.15% 70.58% April 893 7.67% 78.25% November 865 7.43% 85.68% February 849 7.29% 92.97% December 819 7.03%100.00% Total 11,646 100.00% Injury severity for trunk injuries by the mont h of the injury was examined by ranking the months by their respective injury severity means and subsequen tly comparing the trunk injury severity means between the months to iden tify possible differences, significant at p 0.05. Severity scores, by month of the injury, were provided for 11,490 workers with injuries to the trunk. The results of an initial Levene test allo wed for an assumption of equal trunk injury score variances between the twelve months, L (11, 11,478) = 1.62, p > 0.08. The results of the subsequent ANOVA indicated that none of the months had a si gnificantly different trunk injury severity mean from any of the other months, F (11, 11,478) = 1.16, p > 0.30. This was confirmed by the results of the Tukeys b range test which did not identify any significant differences, at p 0.05, of trunk injury severity means between specific months. The rankings of the months of injury by tr unk injury severity means, generated by the Tukeys b test, are displayed in Figure 4138. Tr unk injuries occurring in January, October, and September had the highest severity mean of = 1.47. Trunk injuries in the December and June showed the lowest severity mean of = 1.41.

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280 1.41 (.61) 1.41 (.65) 1.42 (.61) 1.42 (.62) 1.44 (.64) 1.44 (.62) 1.44 (.65) 1.45 (.64) 1.46 (.65) 1.47 (.66) 1.47 (.64) 1.47 (.65) 1.381.391.401.411.421.431.441.451.461.471.48 June (n = 1028) December (n = 803) March (n = 957) July (n = 978) August (n = 1060) May (n = 1036) February (n = 836) November (n = 858) April (n = 866) September (n = 1012) October (n = 1124) January (n = 932) Injury Severity Mean (Standard Deviation) Figure 4138. Comparison of injury severity means by month of occurrence of trunk injuries. Day of the Week of Occurrence of Injury The possible relationship between trunk injuri es and the day of the week on which these injuries occurred was explored. Injury data for trunk injuries by each day of the week is displayed in Table 485. Nearly 20% of the trunk injuries o ccurred either on a Monday (n = 2,330) or a Tuesday (n = 2,236). Injuries occurri ng on Wednesdays (n = 2,153) and Thursdays (n = 2,130) each accounted for slightly over 18% of the trunk injuries. Around 16% (n = 1,900) of the trunk injuries occurred on a Friday. The remain ing seven % of the trunk injuries occurred on Saturdays (n = 616) and Sundays (n = 281). Injury severity for trunk injuries by the day of the week on which the injury occurred was examined by ranking the days of the week by their respective injury severity means and

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281 subsequently comparing the trunk injury severity means between the days to identify possible differences, significant at p 0.05. Severity scores, by day of the injury, were provided for 11,490 worker injuries to the trunk. The results of an initial Levene test did not allow for an assumption of equal trunk injury score variances between the seven days of the week, L (6, 11,483) = 1.62, p > 0.08. The results of the subsequent Welc h test indicated that none of the days of the week had a significantly different trunk inju ry severity mean from any of the other days, F (6, 2,454.65) = 1.34, p > 0.20. This was confirmed by the results of the Tukeys b range test which did not identify any significant differences, at p 0.05, of trunk injury severity mean differences between specific days. Table 485. Day of the week of occurrence of trunk injuries. Day of the week of occurrence Nu mber of injuries % Cumulative % Monday 2,330 20.01% 20.01% Tuesday 2,236 19.20% 39.21% Wednesday 2,153 18.49% 57.69% Thursday 2,130 18.29% 75.98% Friday 1,900 16.31% 92.30% Saturday 616 5.29% 97.59% Sunday 281 2.41% 100.00% Total 11,646 100.00% The rankings of the days of th e week of injury by trunk inju ry severity means, generated by the Tukeys b test, are displayed in Figure 4139. Trunk injuries occurring on Saturdays ( = 1.50) showed the highest injury severity mean among days on the week on which trunk injuries occurred. This was followed by trunk injuries ex perienced on Fridays ( = 1.46), Tuesdays ( = 1.45), Thursdays ( = 1.44), Sundays ( = 1.43) and Mondays ( = 1.43). Trunk injuries occurring on Wednesdays had the lowest severi ty mean, = 1.42, among the days of the week.

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282 1.42 (.63) 1.43 (.63) 1.43 (.66) 1.44 (.64) 1.45 (.64) 1.46 (.62) 1.50 (.71) 1.381.401.421.441.461.481.501.52 Wednesday (n = 2116) Monday (n = 2307) Sunday (n = 278) Thursday (n = 2105) Tuesday (n = 2195) Friday (n = 1877) Saturday (n = 612) Injury Severity Mean (Standard Deviation) Figure 4139. Comparison of injury severity m eans by day of the week of occurrence of trunk injuries. Upper Extremities Upper extremities and the severity of these injuries were examined by the specific body part injured (e.g., hand), the nature of the injury (e.g., laceration), the general cause of the injury (e.g., fall or slip), the occupational work area in which the injured worker was working at the time of the injury (e.g., carpentry) the workers occupational expe rience levels (e.g., apprentice), the job tenure of the injured worker prior to the in jury, the month of the year and day of the week on which the injury occurred, and the age of the injured worker at the time of the injury. A comparison of mean ages by specific body parts was also performed. Body Part Information regarding the specific injured body parts of the upper extremities was provided for 13,152 worker injuries. As Table 486 shows, in juries to fingers comprised almost 32% (n = 4,203) of the injuries to the upper extremities. In juries to the hands (n = 2,898), upper arm (n = 1,445), wrist (n = 1,401), wrist and hand (n = 122), and thumb (n = 1,318), combined to represent over 55% of the injuries to the upper extremities. Nearly 86% of upper extremities impacted body parts located below the elbow. Elbo w injuries (n = 968) combined with upper arm

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283 injuries (n = 535) to make up slightly over 11% of the injuries to the upper extremities. Multiple upper extremities injuries (n = 122) occurred just under one % of the time. Table 486. Injured body parts of the upper extremities. Body part Number of injuries % Cumulative % Finger 4,203 31.96% 31.96% Hand 2,898 22.03% 53.99% Lower arm 1,445 10.99% 64.98% Wrist 1,401 10.65% 75.63% Thumb 1,318 10.02% 85.65% Elbow 968 7.36% 93.01% Upper arm 535 4.07% 97.08% Multiple body patts 262 1.99% 99.07% Wrist and hand 122 0.93% 100.00% Total 13,152 100.00% Based on the severity scores provided fo r 12,939 workers with injuries to the upper extremities, the nine specific body part groups we re ranked by their respective injury severity means. Injury severity means were also compar ed between the nine body part groups. The results of the Levene test of homogeneity of injury se verity score variances between the nine body parts of the upper extremities did not allow for the as sumption of equal variances, L (8, 12,930) = 48.10, p < 0.001. Subsequently, the results of the Welch test of equality of injury severity means indicated that at least one of the body parts of the upper extremities had a significantly different injury severity mean than one of the other body parts, F (8, 1,588.97) = 20.62, p < 0.001. This was confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare body parts of the upper extremities by their respective injury severity means. From this test, each body part was ranked according to its respective injury severity mean (see Figure 4140). Multiple injuries had the highest severity mean ( = 1.55) among injuries to the upper extrem ities, followed by injuries to the wrist and the hand ( = 1.52). Injuries strictly of the wrist had the third highest injury severity mean ( =

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284 1.38), followed by injuries to the lower arm ( = 1.32), elbow ( = 1.27), finger ( = 1.24), hand ( = 1.23), and upper arm ( = 1.19). Injuries to th e thumb had the lowest injury severity mean, = 1.19, among injuries to the nine body parts of the upper extremities. Additionally, the results of the Tukeys b test identified four homogene ous subsets of body parts of the upper extremities in which there were no individual inju ry severity mean differences, at p 0.05, between subset body parts. 1.19 (.51) 1.22 (.50) 1.23 (.51) 1.24 (.54) 1.27 (.55) 1.32 (.57) 1.38 (.60) 1.52 (.70) 1.55 (.67) 0.000.200.400.600.801.001.201.401.601.80 Thumb (n = 1293) Lower Arm (n = 1412) Hand (n = 2860) Finger (n = 4141) Elbow (n = 950) Upper Arm (n = 527) Wrist (n = 1376) Wrist & Hand (n = 121) Multiple Injuries (n = 259) Injury Severity Mean (Standard Deviation) Figure 4140. Comparison of injury severi ty means by injured body parts of the upper extremities. Specific injury severity mean differences, significant at p 0.05, were discerned from the arrangement of the homogeneous subsets (see Fi gure 4141). Among the injuries to the upper extremities, injuries to the wrist, upper arm, elbow, finger, hand, upper arm and thumb, each had a significantly lower severity mean, at p 0.05, than multiple injuries to the upper extremities, and injuries to both the hand and the wrist si multaneously. Injuries to the wrist only were significantly more severe, at p 0.05, than elbow, finger, hand, lower arm, and thumb injuries.

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285 Upper arm injuries had a significantl y greater injury severity mean, p 0.05, than thumb injuries. 1.55 (.67) 1.52 (.70) 1.38 (.60) 1.32 (.57) 1.27 (.55) 1.24 (.54) 1.23 (.51) 1.22 (.50) 1.19 (.51) 0.000.200.400.600.801.001.201.401.601.80 Thumb (n = 1293) Lower Arm (n = 1412) Hand (n = 2860) Finger (n = 4141) Elbow (n = 950) Upper Arm (n = 527) Wrist (n = 1376) Wrist & Hand (n = 121) Multiple Injuries (n = 259) Injury Severity Mean (Standard Deviation) Figure 4141. Differences of injury seve rity means by injured body parts of the upper extremities. Nature of Injury Information regarding the upper extremities in juries by the nature of the injury was provided for 12,515 worker injuries. Almost 82% of the injuries to the upper extremities were attributed to the combination of lacerations (n = 4,805), contusions (n = 1,966), strains (n = 1,382), fractures (n = 1,101), and punctures (n = 1,002). As shown in Table 487, laceration (38.39%) was, recognizably, the most frequent nature of injury to the upper extremities. Contusions (n = 1,966), strains (n = 1,382), fr actures (n = 1,101), and punctures (n = 1,002) combined to account for 44% of the injuries to the upper extremities. Sprains (n = 557), crushing (n = 361), inflammations (n = 333), and burns (n = 324) together constituted almost 13% of the injuries to the upper extremities. See Table 487 for the relative upper extremity injury frequencies for the remaining 14 nature of injury categories.

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286 Table 487. Nature of injuries to the upper extremities. Nature of injury Number of injuries % Cumulative % Laceration 4,805 38.39% 38.39% Contusion 1,966 15.71% 54.10% Strain 1,382 11.04% 65.15% Fracture 1,101 8.80% 73.94% Puncture 1,002 8.01% 81.95% Sprain 557 4.45% 86.40% Crushing 361 2.88% 89.28% Inflammation 333 2.66% 91.95% Burn 324 2.59% 94.53% Carpal tunnel syndrome 93 0.74% 95.28% Infection 88 0.70% 95.98% Amputation 74 0.59% 96.57% Foreign body 74 0.59% 97.16% Multiple injuries 66 0.53% 97.69% Dermatitis 60 0.48% 98.17% Dislocation 49 0.39% 98.56% Severance 49 0.39% 98.95% Electric sShock 45 0.36% 99.31% Rupture 42 0.34% 99.65% Occupational disease NOC 23 0.18% 99.83% Poisoning NOC 14 0.11% 99.94% Freezing 5 0.04% 99.98% Total 12,515 100.00% Based on the severity scores provided for 12,312 worker injuries to the upper extremities, the 23 nature of injury categories were ranked by their respective injury severity means. Injury severity means were also compared by the nature of injury. The results of the Levene test of homogeneity of injury severity score variances between the 23 nature of upper extremity injury groups did not allow for the assumption of equal variances, L (22, 12,289) = 78.85, p < 0.001. Since enucleations of the upper extremities showed an injury score variance of zero, the Welch test of equality of severity means could not be performed. In lieu of the Welch test, the ANOVA test was conducted to examine injury severity mean differences between the nature of injury categories of upper extremity injuries. The result s of the ANOVA indicated that at least one of the nature of upper extremity injury groups had a significantly different injury severity mean

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287 than one of the other groups, F (22, 12,289) = 451.53, p < 0.001. This was confirmed by the results of the Tukeys b range test. The Tukeys b range test was performed to compare nature of upper extremity injury classifications by their respective injury severity means. From this test each of the nature of injury categories were ranked according to their respective upper extremity injury severity mean (see Figure 4142). Among the na ture of injury of upper ex tremity injury categories, amputations resulted in the highest injury severity mean of 2.10. Along with amputations, ruptures ( = 1.88) severances ( = 1.87), carpal tunnel syndro me ( = 1.70), occupational disease, not otherwise classified ( = 1.67), fr acture ( = 1.60), freezing ( = 1.53), dislocation ( = 1.52), multiple injury ( = 1.43), and pois oning ( = 1.39) had the ten highest severity means among the nature upper extremity injury groups. Contusion ( = 1.14), foreign body ( = 1.10), puncture ( = 1.05), and dermatitis ( = 1. 00), were associated with the nature of upper extremity injury categories with the lowest five injury severity means. The remaining nature of upper extremity injury groups with severity m eans are shown in Figure 4142. Additionally, the results of the Tukeys b test id entified six homogeneous subsets of nature of upper extremity injury categories in which ther e were no individual injury se verity means differences, at p 0.05, between subset members. Specific injury severity mean differences, significant at p 0.05, were discerned from the arrangement of the homogeneous subsets (see Fi gure 4-143)). Among the injuries to the upper extremities, amputations had a significantly greater injury severity mean, at p 0.05, than all of the remaining nature of injury groups except ruptures, severan ces, and carpal tunnel syndrome. Ruptures had a significantly higher injury sever ity mean than all of th e remaining groups of

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288 1.00 (0.00) 1.05 (.23) 1.10 (.33) 1.14 (.35) 1.17 (.46) 1.17 (.46) 1.20 (.48) 1.22 (.47) 1.23 (.54) 1.24 (.43) 1.27 (.53) 1.35 (.59) 1.39 (.63) 1.43 (.51) 1.52 (.68) 1.53 (.79) 1.60 (.89) 1.67 (.70) 1.70 (.56) 1.87 (.70) 1.88 (.76) 2.10 (.69) 0.000.501.001.502.002.50 Dermatitis (n = 57) Puncture (n = 986) Foreign Body (n = 73) Contusion (n = 1922) Laceration (n = 4717) Burn (n = 316) Electric Shock (n = 45) Inflammation (n = 329) Infection (n = 88) Sprain (n = 546) Strain (n = 1363) Crushing (n = 357) Poisoning NOC (n = 14) Multiple Injuries (n = 66) Dislocation (n = 49) Freezing (n = 5) Fracture (n = 1095) Occupational Disease NOC (n = 23) Carpal Tunnel Syndrome (n = 95) Severance (n = 48) Rupture (n = 42) Amputation (n = 74) Injury Severity Mean (Standard Deviation) Figure 4142. Comparison of injury severity mean s by nature of injury to the upper extremities.

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289 Figure 4143. Difference of injury severity means by nature of injury to the upper extremities.

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290 nature of injury means except severances, carp al tunnel syndrome, occ upational diseases NOC, and fractures. Occupational diseases NOC and fractures had significantly higher severity means, at p 0.05, than strains, sprains, infections inflammations, electric shocks, burns, lacerations, contusions, foreign bodies, punctures, and dermatitis. Severances and carpal tunnel syndrome had a significantly highe r injury severity mean, at p 0.05, than that for foreign bodies, punctures, and dermatitis. Dermatitis had a significantly lower injury severity mean, at p 0.05, than freezing injuries of the upper extremities. The results of the Tukeys b test identified six homogeneous subsets of nature of upper extr emity injury categories in which there was no individual injury severi ty mean difference, at p 0.05, between subset categories General Cause of Injury From information provided for 12,849 worker injuries, the upper extremity injury distribution for general cause of injury categories were genera ted and ranked in descending magnitudes (see Table 488). Almost 34% of the injuries to the upper extremities were caused by cuts, punctures or scrapes (n = 4,331). Having been struck by an object (n = 1,863), Caught in or between an object or objects (n = 1,860), or having suffered a strain (n = 1,791) accounted for around 14% each, of the upper extremity injuries. A fa ll or slip (n = 1,312) was cited as the cause of injury for 10% of the upper extremity injury cases. Workers who were injured by striking up against or stepping on an object (n = 975), being burned (n = 326), bitten or stung by an animal or insect (n = 223), absorbing, ingesting, or inha ling a substance (n = 137), and engaging with a motor vehicle (n = 31), combined to make up ove r 13% of the remaining upper extremity injury cases. Injury severity scores, by the general cause of the injury to the upper extremity, were provided for 12,641 worker injuries. Based on this information, injury severity means were

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291 generated for and compared between the ten general cause of injury categorie s. The results of the Levene test of homogeneity of injury severity score variances between th e ten cause of injury Table 488. General cause of injury to the upper extremities. General cause of injury Number of injuries % Cumulative % Cut, puncture, or scrape 4,331 33.71% 33.71% Struck by 1,863 14.50% 48.21% Caught in or between 1,860 14.48% 62.68% Strain 1,791 13.94% 76.62% Fall or slip 1,312 10.21% 86.83% Strike against or step on 975 7.59% 94.42% Burn 326 2.54% 96.96% Animal or insected bite or sting 223 1.74% 98.69% Absorption, ingestion or inhalation 137 1.07% 99.76% Motor vehicle 31 0.24% 100.00% Total 12,849 100.00% categories did not allow for the assumpti on of equal variances, L (9, 12,631) = 137.81, p < 0.001. The results of the subsequent We lch test indicated that at leas t one of the cause of injury categories had a significantly different injury severity mean than one of the other categories, F (9, 635.70) = 48.95, p < 0.001. This was confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare the cause of upper extremity injury categories by their respective injury severity means. From this test, each cause of injury categories was ranked according to its respective upper extremity injury severity mean (see Figure 4144). Among the causes of upper extrem ity injury categories, falls or slips are associated with upper extremity injuries with the highest injury severity mean, = 1.47, followed by involvement with a motor vehicle ( = 1.43) and strains ( = 1.37). Injuries caused by being Caught in or between an object or object s yielded the fourth highest injury severity mean, = 1.29. This was followed by upper extrem ity injuries caused by being struck by an object ( = 1.25), having struck against or stepped on an object ( = 1.24), being burned ( = 1.21), being cut, punctured, or scraped ( = 1.16), and having absorbed, ingested, or inhaled a

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292 substance ( = 1.14). Upper extremity injuries caused by an animal or insect bite or sting had the lowest injury severity mean of the general cause of injury categories. Th e results of the Tukeys b test identified five homogeneous subsets of general cause of upper extremity injury categories in which there was no individual inju ry severity mean difference, at p 0.05, between subset members (see Figure 4144). 1.11 (.54) 1.14 (.49) 1.16 (.44) 1.21 (.48) 1.24 (.54) 1.25 (.52) 1.29 (.60) 1.37 (.59) 1.43 (.63) 1.47 (.66) 0.000.200.400.600.801.001.201.401.60 Animal or Insect Bite/Sting (n = 220) Absorption, Ingestion or Inhalation (n = 134) Cut, Puncture, or Scrape (n = 4256) Burn (n = 318) Striking Against or Stepping On (n = 957) Struck By (n = 1828) Caught In or Between (n = 1839) Strain (n = 1766) Motor Vehicle (n = 30) Fall or Slip (n = 1293) Injury Severity Mean (Standard Deviation) Figure 4144. Comparison of injury severity m eans by general cause of upper extremity injury. Specific injury severity mean differences, significant at p 0.05, were discerned from the arrangement of the homogeneous subsets (see Figure 4145). Among the general causes of upper extremity injuries, those of a fall or slip resulted in upper extremities injuries with a severity mean significantly greater, at p 0.05, than those associated with the remaining general causes, except involvement with a motor vehicle, and strains. Upper extremities injuries caused by involvement with some type of motor vehicle had a significantly high er severity mean, at p 0.05, than having been struck by, struck against or stepped on, Caught in or between an object or objects, burned, cut, punctured, or scraped, having absorbed, ingested, or inhaled a substance, and having been bitten or stung by an animal or insect. Injuries to the upper extremities brought

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293 about by a strain had a significan tly greater severity mean, at p 0.05, than those caused by being burned, cut, punctured, or scraped, absorption, ingestion, or inhalation of a substance, and an animal or insect bite or sting. Having b een Caught in or between an object or objects generated upper extremities injuries with a signifi cantly higher severity mean than those due to an animal or insect bite or sting. 1.47 (.66) 1.43 (.63) 1.37 (.59) 1.29 (.60) 1.25 (.52) 1.24 (.54) 1.21 (.48) 1.16 (.44) 1.14 (.49) 1.11 (.54) 0.000.200.400.600.801.001.201.401.60 Animal or Insect Bite/Sting (n = 220) Absorption, Ingestion or Inhalation (n = 134) Cut, Puncture, or Scrape (n = 4256) Burn (n = 318) Striking Against or Stepping On (n = 957) Struck By (n = 1828) Caught In or Between (n = 1839) Strain (n = 1766) Motor Vehicle (n = 30) Fall or Slip (n = 1293) Injury Severity Mean (Standard Deviation) Figure 4145. Differences of injury severity m eans by the general causes of injury to the upper extremities. Occupational Work Area The general occupational work area categories identified the specific work area in which the injured worker was involved at the time of the injury. Of the 9,983 upper extremities injury cases, for which occupational work area information was available, over 51% were experienced by workers while working in the of carpentry (n = 2,282), electrical wo rk (n = 1,690), and iron and steel work (n = 1,127). Table 489 shows the upper extremities injury frequencies for 42 occupational work areas. As this table illustrates, work areas associated with least number of injuries to the upper extremities included waterproof ing (n = 18), rigging (n = 16), security (n =

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294 16), surveying (n = 13), material handling (n = 12 ), field engineering (n = 12), acoustic ceiling work (n = 5), hod carrying (n = 5), landscaping (n = 2), and flagging (n = 2). These ten work areas accounted for less than 1 % of the upper extremities injuries. Injury severity scores, by the occupationa l work area associated with upper extremity injury, were provided for 9,874 work er injuries. Based on this information, injury severity means were generated for and compared between the 42 occupational work areas. The results of the Levene test of homogeneity of injury severity score variances between th e 42 work areas did not allow for the assumption of equal variances, L (41, 9,832) =7.25, p < 0.001. The Welch test of equality of means could not be performed because professional engineering, flagging, and landscaping had zero variances (see Figure 4). In lieu of th e Welch test, the ANOVA was conducted and the results suggested that at least one of the work areas could have an injury severity mean for upper injuries that was significantly different than one of the other work areas, F (41, 9,832) = 2.18, p < 0.001. This was not confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare the occupational work areas by their respective upper extremities injury severity mean s. From this test, each work area was ranked according to its respective upper extremity injury severity mean (see Figure 4146). Among the workers work areas for upper extremity injuries, rigging was associated with upper extremity injuries with the highest injury severity mean, = 1.44, followed by surveying ( = 1.42), painting or plastering ( = 1.40), hod carrying ( = 1.40), driving ( = 1.40), millwright work ( = 1.38), and roofing ( = 1.36). Occupational work areas associated with the ten lowest upper extremities injury severity means were, flooring, tile, or carpeting ( = 1.20), acoustic ceiling work ( = 1.20), sheet metal work ( = 1.20), managing ( = 1.16), clerical work ( = 1.10), conveyor systems work ( = 1.09), field engineering ( = 1.08), professional engineering

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295 Table 489. Injury frequency by occupational work area of workers with upper extremityinjuries Occupational work area Number of injuries% Cumulative % Carpentry 2,282 22.86% 22.86% Electrical Work 1,690 16.93% 39.79% Iron/Steel Work 1,127 11.29% 51.08% Technical repair or maintenance 598 5.99% 57.07% Concrete work 527 5.28% 62.35% Pipe Fitting 463 4.64% 66.98% Sheet Metal Work 433 4.34% 71.32% Plumbing 376 3.77% 75.09% Masonry 356 3.57% 78.65% Equipment or machinery Operation 267 2.67% 81.33% Boilermaker 225 2.25% 83.58% Millwright 210 2.10% 85.69% Supervision 153 1.53% 87.22% Drywall 151 1.51% 88.73% Painting and plastering 126 1.26% 89.99% Welding 120 1.20% 91.20% Roofing 84 0.84% 92.04% Glazing 75 0.75% 92.79% Insulation 74 0.74% 93.53% Driving 70 0.70% 94.23% Clerical 70 0.70% 94.93% Lineman 64 0.64% 95.57% Flooring. tile, or carpeting 55 0.55% 96.12% Steam fitting 52 0.52% 96.64% Sprinkler fitting 41 0.41% 97.05% Managing 38 0.38% 97.44% Lathing 33 0.33% 97.77% Inspecting 30 0.30% 98.07% Scaffold erection 29 0.29% 98.36% Conveyor systems work 23 0.23% 98.59% HVAC/refrigeration 20 0.20% 98.79% Engineering 20 0.20% 98.99% Waterproofing 18 0.18% 99.17% Rigging 16 0.16% 99.33% Security 16 0.16% 99.49% Surveying 13 0.13% 99.62% Material handling 12 0.12% 99.74% Field engineering 12 0.12% 99.86% Acoustic ceiling work 5 0.05% 99.91% Hod carrying 5 0.05% 99.96% Landscaping 2 0.02% 99.98% Flagging 2 0.02% 100.00% Total 9,983 100.00%

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296 1.00 (.00) 1.00 (.00) 1.00 (.00) 1.08 (.29) 1.09 (.29) 1.10 (.35) 1.16 (.37) 1.20 (.46) 1.20 (.45) 1.20 (.45) 1.21 (.48) 1.21 (.47) 1.21 (.46) 1.21 (.50) 1.22 (.51) 1.24 (.56) 1.25 (.52) 1.25 (.44) 1.25 (.62) 1.25 (.53) 1.26 (.51) 1.27 (.59) 1.27 (.57) 1.27 (.54) 1.28 (.60) 1.29 (.56) 1.30 (.56) 1.30 (.53) 1.31 (.58) 1.31 (.59) 1.32 (.60) 1.32 (.59) 1.33 (.48) 1.33 (.49) 1.34 (.70) 1.36 (.55) 1.38 (.66) 1.40 (.71) 1.40 (.55) 1.40 (.55) 1.42 (.67) 1.44 (.63) 0.000.200.400.600.801.001.201.401.60 Landscaping (n = 2) Flagging (n = 2) Professional Engineering (n = 20) Field Engineering (n = 12) Conveyor Systems Work (n = 23) Clerical Work (n = 69) Managing (n = 37) 13 Sheet Metal Workers (n = 427) Acoustic Ceiling Work (n= 5) Flooring, Tile or Carpeting Work (n = 54) Supervisory Work (n = 150) Welding (n = 119) Steam Fitting (n = 52) Electrical Work (n = 1658) Plumbing (n = 369) Lathing (n = 33) Glazing (n = 72) HVAC/Refrigeration (n = 20) Material Handling (n = 12) Pipe Fitting (n = 460) Drywall Work (n = 149) Security (n = 15) Iron/Steel Work (n = 1115) Carpentry (n = 2272) Sprinkler Fitting (n = 40) Concrete Work (n = 526) Masonry (n = 354) Inspecting (n = 30) Equipment or Machinery Operation (n = 262) Boilermaker (n = 223) Insulation (n = 72) Technical Repair or Maintenance (n = 593) Scaffold Erection (n = 27) Waterproofing (n = 18) Lineman (n = 64) Roofing (n = 81) Millwright Work (n = 208) Driving (n = 70) Hod Carrying (n = 5) Painting or Plastering (n = 126) Surveying (n = 12) Rigging (n = 16) Injury Severity Mean (Standard Deviation) Figure 4146. Comparison of injury severity m eans by occupational work area of workers with upper extremity injuries.

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297 ( = 1.00), flagging ( = 1.00), and landscaping ( = 1.00). See Figure 4for the rankings of the occupational work areas. The results of the Tukeys b test identified a single hom ogeneous subset of occupational work in which there was no individual injury severity mean difference, at p 0.05, between subset memb ers (see Figure 4146). Occupational Experience Level Upper extremities injury information regardi ng the workers occupational experience was provided for 4,180 worker injuries. As Table 490 shows, laborers had over 53% (n = 2.239) of the injuries to the upper extrem ities. Apprentices (n = 560), journeymen (n = 426), and foremen (n = 416), experienced over 33% of the total in juries to the upper extremities. Helpers and assistants comprised around five % (n = 216) of the workers with uppe r extremities injuries. Supervisors (n = 165), administrato rs (n = 108), and professionals (n = 50) represented less than 8 % each, of the individuals with injuries to the upper extremities. Table 490. Occupational experience level of wo rkers with injuries to the upper extremities. Occupational experience level Numb er of injuries % Cumulative % Laborer 2,239 53.56% 53.56% Apprentice 560 13.40% 66.96% Journeyman 426 10.19% 77.15% Foreman 416 9.95% 87.11% Helper/assistant 216 5.17% 92.27% Field supervisor 165 3.95% 96.22% Administrative 108 2.58% 98.80% Professional 50 1.20% 100.00% Total 4,180 100.00% Injury severity means were compared among th e eight occupational experience levels for injuries to the upper extremities. Injury severity scores by experience level were provided for 4,139 workers with trunk injuries. The results of the Levene test of homogeneity of injury severity score variances for the eight experience levels did not allow for an assumption of equal variances, L (7, 4,131) = 8.38, p < 0.001. The results of the subsequent Welch test of equality of

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298 upper extremities injury severity means indicated th at at least one general cause of injury group was significantly different fr om another group, F (7, 483.36) = 3.38, p < 0.005. This was confirmed by the results of the Tukeys b range test. Output of the Tukeys b test provided a ranking of the general cause of injury groups by their respective upper extremities in jury severity means (see Figure 4147). Upper extremities injuries to journeymen had the highest injury severity mean ( = 1.30), followed by injuries to laborers ( = 1.27), foremen ( = 1.26), apprentices ( = 1.25), helpers and assistants ( = 1.22), field supervisors ( = 1.20), and professionals ( = 1.18). Administrativ e level workers with injuries to the upper extremities showed the lowe st injury severity mean, = 1.12. The Tukeys test identified two homogeneous subsets of inju ry severity means for injuries to the upper extremities for the occupational experience levels. Experience levels within each subset did not have upper extremities injury severity means that were significantly different from each other at p 0.05 (see Figure 4147). 1.12 (.36) 1.18 (.44) 1.20 (.47) 1.22 (.53) 1.25 (.52) 1.26 (.55) 1.27 (.54) 1.30 (.56) 1.001.051.101.151.201.251.301.35 Administrative (n = 106) Professional (n = 50) Field Supervisor (n = 162) Helper/Assistant (n = 213) Apprentice (n = 555) Foreman (n = 412) Laborer (n = 2215) Journeyman (n = 426) Injury Severity Mean (Standard Deviation) Figure 4147. Comparison of injury severity m eans by occupational experi ence level of workers with upper extremity injuries. From the arrangements of the homogeneous groups shown in Figure 4148, specific and significant at p 0.05, differences of severity means for injuries to the upper extremities were

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299 identified between eight occupational experience levels (see Figure 4). Journeymen with injuries to th e upper extremities showed a significantly greater, at p 0.05, severity mean than administrative personnel with injuries to the upper extremities. 1.30 (.56) 1.27 (.54) 1.26 (.55) 1.25 (.52) 1.22 (.53) 1.20 (.47) 1.18 (.44) 1.12 (.36) 1.001.051.101.151.201.251.301.35 Administrative (n = 106) Professional (n = 50) Field Supervisor (n = 162) Helper/Assistant (n = 213) Apprentice (n = 555) Foreman (n = 412) Laborer (n = 2215) Journeyman (n = 426) Injury Severity Mean (Standard Deviation) Figure 4148. Differences of injury severity m ean by occupational experience levels for workers with upper extremity injuries. Age The relationship between age and injuries to the upper extremities was explored in two ways. First, workers with upper extremities injuries were compared by their respective ages. With the exception of the under 20 and over 69 groups, each of the age groups represented tenyear spans. Injury frequencies were compared between the age groups. This was followed by a comparison of upper extremities injury se verity means between the age groups. Information for injuries to the upper extremities by the workers age was provided for 4,333 worker injuries (see Table 491). Almost 29% (n = 1,239) of th e injuries to the upper extremities were experienced by workers betw een 30 and 39 years of age. Around 28% (n = 1,206) of the injuries were to workers 20 to 29 years old. Nearly 25% (n = 1,114) of upper extremity injuries occurred to workers who were between 40 and 49 years of age, followed by

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300 workers aged 50 to 59 (n = 558, 12.88%). Workers aged under 20 years old (n = 109) and aged 60 to 69 years (n = 107) experienced almost 5 % to tal, of the injuries to the upper extremities. Table 491. Age of workers with upper extremity injuries. Age (years) Number of injuries % Cumulative % 30 to 39 1,239 28.59% 28.59% 20 to 29 1,206 27.83% 56.43% 40 to 49 1,114 25.71% 82.14% 50 to 59 558 12.88% 95.02% Under 20 109 2.52% 97.53% 60 to 69 107 2.47% 100.00% Total 4,333 100.00% Injury severity means for upper extremity injuries were compared among the six age groups. Injury severity scores were provided fo r 4,266 worker injuries to the upper extremities. The results of the Levene test of homogeneity of injury severity score variances for the six age groups did not allow for an assumption of equal variances, L (5, 4,260) = 20.60, p < 0.001. The results of the subsequent Welch test of equa lity of upper extremities injury severity means indicated that at leas t one age group was significantly diffe rent from another group, F (5, 564.01) = 6.16, p < 0.001. This was confirmed by the results of the Tukeys b range test. The results of the Tukeys b test provided a ranking of the age groups by their respective upper extremities injury severity means (see Figu re 4149). Workers 60 to 69 years of age had the highest severity mean ( = 1.33), followed by workers 40 to 49 ( = 1.30), 50 to 59 ( = 1.29), and 30 to 39 ( = 1.25) years old. Worker s under the age 20 ( = 1.17) and between 20 and 29 years old ( = 1.20) had the two lowest in jury severity means fo r injuries to the upper extremities among the age groups. The results of the Tukeys b range test identified two homogeneous subsets of severity means for upper extremities injuries among the age groups. Age groups within each subset did not have signi ficantly different injury severity means, at p 0.05, from each other (see Figure 4149). Figur e 4149 shows a trend of increasing injury

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301 severity of upper extremity injuries as workers get older. The Kendalls tau b correlation test was conducted to examine this relations hip. The results of a Kendalls tau test for correlation between injury severity and age of the worker w ith an upper extremity inju ry indicated a slight, though significant, at p 0.01, correlation of 0.70. 1.17 (.42) 1.20 (.47) 1.25 (.53) 1.29 (.58) 1.30 (.58) 1.33 (.60) 1.051.101.151.201.251.301.35 Under 20 (n = 106) 20 29 (n = 1191) 30 39 (n = 1219) 50 59 (n = 552) 40 -49 (n = 1091) 60 69 (n = 107) Injury Severity Mean (Standard Deviation) Figure 4149. Comparison of injury severity means by age of workers with upper extremity injuries. Specific upper extremities injury severity mean differences were discerned from the arrangement of the homogeneous subsets displa yed in Figure 4149. These are illustrated in Figure 4150. Workers between 60 and 69 years of age showed a signif icantly higher injury severity mean, at p 0.05, than trunk injuries experienced by workers less than 20 years of age. 1.33 (.60) 1.30 (.58) 1.29 (.58) 1.25 (.53) 1.20 (.47) 1.17 (.42) 1.051.101.151.201.251.301.35 Under 20 (n = 106) 20 29 (n = 1191) 30 39 (n = 1219) 50 59 (n = 552) 40 -49 (n = 1091) 60 69 (n = 107) Injury Severity Mean (Standard Deviation) Figure 4150. Differences of injury severity mean s by ages of workers with injuries to the upper extremities.

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302 The mean ages of workers with injuries to the upper extremities were compared by the specific body part impacted by the injury. The resu lts of the Levene test of homogeneity of age variances between the specific body parts of the upper extremities allowed for an assumption of equal variances, L (8, 4,324) = 0.38, p > 0.90. Subsequently, the results of the ANOVA test indicated that at least one of body parts of the upper extremities was associated with a significantly different mean age of one from the other body parts, F (8, 4,324) = 6.60, p < 0.001. The results of the Tukeys b ra nge test confirmed this test result and enabled the ranking the body parts by their respective injury severity means (see Figure 4151). Among injuries of to the upper extremities, workers who experienced multiple injuries to the upper extremities had the highest mean age, = 43.13 years. This was followed by injuries to the wrist and hand ( = 39.88), elbow ( = 38.97), upper arms ( = 38.38), wrist only ( = 37.95), lower arm ( = 37.12), finger ( = 36.71), and hand ( = 36.11). Workers with injuries to the thumb showed the lowest mean age, = 35.51. As illustrated in Figure 4151, the Tukeys b test identified three homogeneous subsets of body parts of the upper extremities, in which mean ages were not significantly different at p 0.05. 35.51 (11.60) 36.11 (11.11) 36.71 (11.19) 37.12 (10.80) 37.95 (11.14) 38.38 (10.92) 38.97 (10.95) 39.88 (11.08) 43.16 (11.55) 05101520253035404550 Thumb (n = 434) Hand (n = 916) Finger (n = 1439) Lower Arm (n = 447) Wrist (n = 513) Upper Arm (n = 169) Elbow (n = 304) Wrist & Hand (n = 48) Multiple Upper Extremity Injuries (n = 63) Mean Age (Standard Deviation) Figure 4151. Comparison of mean ages by upper extremity body part injured.

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303 From the arrangement of the three homogene ous subsets, it was discerned that workers with multiple injuries to the upper extremities had a significantly greater mean age, at p 0.05, than workers experiencing injuries to any of the other body parts of the upper extremities (see Figure 4152). In addition, workers with injuries to both the hand and the wrist had a significantly greater mean age, at p 0.05, than workers with injuries to thumb and injuries to the hand only. 43.16 (11.55) 39.88 (11.08) 38.97 (10.95) 38.38 (10.92) 37.95 (11.14) 37.12 (10.80) 36.71 (11.19) 36.11 (11.11) 35.51 (11.60) 05101520253035404550 Thumb (n = 434) Hand (n = 916) Finger (n = 1439) Lower Arm (n = 447) Wrist (n = 513) Upper Arm (n = 169) Elbow (n = 304) Wrist & Hand (n = 48) Multiple Upper Extremity Injuries (n = 63) Mean Age (Standard Deviation) Figure 4152. Differences of mean ag es by injured upper extremity body part. Job Tenure The number of days between the time an injure d worker was hired and the time that worker sustained an injury to the upper extremities (i.e., job tenure) was explored. Information regarding the frequency of injuries to the upper extremities by the nine j ob tenure groups, shown in Table 492, was provided for 9,833 worker injuries. Workers who had been employed of 91 to 180 days (n = 1,647) and those employed of 181 to 365 days (n = 1,626) accounted for nearly 17% each, of the injuries to the upper extremities. N early 13% of the upper extremities injuries were experienced by workers in the first 15 days of employment (n = 1,301) and 13% by those with 31 to 60 days (n = 1,234) of employment. Almost 11% of the injuries to the upper extremities were

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304 among workers employed of 366 to 730 days (n = 1,027). Workers injured between the 61st and 90th day of employment (n = 845) in addi tion to those injured between their 16th and 30th day of employment (n = 857) made up almost 17% of the upper extremity in juries. Workers with injuries to the upper extremities who were employe d two or more years prior to being injured accounted for just over 13% of the upper extremities injuries. Table 492. Job tenure for workers with injuries to the upper extremities. Job tenure Number of injuries % Cumulative % 91 to 180 days 1,647 16.75% 16.75% 181 to 365 days 1,626 16.54% 33.29% 0 to 15 days 1,301 13.23% 46.52% 31 to 60 days 1,234 12.55% 59.07% 366 to 730 days (1 to 2 years) 1,027 10.44% 69.51% 16 to 30 days 857 8.72% 78.23% 61 to 90 days 845 8.59% 86.82% 731 to 1460 days (2 to 4 years) 681 6.93% 93.75% > 1461 days (> 4 years) 615 6.25% 100.00% Total 9,833 100.00% Job tenure categories were compared by their respective severity means for injuries to upper extremities. The results of the Levene test of homogeneity of trunk injury severity score variances did not allow for the assumption of equal variances between the nine job tenure categories, L (8, 9,683) = 6.78, p < 0.001. Subsequently, the Welch test was performed to test the equality of the upper extremities injury severity means between these categories. The results of this test indicated that at leas t one of the job tenure categories ha d an injury severity mean that was significantly different from one of the other categories, F (8, 3,501.05) = 2.23, p < 0.03. This result was not confirmed by the results the of the Tukeys b range te st (see Figure 4153). Figure 4153 displays the results of the Tukeys b range test. The single homogeneous subset indicates that, at p 0.05, none of the job tenure categor ies had a significantly different trunk injury severity mean from any of the other categories. Workers who were injured within

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305 the first fifteen days of employment ( = 1.33) along with those employed for more than four years ( = 1.33), had the highest severity means for injuries to the upper extremities. These were followed by workers who had been employed betw een two and four years ( = 1.31), between 61 and 90 days ( = 1.30), 16 and 30 days ( = 1.30), of one to two years ( = 1.28), and 31 to 60 days ( = 1.28). The lowest two upper extremities injury severity means were associated with workers employed 91 to 180 days ( = 1.27) and 181 to 365 days ( = 1.26). The single homogeneous subset of job sever ity means (see Figure 4153) by job tenure categories indicates that, at p 0.05, none of the job categories had a se verity mean for injuries to the upper extremities significantly different of any of the other job tenure categories. 1.26 (.54) 1.27 (.55) 1.28 (.55) 1.28 (.58) 1.30 (.54) 1.30 (.55) 1.31 (.59) 1.33 (.60) 1.33 (.60) 1.221.241.261.281.301.321.34 181 to 365 Days (n = 1596) 91 to 180 Days (n = 1620) 31 to 60 Days (n =1221) 366 to 730 Days (1 to 2 Years) (n = 1018) 16 to 30 Days (n = 846) 61 to 90 Days (n = 829) 731 to 1460 Days (2 to 4 Years) (n = 672) > 1461 Days (Greater than 4 Years) (n = 612) 0 to 15 Days (n = 1278) Injury Severity Mean (Standard Deviation) Figure 4153. Comparison of injury severity means by job tenure of workers with upper extremity injuries. Month of Occurrence of Injury Based on information provided for 13,147 cases t he frequency of upper extremity injuries was examined by the month of the year during wh ich the injury had occurred. Table 493 shows the distribution of injuries to the upper extremities by month. Almost 40% of the injuries occurred within the months of July (n = 1,333), August (n = 1,315), October (n = 1,258), and September (n = 1,206). Around eight % of the inju ries to the upper extremities occurred during

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306 each of the months of June (n = 1,151), April (n = 1,106), May (n = 1,077), March (n = 1,039), and November (n = 1,024). The remaining 20% of the injuries to the upper extremities occurred during winter months of January (n = 898), December (n = 8 87), and February (n = 853). Table 493. Month of occurren ce of upper extremity injuries. Month of injury occurrence Numb er of injuries % Cumulative % July 1,333 10.14% 10.14% August 1,315 10.00% 20.14% October 1,258 9.57% 29.71% September 1,206 9.17% 38.88% June 1,151 8.75% 47.64% April 1,106 8.41% 56.05% May 1,077 8.19% 64.24% March 1,039 7.90% 72.15% November 1,024 7.79% 79.93% January 898 6.83% 86.77% December 887 6.75% 93.51% February 853 6.49% 100.00% Total 13,147 100.00% Injury severity for injuries to the upper extremities by the month of the injury was examined by ranking the months by their respective injury seve rity means and subsequently comparing the injury severity means between the months to identify possible differences, significant at p 0.05. Severity scores, by month of the injury, were provided for 12,934 worker injuries to the upper extremities. The results of an initial Levene test did not allow for an assumption of equal injury severity score vari ances between the twelve months, L (11, 12,922) = 3.62 p < 0.001. The results of the subsequent Welch test indicated that none of the months had a significantly different upper extremities injury severity mean from any of the other months, F (11, 4,953.67) = 1.32, p > 0.20. This was confirmed by the resu lts of the Tukeys b range test which did not identify any significant differences, at p 0.05, of injury severity mean between specific months.

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307 The rankings of the month of injury occurrence by upper extrem ity injury severity means, generated by the Tukeys b test, are displayed in Figure 4. Injuries to the upper extremities which occurred in April ( = 1.29) and March ( = 1.29) had the highest severity m eans. The months of January and May each had the second hi ghest severity mean for injuries to the upper extremities, = 1.28. These were followed by the months of December, November, and October, each recording an upper extremities injury severity mean of = 1.26. Injuries occurring during the month of February ( = 1.25) had the fifth lo west severity mean, pr eceded by the months of September, August, June and July, each with a se verity mean for injuries to the upper extremities equal to 1.24. The results of the Tukeys b test identified a single homogene ous group of severity means over twelve months. (see Figure 4154). This in dicates that no significan tly different severity means, at p 0.05, could be detected between specific months when injuries to the upper extremities occurred. 1.24 (.53) 1.24 (.55) 1.24 (.54) 1.24 (.54) 1.25 (.52) 1.26 (.53) 1.26 (.52) 1.26 (.56) 1.28 (.52) 1.28 (.56) 1.29 (.54) 1.29 (.56) 1.221.231.241.251.261.271.281.291.30 July (n = 1321) June (n = 1139) August (n = 1296) September (n = 1183) February (n = 833) October (n = 1246) November (n = 1015) December (n = 866) May (n = 1064) January (n = 873) March (n = 1011) April (n = 1087) Injury Severity Mean (Standard Deviation) Figure 4154. Comparison of injury severity m eans by month of occurrence of injuries to the upper extremities.

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308 Day of the Week of Occurrence of Injury The possible relationship between injuries to the upper extremities and the day of the week on which these injuries occurred was explored. Injury data for uppe r extremity injuries by day of the week is displayed in Table 494. Nearly 20% of the upper extr emity injuries occurred either on a Wednesday (n = 2,528), Thursday (n = 2,525), or Tuesday (n = 2,503). Injuries occurring on Monday (n = 2,467) accounted for nearly 19% of the injuries to the upper extremities. Around 17% of the trunk injuries occurr ed on a Friday (n = 2,290). Near ly four % of upper extremity injuries occurred on Saturdays (n = 625) and over one % on Sundays (n = 209). Injury severity for injuries to the upper extremities by the day of the week on which the injury occurred was examined by ranking the days of the week by their respective injury severity means and subsequently comparing the upper extrem ity injury severity means between the days to identify possible differences, significant at p 0.05. Severity scores, by day of the injury, were provided for 11,490 worker injuries to the upper extremities. The results of an initial Levene test did not allow for an assumption of equal upper extremity injury score variances between the seven days of the week, L (6, 12,927) = 3.39, p < 0.003. The results of the subsequent Welch test indicated that none of the days of the w eek had a significantly different injury severity mean from any of the other days of the week, F (6, 2,125.18) = 1.19, p > 0.30. This was confirmed by the results of the Tuke ys b range test, which did not identify any significant differences, at p 0.05, of upper extremity injury severity means between specific days of the week. The rankings of the days of the week by upper extremity injury severi ty means, generated by the Tukeys b test, are displayed in Figure 4155. Injuries to the upper extremities occurring on Sundays ( = 1.31) showed the highest inju ry severity mean among days on the week on which trunk injuries occurred. This was followed by injuries experienced on Fridays ( = 1.28),

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309 Mondays ( = 1.27), Wednesdays ( = 1.26), Satu rdays ( = 1.26), and Tuesdays ( = 1.25). Injuries occurring on Thursdays had the lowest severity mean, = 1.24, among the days of the week. Table 494. Day of the week of o ccurrence of upper extremity injuries. Day of the week of njury Numb er of injuries % Cumulative % Wednesday 2,528 19.23% 19.23% Thursday 2,525 19.21% 38.43% Tuesday 2,503 19.04% 57.47% Monday 2,467 18.76% 76.24% Friday 2,290 17.42% 93.66% Saturday 625 4.75% 98.41% Sunday 209 1.59% 100.00% Total 13,147 100.00% A single homogeneous group of severity means including Monday through Sunday was identified by the Tukeys b test (see Figure 4155 ). This indicates that no significantly different severity means, at p 0.05, could be detected between specific days of the week on which the injuries to the upper extremities occurred. 1.24 (.52) 1.25 (.53) 1.26 (.55) 1.26 (.57) 1.27 (.54) 1.28 (.55) 1.31 (.54) 1.201.221.241.261.281.301.32Thursday (n = 2483) Tuesday (n = 2466) Saturday (n = 623) Wednesday (n = 2487) Monday (n = 2416) Friday (n = 2252) Sunday (n = 207)Injury Severity Mean (Standard Deviation) Figure 4155. Comparison of injury severity m eans by day of the week of occurrence of upper extremity injuries Lower Extremities Injuries to the lower extremities and the severity of these injuries were examined by the specific body part injured (e.g., knee) the nature of the injury (e .g., laceration), the general cause

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310 of the injury (e.g., fall or slip ), the occupational work area in which the injured worker was working at the time of the injury (e.g., carpent ry), the workers occupational experience level (e.g., apprentice), the job tenure of the injured worker pr ior to the injury, the month of the year and day of the week on which the injury occurred, and th e age of the injured worker at the time of the reported injury. A comparison of mean ages by specific body parts injured was also performed. Body Part Frequency information regarding the specifi c injured body parts of the lower extremities was provided for 9,193 worker injuries. Table 495 illustrates, injuries to the knee comprised almost 34% (n = 3,106) of the injuries to the lower extremities. Ankle (n = 1,867) and foot (n = 1,847) injuries each accounted for just over 20% of the lower extremity injuries. Nearly 13% of the lower extremity injuries were to the lower leg (n = 1,167). Fe wer injuries were sustained by the upper leg (n = 440), the toe (n = 307), hip (n = 220), great toe (n = 123), and multiple body parts of the lower ex tremities (n = 116). Table 495. Injured body parts of the lower extremities. Body part Number of injuries % Cumulative % Knee 3,106 33.79% 33.79% Ankle 1,867 20.31% 54.10% Foot 1,847 20.09% 74.19% Lower leg 1,167 12.69% 86.88% Upper leg 440 4.79% 91.67% Toe 307 3.34% 95.01% Hip 220 2.39% 97.40% Great toe 123 1.34% 98.74% Multiple injuries 116 1.26% 100.00% Total 9,193 100.00% Based on the severity scores provided for 9,080 worker injuries to the lower extremities, the nine specific body part groups were ranked by their respective in jury severity means. Injury severity means were also compared between the nine body part groups. The results of the Levene

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311 test of homogeneity of injury severity score va riances between the nine body parts of the lower extremities did not allow for the assumption of equal variances, L (8, 9,071) =53.22, p < 0.001. Subsequent the results of the Welc h test of equality of injury severity means indicated that at least one of the body parts of the lower extremities had a significantly different injury severity mean than one of the other body parts, F (8, 963.13) = 25.17, p < 0.001. This was confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare body parts of the lower extremities by their respective injury severity means. From this test, each of the body parts was ranked according to its respective injury severity mean (see Figure 4156). Multiple injuries had the highest severity mean ( = 1.58) among injuries to the lower extremities, followed closely by injuries to the knee ( = 1.51). Inju ries to the hip had the third highe st injury severity mean ( = 1.44), followed by injuries to the ankle ( = 1.39), lower leg ( = 1.36), toe ( = 1.36), upper leg ( = 1.33), great toe ( = 1.31), and foot ( = 1.2 7). Additionally, the results of the Tukeys b test identified four homogene ous subsets of lower extremities body parts in which there was no individual injury severi ty mean difference, at p 0.05, between subset members. 1.27 (.53) 1.31 (.53) 1.33 (.59) 1.36 (.56) 1.36 (.60) 1.39 (.61) 1.44 (.57) 1.51 (.67) 1.58 (.71) 0.000.200.400.600.801.001.201.401.601.80 Foot (n = 1820) Great Toe (n = 120) Upper Leg (n = 431) Toe (n = 301) Lower Leg (n = 1152) Ankle (n = 1848) Hip (n = 218) Knee (n = 3074) Multiple Body Parts (n = 116) Injury Severity Mean (Standard Deviation) Figure 4156. Comparison of injury severi ty means by injured body parts of the lower extremities.

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312 Specific injury severity mean differences, significant at p 0.05, were discerned from the arrangement of the homogeneous subsets (see Fi gure 4157). Among the injuries to the lower extremities, injuries to multiple body parts of th e lower extremities had a significantly greater injury severity mean, at p 0.05, than all of the other body arts, except the knee. Knee injuries had a significantly greater injury severity mean, p 0.05, than injuries to the lower leg, toe, upper leg, great toe, and foot. Hip injuries had a significantly highe r severity mean, at p 0.05, than foot injuries. 1.58 (.71) 1.51 (.67) 1.44 (.57) 1.39 (.61) 1.36 (.60) 1.36 (.56) 1.33 (.59) 1.31 (.53) 1.27 (.53) 0.000.200.400.600.801.001.201.401.601.80 Foot (n = 1820) Great Toe (n = 120) Upper Leg (n = 431) Toe (n = 301) Lower Leg (n = 1152) Ankle (n = 1848) Hip (n = 218) Knee (n = 3074) Multiple Body Parts (n = 116) Injury Severity Mean (Standard Deviation) Figure 4157. Differences of injury severity means between injured body parts of the lower extremities. Nature of Injury Information regarding the injury frequency of lower extremities injuries by the nature of the injury was provided for 8,620 worker injuries (see Table 496). Around 26% of the injuries to the upper extremities were strain injuries (n = 2,228). Contusions (n = 1,952) accounted for almost 23%, while sprains accounted for nearly 17% (n = 1,430), and punctures accounted for 10% (n = 862) of the reported injuries to the lower extremities. Fractures (n = 802) and lacerations (n = 561) combined to represent almost 16% of the inju ries. The nature of injury for

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313 the remaining 9 % of the upper extremity injuries was distributed among the 16 remaining classifications shown in Table 496. Table 496. Nature of injury to the lower extremities. Nature of injury Number of injuries % Cumulative % Strain 2,228 25.85% 25.85% Contusion 1,952 22.65% 48.49% Sprain 1,430 16.59% 65.08% Puncture 862 10.00% 75.08% Fracture 802 9.30% 84.39% Laceration 561 6.51% 90.89% Inflammation 217 2.52% 93.41% Rupture 159 1.84% 95.26% Burn 134 1.55% 96.81% Crushing 73 0.85% 97.66% Infection 51 0.59% 98.25% Dislocation 45 0.52% 98.77% Multiple injuries 42 0.49% 99.26% Dermatitis 14 0.16% 99.42% Foreign body 12 0.14% 99.56% Amputation 10 0.12% 99.68% Poisoning NOC 9 0.10% 99.78% Severance 6 0.07% 99.85% Occupational disease NOC 6 0.07% 99.92% Electric shock 3 0.03% 99.95% Freezing 3 0.03% 99.99% Chemical poisoning 1 0.01% 100.00% Total 8,620 100.00% Based on the severity scores provided fo r 8,515 workers with injuries to the lower extremities, 21 nature of injury categories were ranked by their respective injury severity means. The single chemical poisoning case had an injury severity score of one. Since the Tukeys b range test could not be performed when one of the groups has a sample size less than two the single chemical poisoning case wa s excluded from the comparative analysis of severity means between the nature of injury cat egories. Injury severity means were also compared between the remaining 21 nature of injury groups. The results of the Levene test of homogeneity of injury severity score variances between the 21 nature of lower extremity injury groups did not allow for

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314 the assumption of equal variances, L (20, 8,494) = 50.90, p < 0.001. However, due to the fact that electric shocks and occ upational disease not otherwise cl assified (NOC) of the lower extremities had injury score variances of zero, the We lch test of equality of severity means could not be performed. In lieu of the Welch test, th e ANOVA test was conducted to explore injury severity mean differences between the nature of lower extremity injury gr oups. The results of the ANOVA indicated that at least one of the nature of lower extremity injury groups had a significantly different injury severity mean than one of the other groups, F (20, 8,494) = 82.50, p < 0.001. This was confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare nature of lower extremity injury classifications by their respective injury severity means. From this test, each nature of injury category was ranked according to its respective lowe r extremity injury severity mean (see Figure 4158). Among the nature of injury of lower extremity injury categ ories, amputations resulted in the highest injury severity mean, = 2.50. Al ong with amputations, ruptures ( = 2.37), dislocations ( = 2.31), occupational disease NO C ( = 2.00), multiple in juries to the lower extremities ( = 1.86), fractures ( = 1.85), severa nces ( = 1.83), poisoning ( = 1.67), crushing ( = 1.65), and foreign body ( = 1.50) comprised the top ten injury severity means by nature of injury to the lower extremities. The remaining el even nature of lower extremity injury groups with severity means are shown in Figure 4158. Additionally, the results of the Tukeys b test identified five homogeneous subsets of nature of lower extremity injury categories in which there was no individual injury severity mean difference, at p 0.05, between subset members. Specific injury severity mean differences, significant at p 0.05, were discerned from the arrangement of the homogeneous subsets (see Fi gure 4159). Among the injuries to the lower extremities, amputations and ruptures had significantly greater injury severity means, at p 0.05,

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315 than all of the remaining nature of injury groups except, disl ocations, occupational diseases NOC, multiple injuries, fractures, an d severances. Dislocations had a significantly higher injury severity mean than the same group as amputa tions and ruptures, except poisoning NOC, and crushing. Occupational diseases NOC had a signif icantly greater injury severity mean, at p 0.05, than lacerations, contusions, dermatitis, pun ctures, and electric shocks. Electric shock injuries of the lower extremities also showed a significantly lower severity mean, at p 0.05, than multiple injuries to the lower extremitie s, fractures, and severances among the lower extremities. 1.00 (.00) 1.13 (.38) 1.21 (.43) 1.23 (.50) 1.23 (.48) 1.31 (.57) 1.33 (.58) 1.37 (.59) 1.37 (.56) 1.43 (.61) 1.45 (.63) 1.50 (.52) 1.65 (.70) 1.67 (.50) 1.83 (.75) 1.85 (.66) 1.86 (.81) 2.00 (.00) 2.31 (.73) 2.37 (.59) 2.50 (.85) 0.000.501.001.502.002.503.00 Electric Shock (n = 3) Puncture (n = 853) Dermatitis (n = 14) Contusion (n = 1910) Laceration (n = 552) Inflammation (n = 215) Freezing (n = 3) Sprain (n = 1412) Burn (n = 134) Infection (n = 49) Strain (n = 2209) Foreign Body (n = 12) Crushing (n = 72) Poisoning NOC (n = 9) Severance (n = 6) Fracture (n = 800) Multiple Injuries (n = 42) Occupational Disease NOC (n = 6) Dislocation (n = 45) Rupture (n = 159) Amputation (n = 10) Injury Severity Mean (Standard Deviation) Figure 4158. Comparison of injury severity means by nature of lower extremity injuries.

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316 Figure 4159. Differences of injury severity mean s by nature of injury to the lower extremities. General Cause of Injury From information provided for 8,995 worker injuries, the lower extremity injury distribution by general cause of injury categories was generated and ranked in descending order of frequency (see Table 497). Over 30% of the injuries to the lower extremities were caused by a slip or fall (n = 2,709). Strains were attributed as the cause of injury for over 27% (n = 2,444)

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317 of the injuries to the lower extremities. Around 17% of the workers with lower extremity injuries had sustained struck by injuries (n = 1,538). Ten % of the lower extremity injuries were caused by the workers striking against or stepping on an object (n = 900). N early nine % were caused by a cut, puncture or scrape (n = 778). The remaini ng seven % of injuries to the lower extremities are displayed in Table 497. Table 497. General cause of lower extremity injuries. General cause of injury Number of injuries % Cumulative % Fall or slip 2,709 30.12% 30.12% Strain 2,444 27.17% 57.29% Struck by 1,538 17.10% 74.39% Strike against or st epping on 900 10.01% 84.39% Cut, puncture, or scrape 778 8.65% 93.04% Caught in or between 308 3.42% 96.46% Burn 121 1.35% 97.81% Animal or insect bite or sting 107 1.19% 99.00% Absorption, ingestion, or inhalation 53 0.59% 99.59% Motor vehicle 37 0.41% 100.00% Total 8,995 100.00% Injury severity scores, by the general cause of the injury to the lower extremities, were provided for 8,883 worker injuries. Based on this information, injury severity means were generated for and compared between the ten general cause of injury categorie s. The results of the Levene test of homogeneity of injury severity score variances between the general cause of injury groups did not allow for the assumption of equal variances, L (9, 8,873) = 95.30, p < 0.001. The results of the subsequent Welch test indicated that at l east one of the cause of injury categories had a significantly different injury severity mean than one of the other categories, F (9, 471.74) = 42.20, p < 0.001. This was confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare general cause of lower extremity injury classifications by their resp ective injury severity means. From this test, each of the cause of injury categories was ranked ac cording to their respective lo wer extremity injury severity

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318 mean (see Figure 4160). Among the causes of lo wer extremity injuries, involvement with a motor vehicle was associated with the highest in jury severity mean, = 1.57. This was followed by lower extremity injuries caused by having been Caught in or between an object or objects ( = 1.53), falling or slipping ( = 1.49), strain s ( = 1.44), and being burned ( = 1.36). Having been struck by an object was associated with lo wer extremity injuries with the fifth highest severity mean, = 1.35. This was followed by lowe r extremity injuries caused by the absorption, ingestion, or inhalation of a substance ( = 1.25) having struck against or having stepped on an object ( = 1.25), and being cut, punctured, or scraped ( = 1.17). Lower extremity injuries caused by an animal or insect bite or sting ha d the lowest injury seve rity mean, = 1.14. The results of the Tukeys b test identified thr ee homogeneous subsets of general cause of lower extremity injury categories in which there was no i ndividual injury severity mean difference, at p 0.05, between subset memb ers (see Figure 4160). Specific injury severity mean differences, significant at p 0.05, were discerned from the arrangement of the homogeneous subsets (see Figure 4161). Among the general causes of lower extremity injuries, those involving a motor vehicle, having been Caught in or between an object or objects, and of falling or slipping, each had significantly higher injury severity means, at p 0.05, than the severity means associated wi th lower extremity in juries caused by the absorption, ingestion, or inhalation of a substance, having struck agai nst, or stepped on an object, been cut, punctured, or scraped, and a bite from an animal or insect sting. In addition, lower extremity injuries of straining had a significantly greater severity mean, at p 0.05, than injuries of cuts, punctures, or scrapes, and injuries of animal b ites and stings of insects.

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319 1.57 (.69) 1.53 (.74) 1.49 (.66) 1.44 (.63) 1.36 (.56) 1.35 (.60) 1.25 (.48) 1.25 (.51) 1.17 (.44) 1.14 (.40) 0.000.200.400.600.801.001.201.401.601.80 Animal or Insect Bite or Sting (105) Cut, Punture, or Scrape (n = 769) Striking Against or Stepping On (n = 889) Abosrption, Ingestion, or Inhalation (n = 52) Struck By (n = 1511) Burn (n = 121) Strain (n = 2416) Fall or Slip (n = 2678) Caught In or Between (n = 305) Motor Vehicle (n = 37) Injury Severity Mean (Standard Deviation) Figure 4160. Comparison of injury severity mean s by general cause of lower extremity injuries. 1.57 (.69) 1.53 (.74) 1.49 (.66) 1.44 (.63) 1.36 (.56) 1.35 (.60) 1.25 (.48) 1.25 (.51) 1.17 (.44) 1.14 (.40) 0.000.200.400.600.801.001.201.401.601.80 Animal or Insect Bite or Sting (105) Cut, Punture, or Scrape (n = 769) Striking Against or Stepping On (n = 889) Abosrption, Ingestion, or Inhalation (n = 52) Struck By (n = 1511) Burn (n = 121) Strain (n = 2416) Fall or Slip (n = 2678) Caught In or Between (n = 305) Motor Vehicle (n = 37) Injury Severity Mean (Standard Deviation) Figure 4161. Difference of injury severity means by general causes of lo wer extremity injuries. Occupational Work Area The general occupational work area categories identified the specific work area in which the injured worker was involved at the time of the injury. Of the 6,941 lower extremities injury cases, 46% were experienced by workers while wo rking in areas, such as carpentry (n = 1,293),

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320 electrical work (n = 1,072), and iron and stee l work (n = 828). Table 498 shows the lower extremities injury frequencies for all 42 of the general occupational work areas. As this table illustrates, work areas associated with least num ber of injuries to the lower extremities included waterproofing (n = 11), material handling (n = 10), lathing (n = 9), acoustic ceiling work (n = 8), surveying (n = 8), field engineering (n = 8), HVA C/refrigeration work (n = 6), hod carrying (n = 6), landscaping (n = 3), and flagging (n = 3). Th ese ten work areas accounted for around 1 % of the injuries to the lower extremities. Injury severity scores, by the occupational wo rk area associated w ith the injury to the lower extremity, were provided for 6,871 worker injuries. Based on this information, injury severity means were generated for and compar ed between the 42 occupational work areas. The results of the Levene test of homogeneity of injury severity score variances between the 42 occupational areas did not allow for the a ssumption of equal variances, L (41, 6,829) = 4.27, p < 0.001. The Welch test of equality of means could not be performed because hod carrying and acoustic ceiling work each had zer o variances (see Figure 4162). In lieu of the Welch test, the ANOVA was conducted and the results suggested that at least one of the work areas could have had an injury severity mean for lower extremity in juries that was significantly different than one of the other work areas, F (41, 6,829) = 1.75, p < 0.003. However, this was not confirmed by the results of Tukeys b range test. The Tukeys b range test was performed to compare the occupational work areas by their respective lower extremities injury severity means. This test ranked each work area according to its lower extremity injury severity mean (see Figure 4162). Among the 42 work areas, workers involved in conveyor systems work showed the highest severity mean ( = 1.79) for injuries to the lower injuries.Flagging ( = 1.67), material handling ( = 1.60), floori ng, tile, and carpentry

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321 Table 498. Occupational work areas of workers with lower extremity injuries. Occupational work area Number of injuries% Cumulative % Carpentry 1,293 18.63% 18.63% Electrical 1,072 15.44% 34.07% Iron/steel 828 11.93% 46.00% Concrete 469 6.76% 52.76% Technical repair or maintenance 448 6.45% 59.21% Pipe fitting 383 5.52% 64.73% Equipment or machinery operation 296 4.26% 69.00% Plumbing 250 3.60% 72.60% Masonry 238 3.43% 76.03% Sheet metal 204 2.94% 78.97% Boilermaker 156 2.25% 81.21% Supervision NOC 155 2.23% 83.45% Millwright 134 1.93% 85.38% Painting or plastering 110 1.58% 86.96% Welding 97 1.40% 88.36% Drywall 79 1.14% 89.50% Driving 74 1.07% 90.56% Clerical 65 0.94% 91.50% Glazing 60 0.86% 92.36% Lineman 55 0.79% 93.16% Roofing 54 0.78% 93.93% Insulating 50 0.72% 94.65% Steam fitting 49 0.71% 95.36% Engineering 42 0.61% 95.97% Managing 40 0.58% 96.54% Sprinkler fitting 31 0.45% 96.99% Flooring. tile, or carpeting 30 0.43% 97.42% Inspecting 28 0.40% 97.82% Scaffold erection 23 0.33% 98.16% Security 23 0.33% 98.49% Rigging 19 0.27% 98.76% Convey systems work 14 0.20% 98.96% Waterproofing 11 0.16% 99.12% Material handling 10 0.14% 99.27% Lathing 9 0.13% 99.39% Acoustic ceiling work 8 0.12% 99.51% Surveying 8 0.12% 99.63% Field engineering 8 0.12% 99.74% HVAC/refrigeration 6 0.09% 99.83% Hod carrying 6 0.09% 99.91% Landscaping 3 0.04% 99.96% Flagging 3 0.04% 100.00% Total 6,941 100.00%

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322 1.00 (.00) 1.00 (.00) 1.13 (.35) 1.13 (.35) 1.17 (.41) 1.17 (.46) 1.22 (.44) 1.23 (.56) 1.25 (.54) 1.30 (.56) 1.33 (.58) 1.33 (.57) 1.36 (.62) 1.36 (.60) 1.37 (.67) 1.37 (.63) 1.38 (.60) 1.38 (.58) 1.38 (.59) 1.38 (.61) 1.39 (.50) 1.39 (.59) 1.39 (.54) 1.40 (.60) 1.40 (.52) 1.41 (.64) 1.41 (.65) 1.42 (.60) 1.42 (.66) 1.42 (.66) 1.43 (.61) 1.43 (.63) 1.44 (.60) 1.45 (.55) 1.47 (.74) 1.53 (.61) 1.55 (.66) 1.56 (.66) 1.60 (.62) 1.60 (.70) 1.67 (.58) 1.79 (.70) 0.000.200.400.600.801.001.201.401.601.802.00 Acoustic Ceiling Work (n = 8) Hod Carrying (n = 6) Surveying (n = 8) Field Engineering (n = 8) HVAC/Refrigeration Work (n = 6) Clerical Work (n = 64) Lathing (n = 9) Sprinkler Fitting (n = 31) Managing (n = 40) Scaffold Erection (n = 23) Landscaping (n = 3) Professional Engineering (n = 42) Inspecting (n = 28) Insulation (n = 50) Steam Fitting (n = 49) Supervision NOC (n = 151) Electrical Work (n = 1053) Plumbing (n = 248) Welding (n = 97) Boilermaker (n = 156) Security (n = 23) Masonry (n = 237) Drywall Work (n = 76) Millwright Work (n = 134) Waterproofing (n = 10) Equipment or Machinery Operations (n = 293) Pipe Fitting (n = 379) Roofing (n = 53) Iron and Steel Work (n = 819) Concrete Work (n = 468) Sheet Metal Work (n = 197) Carpentry (n = 1282) Glazing (n = 59) Painting and Plastering (n = 110) Driving (n = 74) Rigging (n = 19) Technical Repair and Maintenance (n = 447) Lineman Work (n = 54) Flooring, Tile, Carpeting (n = 30) Material Handling (n = 10) Flagging (n = 3) Conveyor Systems Work (n = 14) Injury Severity Mean (Standard Deviation) Figure 4162. Comparison of injury severity m eans by occupational work areas of workers with lower extremity injuries.

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323 work ( = 1.60), lineman work ( = 1.56), and t echnical repair and ma intenance ( = 1.55) represented the work areas with the top five lower extremity injury severity means. Work areas associated with the lowest seven severity means for injuries to the lower extremities included sprinkler fitting ( = 1.23), lathing ( = 1.22), clerical work ( = 1.17), HVAC/refrigeration work ( = 1.17), field engineering ( = 1.13), surveying ( = 1.13), hod carrying ( = 1.00), and acoustic ceiling work ( = 1.00). The single homogeneous subset of injury seve rity means shown in Figure 4162 indicated that none of the work areas had an upper injury severity mean that significantly different, at p 0.05, of any of the other work areas. Occupational Experience Level Lower extremities injury frequency information regarding the workers occupational experience was provided for 3,168 worker injuries. As Table 499 shows, laborers had over 56% (n = 1.783) of the injuries to the lower extremitie s. Foreman level workers (n = 337), apprentices (n = 299), and journeyman level workers (n = 272) sustained over 28% total, of the injuries to the lower extremities. Field supervisors represente d around five % (n = 163) of the workers with lower extremities injuries. Workers at the helper or assistant level (n = 138), administrative (n = 105), and professional (n = 71) experience levels represented about 10% total, of the workers with injuries to the lower extremities. Injury severity means were compared among th e eight occupational experience levels for injuries to the lower extremities. Injury severity scores by experience level were provided for 3,137 workers with lower extremity injuries. The results of the Le vene test of homogeneity of injury severity score variances for the eight expe rience levels did not allo w for an assumption of equal variances, L (7, 3,129) = 9.36, p < 0.001. The results of the subsequent Welch test of equality of lower extremities injury severity m eans indicated that at le ast one general cause of

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324 injury group was significantly differe nt from another group, F (7, 482.34) = 4.00, p < 0.001. This was confirmed by the results of the Tukeys b range test. Table 499. Occupational experience level of workers with lower extremity injuries. Occupational experience level Numb er of injuries % Cumulative % Laborer 1,783 56.28% 56.28% Foreman 337 10.64% 66.92% Apprentice 299 9.44% 76.36% Journeyman 272 8.59% 84.94% Field supervisor 163 5.15% 90.09% Helper/assistant 138 4.36% 94.44% Administrator 105 3.31% 97.76% Professional 71 2.24% 100.00% Total 3,168 100.00% Output of the Tukeys b test provided a ranking of the general cause of injury groups by their respective lower extremities injury severity means (see Figure 4163). Lower extremities injuries to journeymen had the highest injury severity mean ( = 1.49), followed by injuries to foremen ( = 1.48), helpers and assistants ( = 1.39), laborers ( = 1.38), apprentices ( = 1.37), field supervisors ( = 1.36), professionals ( = 1.35), administrative personnel ( = 1.20). The Tukeys test identified two homogeneous subsets of injury severity means for injuries to the lower extremities between the eight occupational experience levels. Experience levels within each subset did not have lower extremities injury se verity means that were significantly different, at p 0.05, from one another (see Figure 4163). From the arrangements of the homogeneous gr oups shown in Figure 4163, specific and significant at p 0.05, differences between the experience leve ls of severity means for injuries to the lower extremities were differentiated (see Fi gure 4164). Journeyman and foreman level workers showed a significantly greater, at p 0.05, severity mean than administrative personnel for injuries to the lower extremities.

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325 1.20 (.49) 1.35 (.59) 1.36 (.62) 1.37 (.58) 1.38 (.60) 1.39 (.60) 1.48 (.68) 1.49 (.64) 0.000.200.400.600.801.001.201.401.60 Administrative (n = 104) Professional (n = 71) Field Supervision (n = 159) Apprentice (n = 297) Laborer (n = 1768) Helper/Assistant (n = 133) Foreman (n = 334) Journeyman (n = 271) Injury Severity Mean (Standard Deviation) Figure 4163. Comparison of injury severity m eans by occupational experi ence level of workers with lower extremity injuries. 1.49 (.64) 1.48 (.68) 1.39 (.60) 1.38 (.60) 1.37 (.58) 1.36 (.62) 1.35 (.59) 1.20 (.49) 0.000.200.400.600.801.001.201.401.60 Administrative (n = 104) Professional (n = 71) Field Supervision (n = 159) Apprentice (n = 297) Laborer (n = 1768) Helper/Assistant (n = 133) Foreman (n = 334) Journeyman (n = 271) Injury Severity Mean (Standard Deviation) Figure 4164. Differences of injury severity m eans by occupational experience levels of workers with lower extremity injuries. Age The relationship between age and injuries to the lower extremities was explored in two ways. First, workers with lower extremities injuries were compared by their respective age groups. With the exception of the under 20 and over 69 age groups, each of the age groups represented ten-year spans. Injury frequencie s were compared between the age groups. Second, lower extremity injury severity means were compared between the age groups.

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326 Data for injuries to the lower extremities by the worker age were provided for 2,949 worker injuries (see Table 4100). Almost 29% (n = 1,239) of the injuries to the lower extremities were experienced by workers betwee n 40 and 49 years of age. Around 27% (n = 792) of the injuries were to workers 30 to 39 year s old. Twenty-five % (n = 749) of the lower extremities injuries occurred to workers 20 to 29 years old. Workers aged 50 to 59 years sustained around 14% (n = 423) of the injuries to the lower extremities. Workers under 20 years old (n = 62) and aged 60 to 69 years (n = 86) expe rienced just over 5 % total, of the injuries to the lower extremities. Table 4100. Age of workers with injuries to lower extremities. Age group (years) Number of injuries% Cumulative % 40 49 837 28.38% 28.38% 30 39 792 26.86% 55.24% 20 29 749 25.40% 80.64% 50 59 423 14.34% 94.98% 60 69 86 2.92% 97.90% Under 20 62 2.10% 100.00% Total 2,949 100.00% Lower extremity injury severity means were compared among the six age groups. Injury severity scores were provided for 2,907 workers with injuries to the lower extremities. The results of the Levene test of ho mogeneity of injury severity score variances for the six age groups did not allow for an assumption of equal variances, L (5, 2,901) = 30.27, p < 0.001. The results of the subsequent Welch test of equality of lower extremities injury severity means indicated that at least one age group was significantly di fferent from another group, F (5, 379.86) = 12.40, p < 0.001. This was confirmed by the results of the Tukeys b range test. The results of the Tukeys b test provided a ranking of the age gr oups by their respective lower extremities injury severity means (see Figu re 4165). Workers 50 to 59 years of age had the highest severity mean ( = 1.45), followed by workers 40 to 49 ( = 1.43), 60 to 69 ( =

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327 1.42), and 30 to 39 ( = 1.38) years old. Worker s under the age 20 ( = 1.29) and between 20 and 29 years old ( = 1.24) had the two lowest in jury severity means for injuries to the lower extremities among the age groups. The results of the Tukeys b range test identified two homogeneous subsets of severity means for lower extremities injuries among the age groups. 1.24 (.52) 1.29 (.52) 1.38 (.61) 1.42 (.73) 1.43 (.61) 1.45 (.64) 1.101.151.201.251.301.351.401.451.50 20 29 (n = 736) Under 20 (n = 62) 30 39 (n = 780) 60 69 (n = 86) 40 49 (n = 825) 50 59 (n = 418) Injury Severity Mean (Standard Deviation) Figure 4165. Comparisons of injury severity means by age of workers with lower extremity injuries. Specific lower extremities injury severity m ean differences were discerned from the homogeneous subsets displayed in Figure 4165 As illustrated in Figure 4166, workers aged 40 to 69 years had a significantly lower, at p 0.05, lower extremity injury severity mean than for workers between 20 and 29 years of age. 1.45 (.64) 1.43 (.61) 1.42 (.73) 1.38 (.61) 1.29 (.52) 1.24 (.52) 1.101.151.201.251.301.351.401.451.50 20 29 (n = 736) Under 20 (n = 62) 30 39 (n = 780) 60 69 (n = 86) 40 49 (n = 825) 50 59 (n = 418) Injury Severity Mean (Standard Deviation) Figure 4166. Differences of injury severity means by age of workers with lower extremity injuries. The mean ages of workers with injuries to the lower extremities were compared by the specific body part impacted by the injury. The resu lts of the Levene test of homogeneity of age variances between the specific body parts of the lower extremities allowed for an assumption of

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328 equal variances, L (8, 2,940) = 1.76, p > 0.07. Subsequently, the results of the ANOVA test indicated that at least one of body parts of th e lower extremities had a significantly different mean age from one of the other body parts, F (8, 2,940) = 11.66, p < 0.001. The results of the Tukeys b range test confirmed this test result and enabled ranking the body parts by the workers respective mean ag es (see Figure 4167). Among injuries of to the lower extremities, work ers with hip injuries had the highest mean age, = 41.60 years. This was followed by worker s with knee injuries ( = 39.89), lower leg ( = 39.70), great toe ( = 38.90), toe ( = 38.40), uppe r leg ( = 36.82), multiple injuries ( = 36.58), ankle ( = 36.10), and foot injuries ( = 35.58). As illustrated in Figure 4167, the Tukeys b test also identified two homogeneous s ubsets of body parts of th e lower extremities, in which mean ages were not significantly different at p 0.05. 35.58 (10.91) 36.10 (10.48) 36.58 (10.65) 36.82 (11.65) 38.40 (11.79) 38.90 (12.81) 39.70 (11.18) 39.89 (11.14) 41.60 (13.15) 323334353637383940414243 Foot (n = 599) Ankle (n = 588) Multiple Injuries (n = 33) Upper Leg (n = 125) Toe (n = 106) Great Toe (n = 41) Lower Leg (n = 374) Knee (n = 1021) Hip (n = 62) Mean Age (Standard Deviation) Figure 4167. Comparison of mean ages by in jured body parts of lower extremity injuries. From the two homogeneous subsets, it was dis cerned that among workers with injuries to the lower extremities, those with hip injuries had a significantly greater mean age, at p 0.05,

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329 than workers experiencing multiple lower extremity injuries, ankle injuries, and foot injuries (see Figure 4168). 41.60 (13.15) 39.89 (11.14) 39.70 (11.18) 38.90 (12.81) 38.40 (11.79) 36.82 (11.65) 36.58 (10.65) 36.10 (10.48) 35.58 (10.91) 323334353637383940414243 Foot (n = 599) Ankle (n = 588) Multiple Injuries (n = 33) Upper Leg (n = 125) Toe (n = 106) Great Toe (n = 41) Lower Leg (n = 374) Knee (n = 1021) Hip (n = 62) Mean Age (Standard Deviation) Figure 4168. Differences of mean ages by injured body parts of the lower extremities. Job Tenure The number of days between the time an injure d worker was hired and the time that injured worker sustained an injury to the lower extrem ities (i.e., job tenure) was explored. Information regarding the frequency of injuries to the lowe r extremities by the nine job tenure categories, shown in Table 4101, was provided for 7,052 worker injuries. Workers who had been employed for 181 to 365 days (n = 1,185) and those employed for 91 to 180 days (n = 1,091) each accounted for around 16% of the injuries to the lower extremities. N early 14% of the lower extremities injuries were experienced by workers in their first 15 days of employment (n = 1,974) and 12% were sustained by workers employed 31 to 60 days (n = 1,866). Ten % of the injuries to the lower extremities were among wo rkers employed from 366 to 730 days (n = 729). Workers injured between the 16th and 30th day of employment (n = 672), and those injured

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330 between their 61st and 90th day of employment (n = 637) each made up about 19% of the lower extremity injures. Workers with injuries to the lower extremities who were employed two or more years prior to being injured accounted for just over 13% of the lower extremities injuries. Table 4101. Job tenure of worker s with lower extremity injuries. Job tenure Number of injuries % Cumulative % 181 to 365 days 1,185 16.80%16.80% 91 to 180 days 1,091 15.47%32.27% 0 to 15 days 974 13.81%46.09% 31 to 60 days 866 12.28%58.37% 366 to 730 days (1 to 2 years) 729 10.34%68.70% 16 to 30 days 672 9.53%78.23% 61 to 90 days 637 9.03%87.27% 731 to 1460 days (2 to 4 years) 460 6.52%93.79% > 1461 days (> 4 years) 438 6.21%100.00% Total 7,052 100.00% Job tenure categories were compared by their respective severity means for injuries to lower extremities. The results of the Levene test of homogeneity of trunk injury severity score variances did not allow for the assumption of equal variances between the nine job tenure categories, L (8, 6,967) = 2.40, p < 0.02. Subsequently, the Welch te st was performed to test the equality of lower extremities injury severity m eans between these categories. The results of this test indicated that none of j ob tenure categories had an injury severity mean that was significantly different from one of the other categories, F (8, 2,526) = 0.83, p > 0.50. This result was confirmed by the results the of the Tukeys b range test. Figure 4169 displays the results of the Tukeys b range test. The single homogeneous subset indicates that, at p 0.05, none of the job tenure categor ies had a significantly different lower extremity injury severity mean from any of the other categories. Workers with over two years of employment ( = 1.50) prior to experien cing an injury to a lower extremity had the highest severity mean for lower extremity injuries than all of the other j ob tenure categories. This

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331 was followed by workers with more than four ye ars of employment prior to having their injury ( = 1.48) and workers with one to two year s of experience ( = 1.47). Injured workers employed between 91 and 180 days had the lowest inju ry severity mean ( = 1.42) for injuries to the lower extremities. 1.42 (.61) 1.43 (.65) 1.44 (.64) 1.45 (.67) 1.45 (.62) 1.46 (.64) 1.47 (.62) 1.48 (.63) 1.50 (.70) 1.381.401.421.441.461.481.501.52 91 to 180 Days (n = 1079) 61 to 90 Days (n = 628) 16 to 30 Days (n = 665) 181 to 365 Days (n = 1169) 0 to 15 Days (n = 960) 31 to 60 Days (n = 858) 366 to 730 Days (1 to 2 Years) (n = 725) > 1461 Days (> than 4 Years) (n = 435) 731 to 1460 Days (2 to 4 Years) (n = 457) Injury Severity Mean (Standard Deviation) Figure 4169. Comparison of injury severity means by job tenure of workers with lower extremity injuries. Month of Occurrence of Injury Based on information provided for 9,193 cases t he distribution of in juries to the lower extremities was examined by the month of the year during which the injury had occurred. Table 4102 shows the distribution of injuries to the lower extremities for each of the twelve months. Each of the months of August (n = 889), Oct ober (n = 873), and July (n = 867) accounted for slightly more than 9 % of the lower extremity in juries to workers. June (n = 818), March (n = 779), September (n = 767), and April (n = 746) had slightly more than eight % of the lower extremity injuries. December (n = 694), May (n = 689), November (n = 689), and February (n = 654) were associated with slightly less than 7 % total of the lower extremity injuries to workers.

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332 Injury severity for injuries to the lower extremities by the month of the injury was examined by ranking the months by their respective injury seve rity means and subsequently comparing the injury severity means between the months to identify possible differences, significant at p 0.05. Severity scores, by month of the injury occurrence, were provided for 9,080 worker injuries to the lower extremities. The re sults of an initial Levene test did not allow Table 4102. Month of occurren ce of lower extremity injuries. Month of injury occurrence Numb er of injuries % Cumulative % August 889 9.67% 9.67% October 873 9.50% 19.17% July 867 9.43% 28.60% June 818 8.90% 37.50% March 779 8.47% 45.97% September 767 8.34% 54.31% April 746 8.11% 62.43% January 728 7.92% 70.35% December 694 7.55% 77.90% May 689 7.49% 85.39% November 689 7.49% 92.89% February 654 7.11%100.00% Total 9,193 100.00% for an assumption of equal injury severity score variances between the twelve months, L (11, 9,068) = 2.69 p < 0.003. The results of the subsequent We lch test indicated that none of the months had a significantly different lower extremities injury severity mean of any of the other months, F (11, 3,529.01) = 1.71, p > 0.06. The results of the Tukeys b range test were used to rank the months of occurrence lower extremity injuries severity mean s, (see Figure 4170). Injuries to the lower extremitie s which occurred in February ( = 1.46), November ( = 1.43), and June ( = 1.43) had the highest severity means. These were followed by the months of August ( = 1.41), January ( = 1.40), December ( = 1.39), July ( = 1.39), October ( = 1.38), March ( = 1.38), April ( = 1.38), and Ma y ( = 1.38), and September ( = 1.36).

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333 Day of the Week of Occurrence of Injury The possible relationship between injuries to th e lower extremities and the day of the week on which these injuries occurred was explored. Injury frequency da ta for lower extremity injuries 1.36 (.60) 1.38 (.60) 1.38 (.60) 1.38 (.62) 1.38 (.64) 1.39 (.64) 1.39 (.63) 1.40 (.62) 1.41 (.63) 1.43 (.62) 1.43 (.63) 1.46 (.63) 1.301.321.341.361.381.401.421.441.461.48September (n = 758) May (n = 686) April (n = 737) March (n = 767) October (n = 865) July (n = 855) December (n = 680) January (n = 718) August (n = 877) June (n = 812) November (n = 681) February (n = 644)Injury Severity Mean (Standard Deviation) Figure 4170. Comparison of injury severity m eans by month of occurren ce of lower extremity injuries. by each day of the week is displayed in Table 4103. About 19% of the lower extremity injuries occurred either on a Wednesday (n = 1,805), Tu esday (n = 1,772), Monday (n = 1,723), or Thursday (n = 1,703). Around 16% of the lower extr emities injuries occurred on a Friday (n = 1,496). Slightly more than seven % of lower ex tremity injuries occurred during the weekend, namely on Saturdays (n = 540) and Sundays (n = 154). Table 4103. Day of the week of o ccurrence of lower extremity injuries. Day of the week of occurrence Nu mber of injuries % Cumulative % Wednesday 1,805 19.63% 19.63% Tuesday 1,772 19.28% 38.91% Monday 1,723 18.74% 57.65% Thursday 1,703 18.52% 76.18% Friday 1,496 16.27% 92.45% Saturday 540 5.87% 98.32% Sunday 154 1.68% 100.00% Total 9,193 100.00%

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334 Injury severity for injuries to the lower extremities by the day of the week on which the injury occurred was examined by ranking the days of the week by their respective injury severity means and subsequently comparing the lower extr emity injury severity means between the days to identify possible differences, significant at p 0.05. Severity scores, by day of the injury, were provided for 9,080 worker injuries to the lowe r extremities. The results of an initial Levene test did not allow for an assumption of equal lo wer extremity injury score variances between the seven days of the week, L (6, 9,073) = 4.24, p < 0.001. The results of the subsequent Welch test indicated that none of the days of the week had a significantly di fferent lower injury severity mean of any of the other days of the week, F (6, 1,588.75) = 1.69, p > 0.10. The results of the Tukeys b range test were used to rank the days of the week of occurrence of lower extremity inju ries severity means, (see Figure 4171). Injuries to the lower extremities occurring on Sundays ( = 1.49) show ed the highest injury severity mean among days on the week on which lower extremities injuries occurred. This was followed by injuries experienced on Saturdays ( = 1.46), Mondays ( = 1.41), Thursdays ( = 1.40), Fridays ( = 1.39), Wednesdays ( = 1.39), Tuesdays ( = 1.38). 1.38 (.61) 1.39 (.59) 1.39 (.62) 1.40 (.62) 1.41 (.63) 1.46 (.66) 1.49 (.69) 1.301.351.401.451.50 Tuesday (n = 1755) Wednesday (n = 1786) Friday (n = 1474) Thursday (n = 1680) Monday (n = 1697) Saturday (n = 535) Sunday (n = 153) Injury Severity Mean (Standard Deviation) Figure 4171. Comparison of injury severity m eans by day of the week of occurrence of lower extremity injuries. Multiple Body Regions or Body Systems Injury severity to multiple body regions or body systems (MBRBS) was examined by the specific body part injured (e.g., knee) the nature of the injury (e .g., laceration), the general cause

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335 of the injury (e.g., fall or slip ), the occupational work area in which the injured worker was working at the time of the injury (e.g., carpentry), the injured wo rkers occupational experience level (e.g., apprentice), the job tenure of the injured worker at the time of the injury, the month of the year and day of the week on which the injury occurred, and the age of the injured worker at the time of the injury. A comparison of mean ages by specific body parts injured was also performed. Body Part Information regarding the specific injure d body parts involving MBRBS injuries was provided for 1,699 worker injuries. As Table 4104 shows, injuries to multiple body parts constituted over 91% (n = 1,557) of the MBRBS inju ries. The remaining injuries were associated with one or more body systems, such as respirat ory system and circulatory system, skeletal and nervous systems. Table 4104. Injured body parts of MBRBS injuries. Body part Number of injuries % Cumulative % Multiple body regions 1,557 91.64% 91.64% Body systems 142 8.36% 100.00% Total 1,699 100.00% Injury severity scores were provided for 1,687 worker injuries to MBRBS. Injuries to multiple body parts had a higher injury severity mean ( = 1.60) than injuries associated with body systems (see Figure 4172). The results from an independent t-test for quality means show that this difference was not statis tically significan t, t (1,685) = 0.08, p > 0.90. 1.59 (.86) 1.60 (.80) 1.591.591.591.591.601.601.60 Body Systems (n = 140) Multiple Body Parts (n = 1547) Injury Severity Mean (Standard Deviation) Figure 42. Comparison of injury severity means by injured body parts of MBRBS injuries.

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336 Nature of Injury Information regarding the MBRBS injuries by the nature of the injury was provided for 1,526 worker injuries (see Table 4105). The top ten nature of injury categories accounted for 86% of the MBRBS injuries. These included mu ltiple injuries (n = 488), strains (n = 234), contusions (n = 220), heat prostration (n = 73), el ectric shock (n = 55), burns (n = 52), dermatitis (n = 50), occupational disease NOC (n = 50), in flammations (n = 48), a nd fractures (n = 46). Table 4105 shows the distribution of the MBRBS injuries by nature of injury. Injury severity scores were provided for 1,514 workers with MBRBS injuries for 24 nature of injury categories. Injury se verity means were compared for each of these categories. The Table 4105. Nature of injury to multiple body regions and body systems. Nature of injury Number of injuries % Cumulative % Multiple injuries 488 31.98% 31.98% Strain 234 15.33% 47.31% Contusion 220 14.42% 61.73% Heat prostration 73 4.78% 66.51% Electric shock 55 3.60% 70.12% Burn 52 3.41% 73.53% Dermatitis 50 3.28% 76.80% Occupational disease NOC 50 3.28% 80.08% Inflammation 48 3.15% 83.22% Fracture 46 3.01% 86.24% Laceration 38 2.49% 88.73% Sprain 26 1.70% 90.43% Chemical poisoning 22 1.44% 91.87% Respiratory disorder 18 1.18% 93.05% Mental stress/disorder 18 1.18% 94.23% Poisoning NOC 17 1.11% 95.35% Puncture 17 1.11% 96.46% Syncope 16 1.05% 97.51% Crushing 11 0.72% 98.23% Infection 10 0.66% 98.89% Rupture 10 0.66% 99.54% Severance 3 0.20% 99.74% Dislocation 2 0.13% 99.87% Asphyxiation 2 0.13% 100.00% Total 1,526 100.00%

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337 results from the Leven test of homogeneity of vari ances of severity scores between the nature of injury categories did not allow for an assumpti on of equal variances of scores between the categories L (23, 1,490) = 6.52, p < 0.001. The results from the subsequent Welch test of equality of injury severity means indicated that at least one of the na ture of MBRBS injury categories had a significantly different injury severity mean than one of the other categories, F (23, 56.88) = 14.16, p < 0.001. This was confirmed by the results from the Tukeys b range test which identified five homogeneous subsets of in jury severity means am ong the 24 nature of MBRBS categories. Injury severity means between the nature of injury categories within each subset did not significantly differ from one another at p 0.05. From the arrangement of the subsets, the following four relations hips were discerned (see Table 4105 for the listing of all the nature of injury categories associated with MBRBS injuries): Crushing, as a nature of MBRBS injuries, had the highest injury severity mean ( = 3.64, = 1.63). Crushing injuries had a signifi cantly greater inju ry severity mean, at p 0.05, than the remaining nature of injury categories, except ruptures. Ruptures ( = 2.80, = 0.42) had a significantly grea ter MBRBS injury severity mean, at p 0.05, than strains, contusions, he at prostration, electric shocks, dermatitis, occupational disease NOC, inflammations, lacerations, sprains, chemical poisonings, respiratory disorders, general poisonings, punctures, syncope, and infections. Dislocations ( = 2.50, = 0.71) had a significantly grea ter injury severity mean, at p 0.05, than the following nature of MBRBS injuries: punctures, syncope, heat prostrations, infections, inflammations, general poisonings, and dermatitis. Severances ( = 2.33, = 0.58) showed a greater MBRBS injury severity mean, at p 0.05, than inflammation, general poisoning, and dermatitis. General Cause of Injury From information provided for 2,246 worker injuries, the multiple body regions and body systems (MBRBS) injury distribution by general cause of injury categories was generated and

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338 ranked in descending order of frequency (see Ta ble 4106). Nearly 30% of the MBRBS injuries were caused by a slip or fall (n = 664). Strains were attributed as the cause of injury for 20% (n = 457) of the MBRBS injuries. Around 16% of the workers with MBRBS injuries had sustained these injuries by the absorption, ingestion, or in halation of a substance (n = 348). Ten % of the MBRBS injuries were caused by the workers be ing struck by an objec t (n = 229). Around 6% were caused by burns (n = 142). Five % were cause d when the workers struck against or stepped on an object (n = 115), followed by involvement with a motor vehicle (4.59%, n = 103), and animal bite or insect sting (3.16%, n = 71).The remaining 5% of the MBRBS injuries were caused by a combination of having been Caught in or between an object or objects (n = 49), cut, punctured, or scraped (n = 47), and foreign matter (n = 21). Table 4106. General cause of multiple body region or body systems (MBRBS) injuries. General cause of injury Number of injuries % Cumulative % Fall or slip 664 29.56% 29.56% Strain 457 20.35% 49.91% Absorption, ingestion, or inhalation 348 15.49% 65.41% Struck by 229 10.20% 75.60% Burn 142 6.32% 81.92% Striling against or stepping on 115 5.12% 87.04% Motor vehicle 103 4.59% 91.63% Animal or insect bite or sting 71 3.16% 94.79% Caught in or between 49 2.18% 96.97% Cut, puncture, or scrape 47 2.09% 99.07% Foreign Matter 21 0.93% 100.00% Total 2,246 100.00% Injury severity scores relative to the eleven general cause of injury categories were provided for 2,210 workers with MBRBS injuries. Injury severity means were compared for each of these categories. The results from the Leven test of homogeneity of variances of severity scores between the general cause of injury categ ories did not allow for an assumption of equal variances of scores between the categories L (10, 2,199) = 12.07, p < 0.001. The results from

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339 the subsequent Welch test of equality of injury severity means indicated that at least one of the general cause of MBRBS injury ca tegories had a significantly different injury severity mean than one of the other categor ies, F (10, 301.19) = 12.34, p < 0.001. This was confirmed by the results from the Tukeys b range test which identified three homogeneous subsets of injury severity means among the eleven general cause of MBRB S injury categories. Injury severity means between the general cause of in jury categories within each su bset did not significantly differ from one another, at p 0.05. From the arrangement of the subsets, the following two relationships were discerned (see Table 4106 for the listing of all the general cause of injury categories associated with MBRBS injuries): MBRBS injuries caused by being Caught in or between an object or objects ( = 1.51, = 1.20), a fall or slip ( = 1.68, =0.86), being struck by an object ( = 1.68, = 0.95), and by involvement with a motor vehicle ( = 1.62, = 0.78), demostrated injury severity means significantly greater, at p 0.05, than MBRBS injuries caused by cuts, punc tures, or scrapes ( = 1.20, = 0.40), an animal bite or insect sting ( = 1.18, = 0.62), and foreign matter ( = 1.14, = 0.48). Injuries caused by having been Caught in or between an object or objects also had a significantly greater MBRBS injury severity mean, at p 0.05, than that of injuries caused by having struck against or stepped on an object (= 1.41, = 0.63), and from the absorption, ingestion, or inhalation of a substance ( = 1.31, = 0.68). Occupational Work Area The occupational work area categories identified the specific work area in which each injured worker was involved at the time of the MBRBS injury. Table 4107 displays the distribution the 2,307 MBRBS injuries among 41 o ccupational work areas. Almost 75% of the MBRBS injuries were associated with workers working in the following ten occupational areas at the time of injury: electrical (n = 386), carpentry (n = 293) iron and steel work (n = 238), technical repair or maintenance (n = 151), concrete work (n = 146), masonry (n = 121), plumbing

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340 Table 4107. Occupational work areas of wo rkers with multiple body regions or body systems (MBRBS) injuries. Occupational work area Number of injuries % Cumulative % Electrical 386 16.73% 16.73% Carpentry 293 12.70% 29.43% Iron/steel 238 10.32% 39.75% Technical repair or maintenance 151 6.55% 46.29% Concrete 146 6.33% 52.62% Masonry 121 5.24% 57.87% Plumbing 110 4.77% 62.64% Equipment/machinery operation 103 4.46% 67.10% Pipe fitting 93 4.03% 71.13% Drywall 83 3.60% 74.73% Sheet metal 63 2.73% 77.46% Painting and plastering 61 2.64% 80.10% Boilermaker 56 2.43% 82.53% Welding 40 1.73% 84.27% Supervising 37 1.60% 85.87% Driving 34 1.47% 87.34% Insulating 31 1.34% 88.69% Lineman 28 1.21% 89.90% Managing 26 1.13% 91.03% Millwright 25 1.08% 92.11% Roofing 19 0.82% 92.93% Clerical 18 0.78% 93.71% Inspecting 17 0.74% 94.45% Steam fitting 14 0.61% 95.06% Security 13 0.56% 95.62% Glazing 12 0.52% 96.14% Engineering 12 0.52% 96.66% Conveyor systems 10 0.43% 97.10% Sprinkler fitting 10 0.43% 97.53% HVAC/refrigeration 10 0.43% 97.96% Flooring, tile, carpeting 8 0.35% 98.31% Scaffold erection 7 0.30% 98.61% Flagging 6 0.26% 98.87% Lathing 5 0.22% 99.09% Landscaping 4 0.17% 99.26% Hod carrying 4 0.17% 99.44% Waterproofing 4 0.17% 99.61% Surveying 3 0.13% 99.74% Rigging 2 0.09% 99.83% Material handling 2 0.09% 99.91% Field engineering 2 0.09% 100.00% Total 2,307 100.00%

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341 (n = 110), equipment or machinery operations (n = 93) pipe fitting (n = 83), and drywall work (n = 63). See Table 4-107 for all the occupational wo rk areas associated with MBRBS injuries. Injury severity scores, by the occupationa l work areas associated with the MBRBS injuries, were provided for 2,285 worker injuries Based on this information, injury severity means were generated for and compared between the 41 occupational work areas. The results of the Levene test of homogeneity of injury seve rity score variances be tween the 42 occupational areas did not allow for the assumption of equal variances, L (40, 2,244) = 3.02, p < 0.001. The results of the Welch test of equality of results su ggested that at least one of the work areas could have had an injury severity mean for MBRBS injuri es that was significantly different than one of the other work areas, F (40, 87.10) = 1.87, p < 0.01. However, this was not confirmed by the results of the Tukeys b range test. The single homogeneous subset of injury se verity means resulti ng from the Tukeys b range test indicated that none of the work areas had a MBRBS severity mean that was significantly different, at p 0.05, from any of the other work areas. The occupational work areas associated with the ten hi ghest severity means for MBRBS injuries were as follows: hod carrying ( = 1.75, = 0.50), roofing ( = 1.63, = 0.68), carpentry ( = 1.63, = 0.85), working with or as a lineman ( = 1.59, = 0.93), engineering ( = 1.58, = 1.16), glazing ( = 1.58, = 1.16), steam fitting ( = 1.57, = 1.09), driving ( = 1.56, = 1.05), equipment or machinery operation ( = 1.55, = 0.89), and iron and steel work ( = 1.55, = 0.81). Occupational Experience Level Multiple body regions and body systems injury information regarding the workers occupational experience was provided for 3,168 worker injuries. As Table 4108 shows, laborers had over 56% (n = 1.783) of the MBRBS injuries. Foreman level workers (n = 337), apprentices (n = 299), and journeyman level workers (n = 27 2), sustained over 28% of the MBRBS injuries.

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342 Field supervisors represented around five % (n = 163) of the workers with MBRBS injuries. Workers at the helper or assist ant level (n = 138), administrativ e (n = 105), and professional (n = 71) experience levels represented about 10% of the workers with MBRBS injuries. Injury severity means were compared among th e eight occupational experience levels for MBRBS injuries. Injury severity scores by expe rience level were provided for 877 workers with MBRBS injuries. The results of the Levene test of homogeneity of in jury severity score variances for the eight experien ce levels allowed for an assumption of equal variances, L (7,7, 869) = 0.47, p > 0.85. The results of the subsequent ANOVA test indicated that none of the experience levels had a significan tly different severity mean fro m another level, F (7, 869) = 5.76, p > 1.48. This was confirmed by the re sults of the Tuke ys b range test. Table 4108. Occupational experience level of workers with injuries to multiple body regions and body systems. Occupational experience level Numb er of injuries % Cumulative % Laborer 539 60.36% 60.36% Foreman 78 8.73% 69.09% Journeyman 59 6.61% 75.70% Apprentice 56 6.27% 81.97% Helper/assistant 48 5.38% 87.35% Administrator 44 4.93% 92.27% Field supervisor 39 4.37% 96.64% Professional 30 3.36% 100.00% Total 893 100.00% The single homogeneous subset of injury severity means resulti ng from the Tukeys b range test indicated that none of the experience levels had an MBRBS severity mean that was significantly different, at p 0.05, than any of the other experi ence levels. Journeymen ( = 1079, = 0.83) were associated with the highest se verity means for MBRBS injuries. This was followed by apprentices ( = 1.58, = 0.76), professionals ( = 1.53, = 0.82), laborers ( = 1.51, = 0.70), helpers and assistants ( = 1.50, = 0.78), field supervisors ( = 1.49, = 0.60), foremen ( = 1.44, = 0.83), and administrative personnel ( = 1.41, = 0.76).

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343 Age The relationship between age and injuries to MBRBS was explored in two ways. First, workers with MBRBS injuries were compared by their respective age groups With the exception of the under 20 and over 69 age groups, each of the ag e groups represented ten-year spans. Injury frequencies were compared between the age groups. Second, MBRBS injury severity means were compared between the age groups. Data for MBRBS injuries by worker age were provided for 1,137 worker injuries (see Table 4109). Almost 29% (n = 333) of the MB RBS injuries were sustained by workers between 30 and 39 years of age. Twenty-six % (n = 297) of the injuries were to workers 40 to 49 years old. Nearly 25% (n = 162) of the MBRBS injuries occurred to workers 50 to 59 years old. Workers aged 60 to 69 years sustained around 4% (n = 42) of the MBRBS injuries. Workers under 20 years old (n = 20) experienced ju st under 2 % of the MBRBS injuries. Table 4109. Age of workers with MBRBS injuries. Age (years) Number of injuries % Cumulative % 30 39 333 29.29% 29.29% 40 -49 297 26.12% 55.41% 20 29 283 24.89% 80.30% 50 59 162 14.25% 94.55% 60 69 42 3.69% 98.24% Under 20 20 1.76% 100.00% Total 1,137 100.00% Multiple body region and body systems injury severity means were compared among the six age groups. Injury severity scores were provided for 1,123 workers with MBRBS injuries. The results of the Levene test of homogeneity of injury severity score variances for the six age groups did not allow for an assumption of equal variances, L (5, 1,117) = 13.12, p < 0.001. The results of the subsequent Welch test of equality of MBRBS injury severity means indicated that at least one age group was significantly di fferent from another group, F (5, 156.97) = 10.78, p <

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344 0.001. This was confirmed by the results of the Tukeys b range test. Three homogeneous subsets of age groups by MBRBS injury severity means were identified by the Tukeys b range test. From the arrangement of these subsets the following was discerned: Workers between 60 and 69 years old had a significantly larger injury severity mean ( = 1.88, = 1.02), at p 0.05, for MBRBS injuries than each of the remaining age groups. Workers 40 to 49 ( = 1.38, = 0.74) and 50 to 59 ( = 1.45, = 0.69) years old were associated with MBRBS injury se verity means significantly greater, at p 0.05, than MBRBS injuries to wo rkers under 20 years old ( = 1.05, = 0.22). The results from Kendalls tau b test for correlation be tween age and MBRBS injury severity means showed that age had a slight, though significant, positive correlation with the injury severity mean of MBRBS injuries, r (1,135), p < 0.01. The mean ages of workers with MBRBS inju ries were compared between the two body parts associated with multiple body parts or body sy stems injuries using the independent t-test. The results from this test did not indicate a significant mean age difference between multiple body parts ( = 41.50 years, = 11.62) and body systems ( = 40.77 years, = 10.83), t (266) = 0.40, p > 0.60. Job Tenure The number of days between the time an injure d worker was hired and the time that injured worker sustained a MBRBS injury was explored. In formation regarding the frequency of injuries to MBRBS by the nine job te nure categories, shown in Table 110, was provided for 2,259 worker injuries. Workers who had been employed for 91 to 365 days (n = 687) accounted for 30% of the MBRBS injuries. Nearly 14% of the MBRBS injuries were sustained by workers in their first 15 days of employment (n = 309) and 13% were sustained by workers employed 31 to 60 days (n = 291). Ten % of the MBRBS injuries were among workers employed from 366 to

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345 730 days (n = 237). Workers injured between the 16th and 30th day of employment (n = 222) and those injured between their 61st and 90th day of employment (n = 209) comprised about 9% of the MBRBS injures. Workers with MBRBS injuries who were employed two or more years prior to being injured accounted for 13% of the MBRBS injuries. Job tenure categories were compared by th eir respective severity means for MBRBS injuries. The results of the Levene test of homogeneity of MBRBS injury severity score variances allowed for the assumption of equal variances between the nine job tenure categories, L (8, 2,217) = 1.90, p > 0.05. Subsequently, the ANOVA test wa s performed to test the equality of MBRBS injury severity means between these cate gories. The results of this test indicated that none of the job tenure categories ha d an injury severity mean that was significantly different from any of the other ca tegories, F (8, 2,217) = 4.13, p > 0.54. This result was confirmed by the results the of the Tukeys b range test. Table 4110. Job tenure of wo rkers with MBRBS injuries. Job tenure Number of injuries % Cumulative % 91 to 180 days 355 15.71% 15.71% 181 to 365 days 332 14.70% 30.41% 0 to 15 days 309 13.68% 44.09% 31 to 60 days 291 12.88% 56.97% 366 to 730 days (1 to 2 years) 237 10.49% 67.46% 16 to 30 days 222 9.83% 77.29% 61 to 90 days 209 9.25% 86.54% 731 to 1460 days (2 to 4 years) 157 6.95% 93.49% > 1461 days (Greater than 4 years) 147 6.51% 100.00% Total 2,259 100.00% Month of Occurrence of Injury Based on information provided for 3,433 cases t he distribution of MBRBS injuries was examined by the month of the year during which the injuries had occurred. Table 4111 shows the distribution of the MBRBS injuries for each of the twelve months. The highest frequency of injuries occurred in the summer months of Ju ly (n = 401), August (n = 385), September (n=

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346 318), and June (n = 304), accounted for 41% of the MBRBS injuries. At nearly 7% of the MBRBS injuries each, the months of January (n = 240), November (n = 239), April (n = 235), and December (n = 223) had the lowe st frequency of MBRBS injuries. Injury severity for MBRBS injuries by month of injury occurrence was examined by ranking the months by their respec tive injury severity means a nd subsequently comparing the injury severity means between the months to identify possible diffe rences, significant at p 0.05. Severity scores, by month of injury occurr ence, were provided for 3,433 worker MBRBS injuries. The results of an initial Levene test did not allow for an assumption of equal injury severity score variances between the twelve months, L (11, 3,361) = 3.06 p < 0.001. The results of the subsequent Welch test indi cated that at least one of the m onths had a significantly different MBRBS injury severity mean from one of the other months, F (11, 1,266.05) = 1.84, p < 0.05 This was not confirmed by the results from th e Tukeys b range test. MBRBS injuries which occurred in April ( = 1.60, = 0.87), January ( = 1.55, = 0.85), and October ( = 1.54, =0.79), had the highest injury severity means. Table 4111. Month of occurrence of MBRBS injuries. Month of injury occurrence Numb er of injuries % Cumulative % July 401 11.68% 11.68% August 385 11.21% 22.90% September 318 9.26% 32.16% June 304 8.86% 41.01% October 296 8.62% 49.64% May 282 8.21% 57.85% March 267 7.78% 65.63% February 243 7.08% 72.71% January 240 6.99% 79.70% November 239 6.96% 86.66% April 235 6.85% 93.50% December 223 6.50% 100.00% Total 3,433 100.00%

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347 However, these were included with the remaining nine months in a single homogenous subset of injury severity means. This indicated that none of the months of occurrence of MBRBS injuries had a significantly differe nt severity mean, at p 0.05, from any of the other months. Day of the Week of Occurrence of Injury The possible relationship between MBRBS injuries and the day of the week on which these injuries occurred was explored. Injury frequency data for MBRBS injuries by each day of the week is displayed in Table 4112. About 19% of the MBRBS injuries occurred on a Monday (n = 671) or Thursday (n = 642). Around 18% oc curred on a Tuesday (n = 626), Wednesday (n = 616), or Friday (n = 600). Slightly more than eight % of MBRBS injuries occurred during the weekend, namely on Saturdays (n = 216) and Sundays (n = 62). Table 4112. Day of the week of occurrence of multiple body regions or body systems injuries. Day of the week of occrrence Nu mber of injuries % Cumulative % Monday 671 19.55% 19.55% Thursday 642 18.70% 38.25% Tuesday 626 18.23% 56.48% Wednesday 616 17.94% 74.42% Friday 600 17.48% 91.90% Saturday 216 6.29% 98.19% Sunday 62 1.81% 100.00% Total 3,433 100.00% Injury severity for MBRBS by the day of the week on which the MBRBS injury occurred was examined by ranking the days of the week by their respective injury severity means and subsequently comparing MBRBS injury severity means between the days to identify possible differences, significant at p 0.05. Severity scores, by day of the injury, were provided for 3,373 worker MBRBS injuries. The results of an initial Levene allowed for an assumption of equal MBRBS injury score variances between the seven days of the week, L (6, 3,366) = 1.30, p > 0.25. The results of the subsequent ANOVA test indi cated that none of the days of the week had

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348 a significantly different MBRBS in jury severity mean from any of the other days of the week, F (6, 629.60) = 0.90, p > 0.47. This was confirmed by the results of the Tukeys b range test. The results of the Tukeys b range te st ranked the days of the week of occurrence of MBRBS injuries severity means. MBRBS injuries occurring on Su ndays ( = 1.55) showed the highest injury severity mean among days on the week on which MBRBS injuries occurred. This was followed by MBRBS injuries sustained on Saturdays ( = 1.52, = 0.76), Fridays ( = 1.41, = 0.79), Tuesdays ( = 1.47, = 0.76), Mondays ( = 1.4 7, 0.73), Wednesdays ( = 1.45, = 0.69), and Thursday ( = 1.43, 0.71).

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349 CHAPTER 5 CONCLUSIONS Injury information was obtained from a large private workers compensation insurance provider for a total of 46,056 injured workers perf orming work on construction projects between 1992 and 2006. Injury frequencies from the data in my study were compared with US Bureau of Labor Statistics data for construction inju ries from 1992 through 2005 (USDOL-BLS, 2005) and Hinze, Devenport, and Giang (2006). Following these comparisons, the investigator was confident that these data were representa tive of the U.S. construction industry. The studys purpose was to demonstrate that data from a large provider of workers compensation insurance could gene rate insights about the relativ e frequency and severity of various occupational inju ries and diseases sustained in c onstruction. The study examined data relative to worker experience leve ls, age, gender, job tenure, year month, and day of the week of occurrence. The histogram of the distribution of all th e injuries by severity score was examined and injury severity means 1.10 were determined to represent lo w severity injuries, while injury severity means 1.35 were determined to be of high se verity. Severity means between 1.1 and 1.35 were considered to be of medium level of severity. Injured workers were generally young, averagin g 37 years. Injured laborers, apprentices, and helpers or assistants, tended to be younger th an injured foremen, administrative personnel, field supervisors, and professionals. Age of the injured worker had a strong effect on the severity of sustained injuries. Even though workers over 69 we re rarely injured, their injuries tended to be more severe than those sustai ned by younger workers. There was a trend of increasing injury severity with increasing age. Workers employed less than 30 days (new hires) had a disproportionate ly higher daily rate of injury than workers employed beyond the conve ntional 30 day orienta tion and training period

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350 (non-new hires). There was a distinct downward trend of the daily inju ry rate as the job tenure of workers increased. Overall job tenure had no aff ect on the severity of the sustained injury. Among all the injuries, a disproportionate num ber of workers were injured while working in carpentry, electrical work, iron and steel wor k, technical repair and maintenance, concrete work, pipe fitting, plumbing, equipment and m achinery operation, and sheet metal work. The occupational work area of the injured worker ha d no affect on the severi ty of the sustained injury. Between 2001 and 2006 there was a distinct downw ard trend in the severity of injuries. There was little difference in distribution of injuries between the months in which the injuries occurred. Slightly fewer injuries occurred dur ing the winter months of November, January, December, and February, than during the warmer months of June, July, and August, when construction work is more intense. Contra ry to Brogmus (2007), no Monday peak was discernable. Injuries occurred on Mondays, Tuesda ys, Wednesdays, Thursdays, and Fridays with rather even distributions. Fewer injuries occurred on Saturdays or Sundays, when less work is performed; however, injuries occurring on the week end tended to be more severe than injuries occurring during several of the business days of the week; namely Tuesdays, Thursdays, and Wednesdays. This may be somewhat attributab le to less supervision by safety management personnel being conducted on the weekends and an increased disconnect from first aid emergency medical services when the fewer workers on the job site. This investigation provides cl ues as to which construction occupational experience levels and occupational work areas generate the highest number of various in juries and occupational diseases and which were at risk for severe injuries (see Table 51). Working as laborers generated the highest number of head, neck, tr unk, lower extremity, and upper extremity injuries

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351 as well as injuries affecting multiple body regions and body systems. This can best be explained by the fact that laborers make up the largest segment of the labor pool. Generally, occupational experience levels had no effect on the seve rity of injury sustained by the worker. Table 51. Most and least severely injured workers by occupational experience level from injuries to the ge neral body regions. Severity Mean General Body Region (n, ) Experience Level (n) % of Injuries to Body Region High Med Low Field supervisors (n = 76) 3.85% 1.32 Most Severe Laborers (n = 1034) 52.33% 1.13 Apprentices (n = 258) 13.06% 1.11 Helpers/assistants (n = 140) 7.09% 1.10 Head (n = 1976, = 1.13) Least Severe Journeymen (n = 185) 9.36% 1.09 Professional (n = 8) 2.65% 1.63 Administrative (n = 7) 2.32% 1.57 Most Severe Laborers (n = 157) 51.99% 1.57 Apprentices (n = 35) 11.59% 1.37 Helpers/assistants (n = 13) 4.31% 1.31 N eck (n = 302, = 1.48) Least Severe Field supervisors (n = 16) 5.30% 1.19 Field supervisors (n = 76) 3.85% 1.32 Administrative (n = 68) 3.44% 1.28 Most Severe Laborers (n = 1034) 52.33% 1.13 Apprentices (n = 258) 13.06% 1.11 Helpers/assistants (n = 140) 7.09% 1.10 Trunk (n = 1976, = 1.13) Least Severe Journeymen (n = 185) 9.36% 1.09 Journeymen (n = 426) 10.29% 1.30 Laborers (n = 2215) 53.52% 1.27 Most Severe Foremen (n = 412) 9.95% 1.26 Professionals (n = 50) 1.21% 1.18 Upper Extremities (n = 4139, = 1.26) Least Severe Administrative (n = 106) 2.56% 1.12 Journeymen (n = 271) 8.64% 1.49 Foremen (n = 334) 10.65% 1.48 Helpers/Assistants (n = 133) 4.24% 1.39 Most Severe Laborers (n = 1768) 56.36% 1.38 Professionals (n = 71) 2.26% 1.35 Lower Extremities (n = 3137, = 1.39) Least Severe Administrative (n = 104) 3.32% 1.20 Journeymen (n = 58) 6.61% 1.79 Apprentices (n = 55) 6.27% 1.58 Professional (n = 30) 3.42% 1.53 Most Severe Laborers (n = 530) 60.43% 1.50 Foremen (n = 75) 8.55% 1.44 Multiple Body Regions or Body Systems (n = 877, = 1.52) Least Severe Administrative (n = 44) 5.02% 1.41 = Severity Mean, High Severity set at 1.35; Low Severity set at 1.10 This investigation provided insight as to which particular body regions and body parts were observed to have frequencies of occurren ce and which tended to be most severe. With

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352 respect to particular body parts, injuries or diseases affecting the heart, spinal cord, pelvis, brain, multiple head, trunk, upper extremities, lower extremities, abdomen, and body systems were the most severe. Injuries to the eyes tended to be the least severe. This de gree of severity likely results from vigilance in the indus try to the fact that eye injuries occurred very frequently and that medical attention is dedicated to even the most minor injuries. Among the general body regions, injuries to the neck, trunk, and multiple body regions and body systems, tended to be the more severe injuries (see Table 52). Even though neck and multiple injuries to bod y regions or body systems are rare, they deserve special attention because of the potential for these injuries to by highl y severe. Similarly, trunk in juries tend to be both frequent and highly severe. Table 52. Most and least se vere injuries by body region. All injuries (n = 45291, = 1.33) Severity Mean Body region % of Injuries High Medium Low Mean Age Neck (n = 964) 2.13%1.48 38.56 Multiple body region or body systems (n = 3388) 7.48%1.47 38.22 Most Severe Trunk (n = 11490) 25.69%1.44 38.30 Lower extremities (n = 9083) 20.05%1.40 38.04 Upper extremities (n = 12939) 28.57% 1.26 37.00 Least Severe Head (n = 7427) 16.40% 1.11 36.68 = Severity Mean, High Severity set at 1.35; Low Severity set at 1.10 As Table 53 shows, injuries to the brain, neck vertebrae, hear t, and discs of the neck were among the most severe of all the injuries. Spec ial attention in terms of both prevention and emergency response, should include consideration of all injuries with an injury mean of 1.50 and above (see Table 53). Crushing injuries to the head and multiple body regions generated the most severe injuries to construction workers (see Table 54). Crushing also generated some of the more sever injuries to the trunk. Rupture injuries were especially se vere to the neck, trunk, upper extremities, lower

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353 extremities, and injuries impacting multiple body regions or body systems. Ruptures are most likely to occur when an excessive force is exerte d on an otherwise healthy disc, knee, elbow, etc. Finally, severance produced highly severe injuri es to the neck, trunk, and upper extremities. The high severity of neck injuries, often resulting fr om ruptures, may be due to the vulnerability of the neck and the lack of personal protective devi ces designed to protect ag ainst neck injuries. Table 53. Most and least se vere injured body part s per body region (also shows mean age). Severity Mean General Body Region (n, Mean Age) Body Part (n) % of Body Region High Med Low Mean Age Brain (n = 6) 0.49% 2.22 38.50 Most Severe Multiple Parts (n = 90) 1.21% 1.64 37.88 Head (n = 7427, = 1.11) Least Severe Eyes (n = 4709) 63.35% 1.05 36.51 Vertebrae (n = 29) 3.00% 2.07 27.75 Most Severe Disc (n = 187) 18.98% 1.87 40.70 N eck (n = 964, = 1.48) Least Severe Soft tissue (n = 630) 0.6579 1.34 38.63 Heart (n = 57) 0.52% 2.19 47.44 Most Severe Pelvis (n = 33) 0.28% 1.82 39.90 Trunk (n = 11490, = 1.44) Least Severe Sacrum & coccyx (n = 28) 0.24% 1.25 36.27 Multiple body parts (n = 259) 1.99% 1.55 43.16 Most Severe Wrist & hand (n = 121) 0.93% 1.52 39.88 Upper Extremities (n = 12939, = 1.26) Least Severe Thumb (n = 1293) 9.99% 1.19 35.51 Multiple parts (n = 116) 1.28% 1.58 41.60 Knee (n = 3074) 33.85% 1.51 39.89 Most Severe Hip (n = 218) 2.39% 1.44 47.60 Lower Extremities (n = 9080, = 1.40) Least Severe Foot (n = 1820) 20.04% 1.27 35.58 Most Severe Multiple body parts (n = 1546) 91.81% 1.60 41.50 Multiple Body Regions of Body Systems (n = 1684, = 1.60) Least Severe Multiple body system(s) (n = 138) 8.19% 1.59 40.77 = Severity Mean, High Severity set at 1.35; Low Severity set at 1.10 Heart attacks (myocardial infarc tions) were the most severe tr unk injury. This is likely to be highly associated with the age and health at tributes of the injured worker. Silicosis, though rarely identified, generated the second most severe trunk injuries Similar to asbestosis, the low frequency of silicosis may be due to the poten tially long onset period for this occupational

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354 disease. Workers may be removed from the c ontributing occupational environment long before that worker is identified with silicosis. Often associated with repeated motions and exposure to constant vibration, carpal tunnel syndrome tended to be highly severe. This may indicate a lack or ergonomic controls in place. These injuries may be common among workers in masonry, concrete, carpentry, and clerical work. Although electric shock was associated with some of the more severe trunk injuries, it was also associated with the least severe injuries to the lower extremities. This may reflect the value of the protective footwear ofte n worn by construction workers. Falling was among the causes of the most se vere injuries among all six general body regions. The most severe neck injuries were caused by falling, as were the most severe upper extremity injuries. This reflects a continued lack of regard for the im portance of fall arrest systems. Falling was among the most frequent causes of injuries to neck, trunk, upper extremities, and especially of injuries to the lower extremities and multiple body regions and body systems injuries. Both the relatively high fr equencies and the associated high severity of injury from falls suggest a delinquency on the pa rt of supervisors to enforce the use of fall protection systems especially at dangerous elev ations.Injuries due to falls from ladders or scaffolding resulted in a high degree of severity. The most severe head injuries and injuries to multiple body regions or body systems were caused by the worker being caught in or between objects. Being caught in between objects was also associated with some of the more severe injuries to the trunk and lower extremities. Being struck by an object was a frequent cause of the more severe injuries to multiple body regions or body systems (MBRBS). Severe MBRBS injuries al so tended to be caused by involvement with a motor vehicle. As a cause of injury, motor vehicl es caused some of the mo re severe injuries to

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355 the head, upper extremities, and lower extremities. Being burned, though infrequent, was associated with the most severe injuries to the trunk. The high severity may be attributed to the fact that second and third degree burns Table 54. Most and least severe nature of injures by body part. Severity Mean General Body Region (n, ) Nature of Injury (n) % of Injuries to Body Region High Med Low Crushing (n = 7) 0.10% 2.86 Mental stress/disorder (n = 7) 0.10% 1.86 Most Severe Hearing loss or impairment (n = 53) 0.77% 1.64 Poisoning NOC (n = 3) 0.04% 1.00 Head (n = 6908, = 1.10) Least Severe Foreign Body (n = 3733) 53.94% 1.03 Rupture (n = 78) 8.85% 2.51 Severance (n = 2) 0.22% 2.50 Most Severe Fracture (n = 22) 2.46% 2.41 N eck (n = 868, = 1.49) Least Severe Burn (n = 20) 2.24% 1.05 Myocardial infarctions (n = 40) 0.37% 2.60 Silicosis (n = 6) 0.06% 2.50 Rupture (n = 156) 1.46% 2.37 Severance (n = 6) 0.06% 2.33 Crushing (n = 13) 0.12% 2.23 Most Severe Electric Shock (n = 14) 0.13% 2.00 Chemical Poisoning (n = 65) 0.61% 1.08 Trunk (n = 10681, = 1.45) Least Severe Foreign Body (n = 5) 0.05% 1.00 Amputation (n = 74) 0.60% 2.24 Rupture (n = 42) 0.34% 2.10 Severance (n = 48) 0.39% 1.88 Carpal tunnel sryndrome (n = 95) 0.77% 1.87 Most Severe Fracture (n = 1095) 8.89% 1.67 Foreign Body (n = 73) 0.59% 1.14 Puncture (n = 986) 8.01% 1.10 Upper extremities (n = 12312, = 1.26) Least Severe Dermatitis (n = 57) 0.46% 1.05 Amputation (n = 10) 0.12% 2.50 Rupture (n = 159) 1.87% 2.37 Most Severe Dislocation (n = 45) 0.53% 2.31 Puncture (n = 853) 10.02% 1.13 Lower extremities (n = 8515, = 1.40) Least Severe Electric Shock (n = 3) 0.04% 1.00 Crushing (n = 11) 0.73% 3.64 Most Severe Rupture (n = 10) 0.66% 2.80 Poisoning NOC (n = 16) 1.06% 1.13 Multiple body regions or body system(s) (n = 1514, = 1.60) Least Severe Dermatitis (n = 50) 3.30% 1.08 = Severity Mean, High Severity set at 1.35; Low Severity set at 1.10

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356 Among all the injuries, there was no apparent a ffect of the workers occupational work area on the severity of the sustained in jury. Based on the scale utilized in Table 51 through Table 55, workers, generally, sustained medium to low severity injuries ( = 1.33, = 0.60). Workers in landscaping sustained the most severe injuries among all the injuries. Workers involved in technical repair and maintenan ce, roofing, flooring, tile, and car peting, working as or with a lineman, driving, hod carrying, painting and pl astering, rigging, operating equipment or machinery, security, inspection, masonry, glazing, carpentry, concrete work, and working as or with a millwright, tended to sustain the most severe injuries. Workers with both high frequency (> 200 injuries) and high severity levels may warrant special attenti on. A grouping of the most severely injured and least severely injured work ers according to their occupational work areas suggests that workers in carpent ry, electrical work, concrete wo rk, and driving sustain the many of the more severe injuries to a ll the body regions (see Table 55). Among all the injuries, general building material s were disproportionately identified as the object or agent contributing to th e injury. Tools, machinery, ladders and scaffolding, changes in surface texture, vehicles, and co-workers, contri buted to high numbers of injuries. The most severe injuries involved vehicles lead containing products, ladder and scaffolds, weighted items, and changes in surface textures. Of these agents, we ighted items, and lead had low frequencies of occurrence. Among the building materials, nails piping, wood, and wire and metal material contributed to the highest number of injuries, but were associated with some of the least severe injuries. Injuries involving power ed hand tools tended to be the most severe injuries involving tools. Injuries from contact with an organism (a nimal, insect, bacteria) rarely occurred, compared with injuries from contact with materials. Animal or insect related injuries also resulted in the least severe injuries. However, among these inju ries, it is important to note that injuries

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357 associated with bacteria were more severe than injuries involving contact with animals or insects. This may suggest an inattention to hygiene and proper first aid for minor injuries on a construction jobsite. Table 55. Most and least severe oc cupational work areas by body region. Severity Mean General Body Region (n, ) Occupational work area (n) % of Injuries to Body Region High Med Low Security (n = 13) 0.22% 1.38 Supervising (n = 76) 1.28% 1.32 Managing (n = 32) 0.54% 1.31 Roofing (n = 21) 0.35% 1.29 Flooring, tile, carpeting (n = 7) 0.12% 1.29 Clerical (n = 36) 0.60% 1.25 Waterproofing (n = 8) 0.13% 1.25 Scaffold erection (n = 18) 0.30% 1.22 Rigging (n = 5) 0.08% 1.20 Driving (n = 45) 0.76% 1.18 Carpentry (n = 924) 15.51% 1.13 Concrete (n = 306) 5.14% 1.11 Most Severe Electrical (n = 740) 12.42% 1.10 Boilermaker (n = 365) 6.13% 1.08 Iron/steel (n = 920) 15.44% 1.08 Welding (n = 279) 4.69% 1.08 Pipe Fitting (n = 476) 7.99% 1.08 Sheet metal (n = 251) 4.21% 1.07 Drywall (n = 50) 0.84% 1.04 Steam fitting (n = 70) 1.18% 1.03 Head (n = 5958, = 1.11) Least Severe Conveyor systems work (n = 13) 0.22% 1.00 Glazing (n = 3) 0.41% 2.00 Driving (n = 14) 1.93% 1.79 Iron/steel (n = 92) 12.69% 1.76 Plumbing (n = 28) 3.86% 1.68 Inspecting (n = 8) 1.10% 1.63 Millwright (n = 13) 1.79% 1.62 Concrete (n = 43) 5.93% 1.53 Carpentry (n = 115) 15.86% 1.52 Most Severe Most Severe Electrical (n = 99) 13.66% 1.41 Boilermaker (n = 19) 2.62% 1.21 Scaffold erection (n = 5) 0.69% 1.20 Supervising (n = 16) 2.21% 1.19 N eck (n = 725, = 1.49) Least Severe Landscaping (n = 3) 0.42% 1.00 Flagging (n = 3) 0.03% 2.00 Acoustic ceiling work (n = 4) 0.05% 2.00 Landscaping (n = 9) 0.10% 1.89 Technical Maintenance & Repair (n = 537) 6.17% 1.57 Painting & Plastering (n = 151) 1.74% 1.53 Masonry (n = 391) 4.49% 1.51 Trunk (n = 8701, = 1.45) Most Severe Boilermaker Work (n = 212) 2.44% 1.51

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358 Table 55. Continued Severity Mean General Body Region (n, ) Occupational work area (n) % of Injuries to Body Region High Med Low Drywall (n = 119) 1.37% 1.50 Equipment/machinery operations (n = 383) 4.40% 1.50 Carpentry (n = 1553) 17.85% 1.48 Iron/steek (n = 1001) 11.50% 1.45 Electrical (n = 1343) 15.44% 1.43 Pipe Fitting (n = 519) 5.97% 1.41 Most Severe Plumbing (n = 321) 3.69% 1.36 Waterproofing (n = 13) 0.15% 1.23 Scaffold erection (n = 26) 0.30% 1.23 Trunk (n = 8701, = 1.45) Least Severe Rigging (n = 8) 0.09% 1.13 Rigging (n = 16) 0.16% 1.44 Surveying (n = 12) 0.12% 1.42 Painting and plastering (n = 126) 1.28% 1.40 Hod carrying (n = 5) 0.05% 1.40 Driving (n = 70) 0.71% 1.40 Millwright work (n = 208) 2.11% 1.38 Roofing (n = 81) 0.82% 1.36 Technical maintenance and repair (n = 593) 6.01% 1.32 Boilermaker Work (n = 223) 2.26% 1.31 Equipment/ machinery operations (n = 262) 2.65% 1.31 Carpentry (n = 2272) 23.01% 1.27 Iron/steel (n = 1115) 11.29% 1.27 Pipefitting (n = 460) 4.66% 1.26 Plumbing (n = 369) 3.74% 1.22 Electrical Work (n = 1658) 16.79% 1.21 Most Severe Sheet Metal Work (n = 427) 4.32% 1.20 Clerical (n = 69) 0.70% 1.10 Conveyor systems work (n = 23) 0.23% 1.09 Filed Engineering (n = 12) 0.12% 1.08 Engineering (n = 20) 0.20% 1.00 Flagging (n = 2) 0.02% 1.00 Upper extremities (n = 9874, = 1.26) Least Severe Landscaping (n = 2) 0.02% 1.00 Conveyor systems work (n = 14) 0.20% 1.79 Flagging (n = 3) 0.04% 1.67 Material handling (n = 10) 0.15% 1.60 Flooring. Tile, Carpeting (n = 30) 0.44% 1.60 Lineman Work (n = 54) 0.79% 1.56 Technical Maintenance & Repair (n = 447) 6.51% 1.55 Rigging (n = 19) 0.28% 1.53 Driving (n = 74) 1.08% 1.47 Painting & Plastering (n = 110) 1.60% 1.45 Lower extremities (n = 6871, = 1.41) Most Severe Glazing (n = 59) 0.86% 1.44

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359 Table 55. Continued. Severity Mean General Body Region (n, ) Occupational work area (n) % of Injuries to Body Region High Med Low Carpentry (n = 1282) 18.66% 1.43 Sheet Metal Work (n = 197) 2.87% 1.43 Roofing (n = 53) 0.77% 1.42 Pipe Fitting (n = 379) 5.52% 1.41 Equipment/Machinery Operations (n = 293) 4.26% 1.41 Millwright work (n = 134) 1.95% 1.40 Drywall (n = 76) 1.11% 1.39 Masonry (n = 237) 3.45% 1.39 Plumbing (n = 248) 3.61% 1.38 Most Severe Electrical Work (n = 1053) 15.33% 1.38 Clerical (n = 64) 0.93% 1.17 HVAC/refrigeration (n = 6) 0.09% 1.17 Field engineering (n = 8) 0.12% 1.13 Surveying (n = 8) 0.12% 1.13 Hod carrying (n = 6) 0.09% 1.00 Lower extremities (n = 6871, = 1.41) Least Severe Acoustic ceiling work (n = 8) 0.12% 1.00 Hod carrying (n = 4) 0.18% 1.75 Roofing (n = 19) 0.83% 1.63 Carpentry (n = 289) 12.65% 1.63 Lineman Work (n = 27) 1.18% 1.59 Engineering (n = 12) 0.53% 1.58 Glazing (n = 12) 0.53% 1.58 Steam fitting (n = 14) 0.61% 1.57 Driving (n = 32) 1.40% 1.56 Equipment/Machinery Operations (n = 103) 4.51% 1.55 Iron/Steel Work (n = 235) 10.28% 1.55 Most Severe Technical Maintenance and Repair (n = 151) 6.61% 1.54 Plumbing (n = 109) 4.77% 1.28 Security (n = 13) 0.57% 1.23 HVAC/refrigeration (n = 10) 0.44% 1.20 Drywall (n = 83) 3.63% 1.17 Multiple Body Regions and Body Systems (n = 2285, = 1.45) Least Severe Flagging (n = 6) 0.26% 1.17 = Severity Mean, High Severity set at 1.35; Low Severity set at 1.10

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360 CHAPTER 6 RECOMMENDATIONS Because of the constantly changing conditions at construction jobsites, the construction industry is particularly hazardous. Dangers incl ude falls, being struck by falling or swinging objects, and collapse of trenches, temporary st ructures, and building components. One major component of any injury-control program must be worker traini ng and education. Other elements should include the establishment of company policie s for injury prevention, incorporating worker safety considerations into the design and planni ng of buildings and jobsite throughout the entire life cycle of a built structure, maintaining accurate records of causes of injury, and placing workers in jobs suitable to their physical abilities. Recommendations for Industry The prevention of head and neck injuries requires the control of the transfer of destructive energy to reduce jobsite hazards: At the source of energy (e.g., securing c oncrete masonry units (CMU) so they dont fall on workers). At the point of transmission of energy (e.g., building overhead barriers so a falling CMU does not strike workers). At the worker level (e.g., requiri ng workers to wear hard hats). Hearing impairment or loss, though not comm on, can be easily prevented. Effective hearing conservation programs should identify the following ar eas where noise levels are hazardous: employ administrative and engineering c ontrols over noise levels; provide effective worker education and training; pr ovide and enforce the use of h earing protectors (inserts, muffs, canal caps); and establish peri odic audiometric testing to monitor the effectiveness of the program. Workers frequently do not realize th e damaging effects of loud noise, and simply accept it as part of the job. For this reason training programs s hould include the education of

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361 workers about the delicate nature of the hearing mechanism, and the importance of the protecting this mechanism with hearing protection. The prevention of injuries at the source invol ves initial safe design of sites, plants, equipment and construction processes. Compan ies should also implement formal injury prevention programs. The notion that workplace inju ries are primarily caused by unsafe behavior on the part of workers may inhibit the construction company and owners from exercising safe design. At the construction sites, falls can be prevented by the pr oper use of ladders, scaffolding. Ladders and scaffolding should be strong enough, high enough, as well as promote the adequate blockage of openings. Safe design at the planning stage can prevent the collapse of temporary structures (e.g., scaffolding) and building components. Shoring tr enches and sloping trench sides will prevent collapse. Designing construction sites so that workers do not need to enter areas where there are flying objects will avoid injury as will usi ng heavy equipment fitted with cages around the drivers seat to protect the worker from falling and from sw inging objects. Cranes with swinging loads can be sited away from work areas. Planning and scheduling can minimize the presence of other workers while cranes are in operation. The prevention of motor vehicle accidents depe nds highly on the proper training of drivers, provision of adequate braking systems on trucks and earth moving equipment, and effective trafficking schedules to minimize the presence of ot her workers in the vicinity of motor vehicle. Construction workers must depend on protec tive headgear for the immediate protection from injury. Hard hats are not foolproof. De fects and improper maintenance can lead to unexpected hard hat failures. Workers may refuse to wear hard hats for various reasons. Workers

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362 must be required to wear hard ha ts. Neck restraining devices, such as neck rolls used in football, may help reduce the likelihood of severe ruptures The design of the workplace and of equipment may help decrease the rate of n eck strains due to posture. The wo rk method may also be altered to reduce the likelihood and severity of strain rela ted injuries to the neck (e.g., frequent rest periods to allow the workers muscles to more completely relax). Eye injuries were among the most common yet one of the least severe head injuries in my study. The high frequency of eye injury suggests reluctance on the worker to use recommended eye protection devices. The low severity reflec ts the importance of preserving maximum utility of the eyes during tasks, thus warranting imme diate and focused attention even for the most minor of injuries. Workers should always conduc t an eye hazard evaluation on the jobsite. As much as is possible, eye hazards should be re moved by using engineering controls. Construction companies should always have the appropriate safety eye protection at the jobsite. The prevention and minimization of the severity of upper and lower extremity injuries to construction workers should involve education and training, the use of appropriate personal protective equipment, ergonomic programs to fit the job to the worker, and tool design. Tools can be designed to minimize the amount of work required to operate them; this includes the angle and size of the handle, the weight of the t ool, and the use of tool balancers or slings for heavy tools. Also important is a monitoring system to ensure that safety procedures are in use (e.g., many workers who sustained hand injuries may have removed or altered safety devices in order to improve the presumed efficiency of their tools). The thrust of preventing hand and foot injuri es should be on protec tive clothing. Protective footwear and gloves should be designed to pr otect the worker from hazards specific to the worker. No less important is the attention to fl oor surfaces, to prevent slips, which are often

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363 associated with shoulder, knee, ankle, hand, and wrist injuries. Surface conditions can be improved through effective design and maintenan ce. Most protective shoes for construction workers should be able to protect against im pact, compression, heat, static electricity, high voltage and slippery surfaces. To be effective, safety gloves and shoes appropriate for the job must be worn. This means that their use must be required and that workers be educated in their proper use and upkeep. The steel toe cap is a critical protective device for many construction workers who are frequently at risk for injuries due to object s being dropped on the foot. Additional protection for the foot and ankle could be provi ded by the inclusion of metatarsal shields, used to protect the top surface of the foot, specially designed gaiters (foot and/or leg coverings), and high-top boots. Recommendations for Insurance Carriers Insurance companies who provide workers compensation to construction firms can do much to assist construction companies in identifying, evaluating, co ntrolling and removing safety and health hazards during the entire c onstruction process. The insurance provider can consult with construction companies on various safety activities. They can assist small construction firms by providing training that addr esses key areas of poten tial injury, including fall protection, welding, trenchi ng and shoring, Cooperative efforts between contractors, owners, designers, and insurance providers c ould work toward insuring that: Safety, health and welfare provisions should be included as mandatory in contract documents, so as to remove these considerations from competition. All contractors, subcontractors, sub-subc ontractors, etc. should ebe rquireed to include safety and welfare items in their estimated costs. All management and supervisory staff should demonstrate competence in occupational health and safety. Insurance pr oviders could offer incentives or even require that certifi cation be provided.

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364 All workers should have to demonstrab le skill levels, incorporating safety. Safety compliance should be monitored and recorded accurately and consistently. Ensure that recording of injury occu rrences be detailed and that as much preexisting information regarding the tas k, environment, and worker be provided. Insurance companies could assist independent researchers who use workers compensation data by including information regarding the ethn icity of workers, and preexisting health and medical conditions (blood pressure, weight, height, prior in juries and illnesses, etc.). They could also assist the research by ensuring quality reco rding of injury informa tion; this would include consistent and accurate coding of data. The appa rent ease and economy of using pre-collected data cannot eliminate the need for critical selection, examinati on, and analysis of these data. Once in hand, the completeness a nd coding of the data should be examined in detail before attempting to test hypotheses. Recommendations for Future Research Future research could examine in greater detail the impact of age, e xperience level, and job tenure on the frequency and severity of injuries in construction. Th e effect of preexisting ethnic, social, health and medical conditions should be ex amined in conjunction with age, occupational, and environmental variables on the frequency and se verity of injuries to construction workers. Research could also identify those aspects and types of construction work where the effort devoted to risk management is disproportionate ly low with respect to the potential for multiinjury consequences. Additionally, injuries that show the potential to be quite severe, even though there likelihood of occurrence may be qui te low, deserve special attention. Having identified these aspects, recommendations c ould be made in whatever action seems most appropriate (e.g. through regulation, guidance, education, detect ion, and emergency response).

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365 Future research could focus on specific tr ades, tasks, and phases of construction. Biomechanical profiles could be constructed for tr ades relative to their specific tasks. Research of the dynamic characteristic of particular pha ses of construction could provide a clearer understanding of the hazards associated with specific activities on a j obsite (e.g., limitations, worker density). This would include the examination of the impact of overtime on the frequency and severity of injuries. Such research would en tail the generation of inju ry profiles of workers relative to the specific type of project, and to the per centage of project completion.

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366 APPENDIX A DEFINITIONS FOR NATURE OF INJURY CODES Table A1. Specific Injuries Code# Label Description 101 No physical injury Specific injury not li sted; or nature stated as no injury. 102 Amputation Loss of limb, part of organ; bone loss must be involved to consider a finger or toe injury an amputation. 103 Angina pectoris Condition associated with heart disease. 104 Burn Resulting from contact with hot or cold temperature extremes; tissue damage resulting from corrosive action of chemical compounds (acids, alkalis), fumes, etc. Includes skin burns from anhydrous ammonia, and dry ice, cement, friction, lightning, and sunburns. Does not include electrical shock or heat stroke. 107 Concussion Injury resulting from impact with an object; ma y include loss of consciousness. 110 Contusion Bruise; skin is intact, broken blood vessels (includes broken blood vessels in the eye). 113 Crushing Skin intact, broken blood vessels. 116 Dislocation Temporary displacement of a bone from its normal position in a joint. Includes herniated or r uptured disc; pinched nerve in back, slipped disc, and sciatica. 119 Electric shock Injury due to contact with electrical cu rrent; electrocution, struck by lightning. 122 Enucleation Removal of an entire mass without rupture, i.e. eye. 125 Foreign body Slivers, cinders, dirt or ot her small objects that lodge in the eyes, ears, nose, skin or internally. Does not include needle stick. 128 Fracture Sudden breaking of a bone. 130 Freezing Limb or part of body becoming stiff, rigid and inflexible due to exposure to cold. Includes hypothermia and frostbite. 131 Hearing loss or impairment Loss of hearing; traumatic only; also includes deterioration of hearing subsequent to specific incident.

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367 Table A1. Continued. Code# Label Description 132 Heat prostration Exhaustion resulting from excessive exposure to heat, heat stroke. 134 Hernia Protrusion, projection, or rupt ure of an organ or a part of an organ through the wall of the cavity that normally contains it. Includes inguinal and non-inguinal hernia. Does not include herniated disc. 136 Infection Condition in which part of the body is invaded by a pathogenic agent (microorganism or virus) Includes boils, carbuncles, cellulitis, abscesses, lymphadeni tis, impetigo, pyodermia, etc. 137 Inflammation Tissue reaction due to inju ry (internal or external) of joints, tendons, or muscles. Includes tendonitis, arthritis, dermatitis, bursitis, etc. Does not incl ude Occupational Diseases or injuries that developed over a period of time. 140 Laceration Cut or tear of the skin; an open or superficial wound. 141 Myocardial infarction Heart Attack. 142 Poisoning General Not an overdose or Cumulative Injury; specific incident of poisoning. 143 Puncture Hole or wound made by a sharp pointed instrument. Includes injection of paint, grease, wate r or other fluid under pressure. Includes needle stick. 146 Rupture Breaking of internal tissu e or organ, e.g., rupture of appendix. 147 Severance Loss of soft tissue, bone re mains intact. May involve fingertips, earlobes, etc. 149 Sprain Trauma to joint, may include torn ligaments; torn, ruptured muscles; ruptured knee cartilage (no dislocation); and spinal subluxation. 152 Strain Trauma to muscle from vi olent contraction, strong effort, or excessive use. 153 Syncope Fainting; loss of consciousness due to inadequate blood flow to the brain. 154 Asphyxiation Insufficient intake of ox ygen may or may not result in death. Includes drowning, strangulation, suffocation, etc.

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368 Table A2. Occupational diseas es or cumulative injuries Code # Label Description 155 Vascular loss Loss of circulation. 158 Vision loss Loss of eyesight; traumatic only. 159 All other specific injuries, NOC Specific injury Not Otherwise Classified. 260 Dust disease NOC Condition of respiratory tract due to inhalation of dust particles (Dust diseases Not Otherwise Classified). 261 Asbestosis Lung disease resulting from inhalation of asbestos particles. 262 Black Lung Chronic lung disease or pneumoconiosis, often found in coal miners. 263 Byssinosis Pneumoconiosis of cotton, flax and hemp workers. 264 Silicosis Pneumoconiosis resulting fr om inhalation of silica (quartz dust). 265 Respiratory disorder Respiraton ailments resulting from exposure to gases, fumes, chemicals, etc. 266 Poisoning chemical Any chemical substance take n into the body by ingestion, inhalation, or absorption that interferes with normal physiological functions. Include s pesticides, insecticides, cleaning agents, drug poisoning, etc. 267 Poisoning metal Any metallic substa nce taken into the body by ingestion, inhalation or absorption that inte rferes with normal physiological functions. Includes alkalies, me rcury, lead, arsenic compounds, etc. 268 Dermatitis Inflammation of skin evidenced by itching, redness, boils, or lesions. Generally resulting from direct contact with drugs, agents, plants, woods, liquids, etc. Does not include tissue damage resulting from corrosive action of chemicals, burns from contact with hot substances, or effects or radiation or temperature extremes. 269 Mental disorder Acute anxiety, neurosis (nontoxic or toxic), and shock (when not incurred by physical trauma). Do es not include mental stress.

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369 Table A2.Continued. Code # Label Description 270 Radiation Radiation syndrome; illness resulting from exposure of body tissue to ionizing radiations from radioactive substances. 271 All Other occupational disease NOC Applies to occupational diseases and cumulative injuries occurring over a period of time as a result of repetitive motion, which may include sitting, typing, folding, etc. And are not otherwise classified. Includes va ricose veins and bone spurs. Does not apply to specific injuries. 272 Loss of hearing Loss of hearing due to cumulative circumstances. 273 Contagious disease An Ailment resulting fr om contact with an infectious organism. May include TB, conjunctivitis, meningitis, chicken pox, anthrax, hepatitis, etc. 274 Cancer Malignant or beni gn tumor; includes leukemia. 375 AIDS An ailment resulting from cont act with an infectious individual. Acquired Immune Deficiency Syndrome. 376 VDT-related disease Video Display Terminal-related; may affect eyes, hands, back, neck, etc. 377 Mental stress Psychological disruptio n (fear, anxiety, crisis, depression). 378 Carpal tunnel sryndrome Soreness, tenderness and weakness of the muscles of the thumb caused by pressure on the median nerve at the point where it goes through the carpal tunnel of the wrist. May involve damage to the hands, wrists, forearms, elbows, and shoulders. May also include ganglion cysts in the wrist area. Table A3. Multiple Injuries Code# Label Description 490 Multiple physical injuries only Involves more than one nature of injury: does not include psychological disorders. 491 Multiple injuries (including phys & psych) Involves multiple injuries where at least one is of the psychological nature.

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370 APPRENDIX B DEFINITIONS FOR PA RT OF BODY CODES Table B1. Head Code# Label Description 10 Multiple head injury Any combination of brain, scalp, skull with or without ears, eyes, nose, mouth, teeth, face, or neck. Includes head not otherwise classified. 11 Skull Cranial bones 12 Brain Includes brain concussion; brain damage. 13 Ear(s) Includes inner and outer ear, ea rdrum, hearing and loss of hearing. 14 Eye(s) Includes optic nerves, vision and loss of vision. 15 Nose Includes nasal passages, sinus and sense of smell. 16 Teeth Does not include gums or false teeth. 17 Mouth Includes tongue, gums, lips, th roat, and sense of taste. Includes jaw and chin. Does not include teeth. 18 Soft tissue Pertaining to cuts and brui ses; includes cheek, eyebrow, forehead, and scalp. 19 Facial bones Pertaining to fractures of facial bones, not the skull. Table B2. Neck Code# Label Description 20 Multiple injury Any combination of vertebr ae, disc, spinal cord or soft tissue in neck. Also, neck not otherwise classified. 21 Vertebrae Spinal column bone in the neck includes the first seven bones of the spinal column (cervical vertebrae). 22 Disc Spinal column cartilage in the neck. 23 Spinal cord Nerve tissue in the neck. 24 Larynx voice box, includes loss of voice, vocal chords. 25 Soft tissue Soft tissue in the neck ar ea (internal) other than the larynx or trachea.

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371 Table B2. Continued. Code# Label Description 26 Trachea Cartilage tube leading from the larynx to the bronchial tubes. Table B3. Upper extremities. Code# Label Description 30 Multiple upper extremities Any combination of arm, elbow or fingers. Also arm not otherwise classified. Does not in clude a specific wrist & hand combination. 31 Upper arm(s) Arm between elbow and shoulder. Does not include shoulder, clavicle (collarbone), scapula (s houlder blade) or rotator cuff. 32 Elbow(s) Joint of the upper arm and the forearm. 33 Lower arm(s) Portion of the arm between the elbow and the wrist. 34 Wrist Joint of the hand and the forearm. 35 Hand(s) Does not include the wrist or fingers. Includes metacarpal bones, top of hand and the palm. Use for any injury described as between the fingers. 36 Finger(s) Includes fingernail(s). 37 Thumb(s) Includes thumbnail(s) 39 Wrist(s) and hand(s) Specific injury or occupational di sease where both the wrist(s) and hand(s) are involved. Table B4. Trunk Code# Label Description 38 Shoulder(s) Junction of clavicle and scapula where arm meets trunk; includes rotator cuff, collarbone and shoulder blade. 40 Multiple trunk Any combination of hip, abdomen, chest, back, and shoulder. Also, trunk not otherwise cl assified. Includes side. 41 Upper back Thoracic area, includes vertebrae and muscle pull or ligament strain. 42 Lower back Lumbar and lumbo-sacral ar eas, includes muscle pull or ligament strain; use when description does not differentiate between upper and lower back, i.e., back. Does not include lumbar or sacral vertebrae.

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372 Table B4. Continued. Code# Label Description 43 Disc Spinal column cartilage in the back.. 44 Chest Includes ribs, sternum (breastbone), soft tissue and chest pain; does not include heart or lungs. 45 Sacrum and coccyx Posterior boundary of pelvis and base of vertebral column (tailbone). 46 Pelvis Bone structure formed by innominate (nameless) bones and the ligament uniting them 47 Spinal chord Nerve tissue in the back. 48 Internal organs Applies when the func tioning of an entire body system has been affected without specific injury to any other part, as in the case of poisoning, corrosive action affecting internal organs, insect bites resulting in an allergic reaction, damage to nerve centers, stress, etc. 49 Heart Heart attack (myocardial infa rction) or congestive heart failure. 60 Lungs Specific injury or condi tion affecting the lungs only. 61 Abdomen including groin Specific injury to specific parts only; includes stomach, lower esophagus, groin, small or large in testines, liver, gall bladder, spleen, pancreas, kidneys, and appendix. Do not use if functioning of entire body system is affected (internal organs). 62 Buttocks External posterior of pelvis & hip area. 63 Lumbar and/or sacral vertebrae Vertebrae of the lumbar and/or sacral areas; also includes vertebrae in trunk area that are not otherwise classified. Table B5. Lower extremities Code# Label Description 50 Multiple lower extremities Any combination of leg, hip, thi gh, knee, ankle, foot, and toe. Also, leg not otherwise classified. 51 Hip(s) Upper part of thigh formed by femur and innominate (nameless) bones. The region on each side of pelvis; does not include buttocks or side. 52 Upper leg(s) Part of leg between kne e and hip; part of thigh below hip. 53 Knee(s) Includes the patella (kneecap) and supporting ligaments.

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373 Table B5. Continued Code# Label Description 54 Lower leg(s) Part of leg above the ankle, below the knee. 55 Ankle(s) Joint betwee n the leg and the foot. 56 Foot/feet Part of the foot/feet that does not include the ankle or toes. Includes the heel. Used for any injury described as between the toes. 57 Toe(s) Toes and toenail(s) but excludes the great toe(s). 58 Great toe Large toe(s) Table B6. Multiple body parts Code# Label Description 64 Artificial appliance Damage to a device th at is used to augment performance of a natural function, e.g., hearing aids, eyeglasses, dentures, artificial limbs, etc. 65 Unclassified or known. Applies when specific part of body is not identified 66 No physical injury Applies when specific part of body is stated as no injury. 90 Multiple body parts Applies when more than one major body part has been affected, such as an arm and a leg. 91 Body systems and multiple body systems Applies when one or more body systems have been affected, i.e. Circulatory and/or respirat ory systems. Includes aids, paralysis, electrocution, electri cal shock, forms of infectious or parasitic illnesses, such as scabies, ticks, chicken pox, shingles, etc. Also in cludes fatality, noc.

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374 APPENDIX C DEFINITIONS OF CAUSE OF INJURY CODES Table C1. Burn or scald Code # Label Description 101 Acid chemicals Includes hydrochloric acid, sulfuric aci d, battery acid, and methanol and antifreeze. 102 Contact with hot objects or substances: In cases where contact with a specific hot object occurs; does not include steam or hot fluids. 103 Temperature extremes Applies to non-impact injuries re sulting in a burn due to hot or cold temperature extremes; includes freezing or frostbite. 104 Fire or flame Burns to the skin as a result of exposure to fire not caused by an explosion. 105 Steam or hot fluids: Contact with steam or hot fluids. 106 Dust, gases, fumes, or vapors: Includes inhalation of ca rbon dioxide, carbon monoxide, propane, methane, silica (quartz) and asbestos dust. Includes smoke inhalation. 107 Welding operations Includes welders flash, burns to skin or eyes as a result of exposure to intense light from welding. 8 Radiation Includes effects of i onizing radiation found in x-rays, microwaves, nuclear reactor wast e, and radiating substances and equipment. Also includes non-ionizing radiation such as sunburn. 109 Contact with, noc: Burned or scalded by cont act with heat or cold but exact injury is not discernable on first report of injury or is not otherwise classified in any other code ; may include injury due to cleaning agents fertilizers, etc. 111 Contact with cold objects or substances In cases where contact with a sp ecific cold object or substance occur; does not include freezing or frostbite. 114 abnormal air pressure: Burn or scald injury caused by exposure to abnormal air pressure. 184 Electrical current Burn or scald injury from electric shock, electrocution, lightning, etc.

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375 Table C2. Caught in or between Code # Label Description 210 Machine or machinery: Running or meshing objects, a moving and a stationary object, two or more moving objects (not necessarily a machine). 212 Object handled: May include medical hos pital bed & parts, 30. Slipped; did not fall. 213 Caught in, under or between, noc Not otherwise classified; caugh t between codes do not apply when the source of injury is a flying or falling object. 220 Collapsing materials Slides of ear th, collapse of buildings, etc.) Table C3. Cut, puncture, scrape Code # Label Description 315 Broken glass Cut or puncture caused by the handling of broken glass. 316 Hand tool, utensil; not powered: Includes injury caused by needle, pencil, knife, hammer, saw, axe, screwdriver, etc. 317 Object being, lifted or handled Includes being cut, punctured or scraped by a person or object being lifted or handled; not including powered hand tools, appliances, utensils or broken glass. 318 Powered hand tool; appliance Includes injury caused by drill, grinder, sander, iron, blender, welding tools, etc. 319 Cut, puncture, scrape, noc Not otherwise classified; include s injury by power-actuated tools such as a gun. Table C4. Fall or slip Code # Label Description 425 From a different level Fall to a lower level from a higher level; includes collapsing chairs, falling from piled materials, etc. 426 From ladder or scaffolding Fall to a lower level from ladder / scaffolding. 427 From liquid or grease spills: Fall to the same or a lower level as a result of slipping in a liquid or grease spill. 428 Into openings Fall or slip into opening i.e. Mining shafts, holes in the floor, elevator shafts.

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376 Table C4. Continued. Code # Label Description 429 On same level Fall to the same level or walkway; does not include falling as a result of liquid or grease spills. 431 Fall, slip, trip, noc Not otherwise classi fied; includes tripping over object, slipping on organic material, slip but fall not specified. 432 On ice or snow Fall to same or lower le vel as a result of s lipping on ice or snow, wheelchair, clothespin, vise etc. 433 On stairs Fall or slip injury caused by falling down stairs, missed step while going down, falling up the stairs, etc. Table C5. Motor vehicle Code # Label Description 540 Crash of water vehicle Collision of water vehicle with a fixed object or another water vehicle. 541 Crash of rail vehicle Collision of rail ve hicle with a fixed object or another rail vehicle. 545 collision with another vehicle Collision occurring when both vehicles are in motion; does not apply to water or rail vehicles. 546 Collision with a fixed object Collision occurring when one vehicle or another object are stationary; does not apply to water or rail vehicles. 547 Crash of airplane Collision of airplane with a fixed object or another airplane. 548 Vehicle upset Rollover of vehicle. 550 Motor vehicle, noc Not otherwise classifi ed; injuries due to sudden stop or start. Includes being thrown against inte rior parts of the vehicle and vehicle contents being struck by a water, rail or motor vehicle. Table C6.. Strain Code # Label Description 652 Continual noise Injury to ears or hear ing due to constant or repetitive noise, cumulative. 653 Twisting Free bodily motion which impos es stress or strain on some part of body; assumption of un-natural position; also involuntary motions induced by sudden noise, fright or efforts to recover from slips or loss of balance.

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377 Table C6. Continued. Code # Label Description 654 Jumping Injury occurs as a result of jumping or leaping; does not include injuries as a result of landing on the ground. 655 Holding or carrying Applies to objects or people. Includes restraining a person. Does not include struck by a person. 656 Lifting Applies to objects or people. 657 Pushing or pulling Applies to objects or people. 658 Reaching Injury resulting from reaching up, down, out, or across to retrieve an object or a person. 659 Using yool or machine Sudden overexertion while using a tool or a machine. 660 Strain or injury by, noc Injury resulting in a strain where cause is unknown or not otherwise classified. 661 Wielding or throwing Excessive physical effort resulting in overexertion may result from attempts to resist a force applied by an object being handled. 697 Repetitive motion Cumulative injury or condition caused by continual, repeated motions; strain by excessive use. Table C7. Striking against or stepping on Code # Label Description 765 Moving parts of machine None 766 Object being lifted or handled None 767 Sanding, scraping, cleaning May include scratches or abrasions caused by sanding, scraping, and cleaning operations. 768 Stationary object None 769 Stepping on sharp object None 770 Striking against or stepping on, noc Injuries caused by striking agai nst or stepping on something that is not otherwise classified.

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378 Table C8. Struck by Code # Label Description 874 Fellow worker, patient Struck by co-worker, either on pur pose or accident ally; includes being struck by a patient while lifting or moving them. 875 Falling or flying object 876 Hand tool or machine in use 877 Motor vehicle Applies when a person is struck by a motor vehicle, including rail vehicles, water ve hicles and airplanes. 878 Moving parts of machine 879 Object being lifted of handled 880 Object handled by others Includes another person dropping object on injured persons body part. 881 Struck by noc Injury caused by being struck or injured by something that is not otherwise classified. 885 Animal or insect Includes bite or sting from a living organism. Includes an allergic reaction to the pr esence of a dog, cat, etc. 886 Explosion or flare back Rapid expansion, outbreak, bur sting or upheaval. Includes explosion of cars, bottles, aerosol cans, buildings, etc. Does not include electrical short circuits (blown fuses). flare back involves superheated air and combustible gases at temperatures just below the ig nition temperature. Flare back may have same effects as welders flash. Table C9. Rubbed or abraded by Code 3 Label Description 994 Repetitive motion Caused by repeated rubb ing or abrading; applies to non-impact cases in which the injury was produced by pressure, vibration or friction between the person and the source of injury. 995 Rubbed or abraded, noc Caused by a specific incident of rubbing or abrading that is not otherwise classified; incl udes foreign body in ears.

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379 Table C10. Miscellaneous causes Code # Label Description 1082 Absorption, ingestion, or inhalation, noc Applies only to non-impact cases in which the injury resulted from inhalation, absorption (ski n contact), or ingestion of harmful substances not otherwise classified. 1087 Foreign matter in eye(s) None 1089 Person in act of crime Specific injury caused as a resu lt of physical contact between injured person and another person in the act of committing a crime; does not include stress or psychological trauma that develops secondary to physical injuries. 1090 Other than physical cause of injury Stress, shock, or psychological tr auma that develops in relation to a specific incident or cu mulative exposure to conditions. 1098 Cumulative, noc Involves cases in whic h the cause of injury occurred over a period of time; any condition incr easing in severity over time, not otherwise classified. 1099 Other-miscellaneous, noc Any injury or condition that does not apply or is not otherwise classified in other categories ; includes specific injury to ears/hearing, etc.

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380 APPENDIX D AGENT OF INJURY CODES AND DEFINITIONS Table D1. Agent of injury Code # Label/description 101 Building exposure carbon monoxide 102 Building exposure com ponents/sick building 103 Building exposure construction products 104 Building exposure other fumes non-products 105 Building exposure windows/doors 201 Chemical acid 202 Chemical fumes 203 Chemical fumes hard metals, including welding 204 Chemical fumes pesticides, herbicides, fertilizers 205 Chemical fumes coa tings, paint (not lead) 206 Chemical smoke 301 Furniture bed 302 Furniture commode 303 Furniture display items 304 Furniture fixtures, furnishings 401 Ladder or scaffolding 501 Lead 502 Lead other 503 Lead paint premises 504 Lead paint products 601 Machinery belts, pulleys, gears, shafts 602 Machinery conveyors 603 Machinery deli slice 604 Machinery furnace or heating equipment 605 Machinery hoisting apparatus 606 Machinery maintenance equipment 607 Machinery metal working 608 Machinery noc 609 Machinery pumps 610 Machinery scanner, scanning equipment 611 Machinery weaving 612 Machinery wood working 613 Machinery wrap dispenser 614 Machinery turnstile 615 Machinery electrical apparatus 701 Manhole 801 Material asbestos 802 Material asbestos contractor 803 Material asbestos premises 804 Material automotive parts 805 Material boxes, barrels, containers, packages

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381 Table D1. Continued. Code # Label/description 807 Material china or glass 808 Material coal and petroleum product(s) 809 Material door or door part 810 Material door or drawer 811 Material fence 812 Material fence gate or gate arm 813 Material garbage cans, bags 814 Material gravel 815 Material luggage 816 Material nail 817 Material not mold, mildew, window, door 818 Material other foreign matter not listed 819 Material plastic 820 Material plumbing 821 Material pulp or paper 822 Material rock or stone (minerals) 823 Material scrap materials not listed 824 Material shoes, clothing, apparel 825 Material splinter 826 Material windows, doors 827 Material wire or metal 828 Material wood 901 Organism animal animal or insect converted claims only 902 Organism animal animal part 903 Organism animal insect part 904 Organism bacteria 905 Organism plant 1001 Person administrator 1002 Person medical personnel 1003 Person employee or coworker 1004 Person maintenance personnel 1005 Person nurse lpn or lvn 1006 Person nurse practitioner 1007 Person occupational therapist 1008 Person operating room technical repair and maintenance 1009 Person orderly 1010 Person other patient 1011 Person other person, not listed 1012 Person social worker 1013 Person terrorist attack 9/11 1101 Pothole(s) 1201 Power lines or poles 1301 Sharp object not listed 1401 Spills leakage tank or vessel

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382 Table D1. Continued. Code # Label/description 1402 Spills liquid, food or grease 1501 Surface texture change in 1502 Surface texture wet floor, cleaning or wax 1601 Tool hand non power carton cutter 1602 Tool hand non power knife 1603 Tool hand non power 1604 Tool hand power 1605 Tool power band saw 1606 Tool 1701 Hose 1801 Pipe 1901 Vehicle 1902 Vehicle cart, wagon, bicycle 1903 Vehicle golf cart 1904 Vehicle machinery mobile equipment 2001 Weather conditions ice, rain, snow 3001 Weighted item up to 25 lbs. 3002 Weighted item 26 to 50 lbs. 3003 Weighted item 51 to 75 lbs. 3004 Weighted item 76 to 100 lbs. 3005 Weighted item 101 to 150 lbs. 3006 Weighted item more than 150 lbs. 3007 Weighted item 3008 Weighted item 99999 Missing Table D2. General agent of injury. Code # Label 100 Building exposure 200 Chemical 300 Furniture 400 Ladder/scaffold 500 Lead 600 Machinery 700 Manhole 800 Material 900 Organism 1000 Person 1100 Pothole(s) 1200 Power lines or poles 1300 Sharp object 1400 Spills 1500 Change in surface texture 1600 Tool(s)

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383 Table D2. Continued. 1700 Hose 1800 Pipe 1900 Vehicle 2000 Weather conditions 3000 Weighted item

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384 APPENDIX E STANDARD INDUSTRIAL CL ASSIFICATION (SIC) C ODES AND DEFINITIONS Table E1. Standard industrial classification (SIC) codes. Code Label Description 1521 General contractors single family houses The category covers general contractors primarily engaged in construction activities (including new work, additions, alterations, remodeling, and repair) of single-family houses. 1522 General contractors residential buildings, other than single-family houses This industry consists of general contractors primarily engaged in the construction of residentia l buildings other than single family homes. This type of construction includes new work, additions, alterations, remodeling, and repair of such establishments as apartment buildings, dormitories, and hotels and motels. 1541 General contractors industrial buildings and warehouses This category covers gene ral contractors primarily engaged in the construction, alteration, remodeling, repair, and renovation of industrial buildings and warehouses, including aluminum plants, automobile assembly plants, food processing plants, pharmaceutical manufacturing plants, and commercial warehouses. General contractors working on nonresidential buildings other than industrial buildings and ware houses are classified in SIC 1542: general contractorsnonresidential buildings, other than industrial buildings and warehouses. 1542 General contractors nonresidential buildings, other than industrial buildings and warehouses This category covers gene ral contractors primarily engaged in the construction, alteration, remodeling, repair, and renovation of nonresidential buildings, other than industrial buildings and warehouses. Included are nonresiden tial buildings of commercial, institutional, religious, or recreational nature, such as office buildings, churches and synagogues, hospitals, museums and schools, restaurants and shopping centers, and stadiums. 1543 General contractor noc This group includes general contractors and operative builders primarily engaged in the construction of residential, farm, industrial, commercial, or other buildings, not elsewhere classified.

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385 Table E1. Continued. Code Label Description 1611 Highway and street construction This industry covers ge neral and special trade contractors primarily engage d in the construction of roads, streets, alleys, public sidewalks, guardrails, parkways, and airports. 1622 Bridge, tunnel, and elevated highway construction. This category covers gene ral contractors primarily engaged in the constructi on of bridges; viaducts; elevated highways; and highway, pedestrian, and railway tunnels. General contractors engaged in subway construction are classified in sic 1629: heavy construction, not elsewhere classified. 1623 Water, sewer, and utility lines This industry covers ge neral and special trade contractors primarily engage d in the construction of water and sewer mains, pipelines, and communications and power lines. 1629 Heavy construction noc This classification covers general and special trade contractors primarily engage d in the construction of heavy projects, not el sewhere classified. 1711 Plumbing, heating, and air conditioning This industry classification covers special trade contractors primarily enga ged in plumbing, heating, air conditioning, and similar work. Sheet metal work performed by plumbing, heating, and air conditioning contractors in conjunction with the installation of plum bing, heating, and air conditioning equipment is in cluded here, but roofing and sheet metal work contractors are classified in sic 1761: roofing, siding, and sheet metal work. 1721 Painting and paper hanging This classification includes special trade contractors primarily engaged in painting and paper hanging. Special trade contractors pr imarily engaged in roof painting are classified in sic 1761: roofing, siding, and sheet metal work. 1731 Electrical work This category c overs special trade contractors primarily engaged in electr ical work at the site. 1741 Masonry, stone setting, and other stone work This category covers sp ecial trade contractors primarily engaged in masonry work, stone setting, and other stone work.

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386 Table E1. Continued. Code Label Description 1742 Plastering, drywall, acoustical, and insulation This category is comprised of special trade contractors primarily engaged in applying plain or ornamental plaster, or in the installation of drywall and insulation. Activities include taping and finishing drywall, applying solar-reflecting insulation film, installing lathing, and constructing ceilings. 1743 Terrazzo, tile, marble, and mosaic work This category is comprised of special trade contractors primarily engaged in sett ing and installing ceramic tile, marble, and mosaic, and in mixing marble particles and cement to make terrazzo. 1751 Carpentry work This category in cludes special trade contractors primarily engaged in carpentry work. Establishments primarily engaged in building and installing cabinets at the job site are classified in this industry. 1752 Floor laying and other floor work, not elsewhere classified This category includes sp ecial trade contractors primarily engaged in the in stallation of asphalt tile, carpeting, linoleum, and resilient flooring. The industry also includes sp ecial trade contractors engaged in laying, scrapi ng, and finishing parquet and other hardwood flooring. 1761 Roofing, siding, and sheet metal work Special trade contractors primarily engaged in the installation of roofing, si ding, and sheet metal work. Sheet metal work performed by plumbing, heating, and air-conditioning contractors in conjunction with the installation of plumbing, heating, and airconditioning equipment are classified in sic 1711: plumbing, heating, and air-conditioning. 1771 Concrete work Special trade c ontractors primarily engaged in concrete work, including portland cement and asphalt. This industry incl udes the construction of private driveways and walks of all materials. 1781 Water well drilling This category covers special trade contractors primarily engaged in water well drilling. 1791 Structural steel erection This category covers sp ecial trade contractors primarily engaged in the erection of structural steel and of similar products of prestressed or precast concrete.

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387 Table E1. Continued. Code Label Description 1793 Glass and glazing work This category is comprised of establishments primarily engaged in cutting, coating, tinting, and installing glass. Companies that install automotive glass are described in sic 7536: automotive glass replacement shops. 1794 Excavation work This category covers special trade contractors primarily engaged in excavation work and digging foundations, including digging and loading. Contractors in this i ndustry may also perform incidental concrete work. 1795 Wrecking and demolition work This category covers special contractors that primarily wreck and demolish buildings and other structures, except marine property. They may or may not sell material salvaged from demolition sites. 1796 Installation or erection of building equipment not elsewhere classified Special trade contractors primarily engaged in the installation, erection, or dismantling of miscellaneous building equipment make up this industry, which encompasses numerous firms that offer a wide range of services. Common activities include the installation, repair, and dismantling of conveyor systems, dumbwaiters, dust collecting equipment, elevators, incinerators, industrial machinery, power generation devices, revolving doors, and vacuum cleaning systems. 1799 Special trade contractors not elsewhere classified The special trade contractors, not elsewhere classified industry is comprised of a plethora of firms that provide a broad range of miscellaneous construction services. Examples of in dustry activities include bathtub refinishing, gasoline pump installation, grave excavation, swimming pool construction, post hole digging, wallpaper stripping, mobile home setup, house moving, fire escape installation, bowling alley constructi on, artificial turf installation, and sandblasting.

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388 LIST OF REFERENCES Anderson, D, Miller J, and Kalsbeek W (1983): Fi ndings from a major U.S. survey of persons hospitalized with head injuries. Public H ealth Report 98: 475-478. Aspelmaeier J (2002): Multiple comparison handout. Retrieved on April 11, 2007 from http://www.radford.edu/~jaspelme/611/
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389 Dement J M and Lipscomb H (1999): Workers compensation experience pf North Carolina residential construction workers, 1986-1994. App lied Occupational and E nvironmental Hygiene. 14: 97-106. Dement J M, Lipscomb, H, Li, L, Epling, C, and Desai, T (2003): Nail gun injuries among construction workers. Applied Occupational and Environmental Hygiene. 15 (5): 374-383. DeSantis KK, Schneider LW, Rupp J, Eby B, a nd Pearlman M (1999): Challenges in frontal crash protection of pregnant drivers based on anthropometric considerations. Society of Automotive Engineers, 1999-010711; 105-127. Federal Motor Vehi cle Safety Standard No. 208 (1977): Federal Register, Docket 74-14, Notice 11. Vol. 42 (128). Dorevetich S, Forst L, Conroy L and Levy P (2002): Toxic inhalation fatalities of US construction workers, 1990 to 1999. Journal of Occupational and Environmental Medicine. 44 (7): 657-662. Enders LJ and Walker WC (2003) : Work-related low back injuries : An analysis of workers compensation claims in Virginia. Archives of Physical Medicine and Rehabilitation. 84 (9): 116. Exadaktylos AK, Bournakas T, Eggli S, Zimm ermann H and Iizuka T. (2002): Maxillofacial injuries related to work accidents: a new con cept of a hospital-based full electronic occupational trauma surveillance system. Occ upational Medicine. 52 (1): 45-48. Frampton MW and Utell MJ (1995):Inhalation inju ries due to accidental and environmental exposures. Current Opinion in Critical Care. 1 (3): 246-252. Gerr F, Letz R, and Landrigan PJ (1991): U pper extremity musculos keletal disorders of occupational origin. Annual Review of Public Health. 12: 543-566. Ghista DN (1982): Human Body Dynamics: Imp act, Occupational and Athletic Aspects. Oxford: Clarendon Press. Gillen M, Faucett JA, Beaumont JJ, and McLoughlin E (1997): Injury severity associated with nonfatal construction falls. American Jour nal of Industrial Medicine. 32: 647-655. Goldsheydere D, Weiner Shira S, Nordin M, and Hiebert R (2004): Musculoskeletal symptom survey among cement and concrete workers. Work. 23: 111-121. Hannon P and Knapp K (2006): Forensic Biomechanics. Tucson, AZ: L&J Publishing Harrison DH (1979): Nasal injuries: their pathogen esis and treatment. British Journal of Plastic Surgery. 32 (1): 57-64.

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390 Hessel PA (2000): Hearing loss among constructi on workers in Edmonton, Alberta, Canada. Journal of Occupational and Envi ronmental Medicine. 42: 57-63. Hinze J, Devenport J, and Giang G (2006): Analysis of construction worker injuries that do not result in lost time. Journal of Construc tion Engineering and Ma nagement.132 (3): 321-326. Holmstrom E, Moritz U, and Engholm G (1995): Musculoskeletal disorders in construction workers. Occupational Medicine: State of The Art Reviews. 10 (2): 295-312. Horwitz I B and McCall B (2005): An analysis of occupational burn injuri es in Rhode Island: workers compensation claims, 1998 to 2002. Journal of Burn Care and Rehabili tation. 26: 505514. Huang X and Hinze J(2003): Analysis of construction worker fall accidents. Journal of Construction Engineering and Management.129 (3): 262-271. Hunting KL, Welch LS, Nessel-Stephens L, Anderson J, and Mawudeku A (1999): Surveillance of construction worker injuries: The utility of trade-specific an alysis. Applied Occupational and Environmental Hygiene. 14: 459-470. Islam SS, Biswas RS, Nambiar, AM, Syamlal G,Velilla, AM, Ducatman, AM, Doyle, EJ (2001): Incidence and risk of work-rela ted fracture injuries: Experience of a state-managed workers' compensation system. Journal of Occupationa l and Environmental Me dicine. 43(2): 140-146. Islam SS, Doyle EJ, Velilla A, Martin CJ, Du catman AM (2000): Epidemiology of compensable work-related ocular injuries and illnesses: Incide nce and Risk Factors. Journal of Occupational and Environmental Medicine. 42 (6): 575-581. Islam SS, Nambiar AM, Doyle EJ, Velilla AM, Biswas RS, Ducatman P, and Alam M (2000): Epidemiology of work-related burn injuries: Experiences of a state-managed workers compensation system. Journal of Trauma: Inju ry, Infection, and Critical Care. 49 (6): 1045-51. Islam SS, Velilla AM, Doyle EJ,and Ducatman AM (2001): Gender differences in work-related injury/illness: Analysis of workers compensation claims. American Journal of Industrial Medicine.39 (1): 8491. Janicak CA (1998): An examination of occupatio nal fatalities involvi ng impact-related head injuries in the construction industry. Journal of Occupational and Environmental Medicine. 40 (4): 347-350. Jensen LK, and Eenberg W (1996): Occupation as a risk factor for knee disorders. Scandinavian Journal of Work, Environment and Health. 22 (2): 165-175. Jensen LK, Mikkelsen S, Loft IP, and Eenberg W (2000): Work-related knee disorders in floor layers and carpenters. Journal of Occupational & Environmental Me dicine. 42(8):835-842.

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391 Kilburn KH, Warshaw RH, and Hanscom B (1992) : Are hearing loss a nd balance dysfunction linked in construction iron work ers? Occupational and Environmental Medicine.49 (2): 138-141. Kines P (2002): Construction worker s falls through roofs: Fatal ve rsus serious injuries. Journal of Safety Research. 33: 195-208. Kisner S and Fosbroke D (1994) Industry hazards in the construction industry. Journal of Occupational Medicine.36: 137-143. Lewis PM, Ennis O, Kashif A and Dickson WA (2004): Wet cement remains a poorly recognized cause of full-thickness skin burns. In jury. International Journal of Care for the Injured. 35: 982-985. Lipscomb HJ, Glazner J, Bondy J, Lezotte D, and Guarini K (2004): Analysis of text from injury reports imroves understanding of construction falls Journal of Occupational and Environmental Medicine. 46: 1166-1173. Lipscomb HJ, Dement JM, Nolan J, Patterson D, a nd Li L (2003): Nail gun in juries in residential carpentry: Lessons from activ e injury surveillance. Inju ry Prevention. 9 (1): 20-25. Lipscomb HJ, Dement JM, Loomis DP,Silverstein B, and Kalat J (1997): Surveillance of workrelated musculoskeletal injuries among union carpenters. American Journal of Industrial Medicine.32: 629-640. Lipscomb HJ, Dement JM, and Behlman R (2003): Direct costs and patte rns of injuries among residential carpenters, 1995-2000. Journal of O ccupational and Environmental Medicine. 45: 875-880. Lipscomb HJ, Dement JM, Gall, JS, Camer on W, and McDougall V (2000): Work-related injuries in drywall installation. Applied Occupational and Environmental Hygiene. 5 (10): 794802. Lipscomb HJ and Li L (2001): Injuries among t eens employed in the homebuilding industry in North Carolina. Injury Prevention. 7: 205-209 Lipscomb HJ, Dement JM, Nolan J,Patters on D (2006): Nail gun injuries in apprentice carpenters: Risk factors and control measures. American Jour nal of Industrial Medicine. 49 (7): 505-513. Lipscomb HJ, Dement JM, McDougall V, Kala t J (1999): Work-relate d eye injuries among union carpenters. Applied Occupational and Environmental Hygien e. 14 (10): 665-676. Lombardi DA, Pannala R, Sorock GS, Wellman H, Courtney TK, Verma S and Smith GS (2005): Welding related occupational injuries; a narrative analysis. In jury Prevention. 11: 174179.

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395 BIOGRAPHICAL SKETCH Raymond Godfrey was born on June 24, 1961, in Turin, Italy. Raymond earned his bachelors degree in 1984 from the University of Florida majoring in psychology. In May of 1994 Raymond earned a Master of Education in Counseling Education from Florida Atlantic University, in Boca Raton, Florida. In the spri ng of 1999 he was admitted to the M.E. Rinker Sr. School of Building Construction at the University of Florida, where he achieved his masters degree in building construction management. In the fall of 2003, he was admitted to the Ph.D. program in the College of Design, Construction, and Planning at U.F. under the mentorship of Professor Jimmie Hinze. Raymond will begin his academic career in 2007 in the Construction Management program at the University of Southern Mississippi. Raymonds research interests include health and safety in the construction industry, sustainable construction, ethics in cons truction management, and labor relations.