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Effect of Eccentric/Concentric Exercise on Patients with
Petra K. Wilkes
This study seeks to discover the causes of fibromyalgia pain, and to determine the physiological change that
occurs when a person feels pain. Fibromyalgia syndrome is a complex condition characterized by widespread
muscle pain and fatigue. Symptoms include stiffness, headaches, facial pain, sleep disturbances, and
overall sensitivity. Delayed Onset Muscle Soreness (DOMS) is a normal physiological response to increased
exertion, and unfamiliar physical activities, causing strength loss, muscle tenderness, and stiffness. There is
greater incidence of DOMS following eccentric exercise (downhill running and resistance training) rather
than concentric exercise. Participants in the study participated in a series of exercises, both concentric and
eccentric, using the Biodex machine. The hypothesis was not proven. Subjects with fibromyalgia experienced
greater strength than expected, with a non-significant drop in strength and range of motion of the arm.
Deviation from the hypothesis can be due to several factors, including small sample size and strict subject
In a study by D. Maquete conducted at the Universite de Liege in Liege, Belgium, 16 women with FMS and 85
healthy women underwent isokinetic muscle strength (knee), isometric grip strength, muscle fatigue resistance,
and posture maintenance tests. The results of this study showed that all muscle variables were decreased in
FMS subjects as compared to the control population. Pain ratings were also greater in FMS subjects. This
confirmed muscle impairment in FMS patients, especially during aerobic exercise.
The current study seeks to discover the causes of fibromyalgia pain and to observe pain flares in a controlled
manner. The project seeks to determine the physiological change that occurs when a person feels pain. It seeks
to determine the effect of delayed onset muscle soreness on patients with and without fibromyalgia syndrome.
Fibromyalgia Syndrome (FMS)
Fibromyalgia syndrome is a complex condition characterized by widespread muscle pain and fatigue. The name of
the syndrome comes from "fibro" meaning fibrous tissue, "my" meaning muscles, and "algia" meaning
pain.1 Fibromyalgia was first described in 1816 by a surgeon at the University of Edinburgh by the name of
William Balfour. The syndrome has been called by many different titles, and much debate has taken place
regarding this syndrome. The American Medical Association recognized FMS as a true illness in 1987, but very
few doctors still have any training in diagnosing or treating the syndrome today. The difficulty behind a diagnosis
is that there is no blood test, x-ray, or muscle biopsy that can accurately identify the condition. Lab tests are
used simply to rule out other conditions.2
Symptoms associated with fibromyalgia include body stiffness, headaches, facial pain, sleep
disturbances, gastrointestinal problems, depression, anxiety, and overall sensitivity. Patients with fibromyalgia
are also sensitive to smells, sounds, lights, and vibrations. The nerve endings within the body of patients
with fibromyalgia are sensitized and change shape. This is a phenomenon called neuroplasticity, which holds that
pain has the ability to change the nervous system.3 This causes the body to interpret touch, light, and sound as pain.
In 1990, the American College of Rheumatology established the official diagnostic criteria for fibromyalgia.
A diagnosis of fibromyalgia requires more than three months of chronic, widespread muscle pain in all four
quadrants of the body (upper right and left, lower right and left), as well as pain in 11 of 18 tender point
sites.1 Fibromyalgia, like many other pain syndromes, tends to be overrepresented in women.
Delayed Onset Muscle Soreness
Delayed Onset Muscle Soreness (DOMS) is experienced by all individuals, regardless of fitness level and expertise.
It is a normal physiological response to increased exertion, and unfamiliar physical activities. Symptoms
associated with DOMS include strength loss, pain, muscle tenderness, stiffness, and swelling.4 The pain
associated with DOMS typically reaches its peak within 24-48 hours after exercise and subsides within 96 hours. A
full recovery of strength usually takes up to 5 days, pain and tenderness 7 days, and stiffness and swelling 10
days. There is greater incidence of DOMS following eccentric exercise (downhill running and resistance
training) rather than concentric exercise. The mechanism is unique in that the contracting muscle is forced to
be lengthened in eccentric exercise, and shortens in concentric exercise. The concentric contractions
initiate movements, while the eccentric contractions play the role of stopping or slowing the movements.
Individuals normally become stiff and/or sore the following day due to muscle fiber damage.5
The pain of DOMS is believed to result not from lactate buildup in the muscles, but from the body's
inflammatory response to the damage and rearrangement of muscle caused by the exercise. DOMS is
easily overcome with time, as opposed to muscle strains, which become more severe with exercise. In
DOMS, exercise is still possible without further muscle damage.6
The hypothesis is that those subjects with fibromyalgia will experience a greater pain episode than the
control subjects. Neuroplasticity may take effect, with the nervous system being slightly altered by this pain
episode. By the end of the exercise visit, the subjects are expected to exhibit less strength in the exercised arm
than at the beginning of the exercise. The body will have an inflammatory response to the pain. Lower bicep
pain thresholds and faster windup (higher heat and muscle tapping ratings) are expected during the third visit.
The subjects' psychophysical ratings, however, should return back to "baseline" by the 2-week follow-up visit.
Participants were required to meet certain criteria before being enrolled in the study. This criteria included no use
of narcotics, anti-depressants, or NSAIDs, aspirin for cardio-protection only, consistent dosages (if any) of
muscle relaxants, low doses of benzos (if any), and mild osteoporosis (if any). Participants were excluded
from participation in the study if they met any of the following criteria: clinical depressions, diabetes,
lupus, rheumatoid arthritis, inflammatory joint disease, infection, trauma, pain flare, pregnancy, a baseline
pain rating greater than 60 on a scale of 100, or weight lifting exercise within the past 3 months.
Participants were provided with a medication diary to document their daily dosages of medications, an event diary
to document stressful situations and life changes, and a packet of questionnaires related to pain. Subjects with
pain (FMS) were instructed to call the pain call-in hotline to rate the pain felt each day for 1 week prior to their
first visit. Subjects without pain were instructed to begin pain call-in following the DOMS exercise visit (Day 2).
The protocol consists of 4 visits within a time frame of 17 days.
Baseline Visit - Day 1
The first visit served the basis for comparison. This visit included a pain questionnaire completion and
a psychophysical evaluation. During this evaluation, range of motion of the arm was recorded (using goniometer),
as well as measurements of the biceps and forearm (using tape measure), bicep threshold (using digital
algometer), hegu muscle tapping (2X each), thermal heat tapping on the palms of the hand (windup testing of
6 trials with 3 minutes in between each), and thermal heat stimuli on the forearm on 2 spots of each arm.
Subjects rated their pain using the Visual Analog Scale (VAS). A Shade-Me-Sam was also completed,
allowing subjects to shade their areas of pain onto a diagram of the human body. Twenty tender points were
also done on each subject. The subject's ratings from each of the psychophysical testing mechanisms were recorded.
Exercise Visit- Day 2
The pain questionnaire, Shade-Me-Sam, and tender points were repeated during this visit. In order to
minimize interference in daily activities, the subject's non-dominant arm was exercised. The DOMS exercise
protocol consisted of isometric and isotonic exercises, followed by eccentric exercise, all controlled by the
Biodex machine. Participants were seated in the machine sitting straight up with shoulders even and feet on foot
rest. Each was strapped in and provided with a handle for support. The tests were as follows:
1st test: Isometric Unilateral - Subjects instructed to pull on the machine arm for 5 seconds with all of
their might, as it remained in a stationary position. (5 reps)
2nd test: Passive Unilateral (warm-up) - Subjects instructed to pull the machine arm towards them, and to
relax as it moves away. (5 reps)
3rd test: Passive Unilateral (Eccentric Exercise) - The machine arm was pushed up towards the subject,
and the subject was instructed to resist the movement as it moves down. (5 reps)
4th test: Isokinetic Unilateral - DOMS (Eccentric/Concentric) - The machine arm was pushed up towards
the subject, and the subject was instructed to pull the arm towards them when once it gets to the top, and to
resist the movement of the arm as it moves down. (Two sets of 12 repetitions)
5th test: Isometric Unilateral - (Identical to 1st test)
Pain ratings using the VAS were obtained from the subject after each round of exercise. After this visit,
the participant was instructed to call the pain call-in, extend their arm while on the phone, and rate the pain felt on
a scale of 1-10.
Post-Exercise Visit - Day 4
This visit maintained all of the characteristics of the Baseline Visit, except participants were placed in the Biodex
to perform the Isometric Strength Test. This helped to determine whether their level of strength was the same
today as it was prior to the DOMS exercise. The results obtained from this visit were compared to the first to
see what effects, if any, the exercise had on the subject.
Follow-up Visit - Day 17
This visit was a direct repeat of the Post-Exercise Visit. The purpose of this visit was to observe whether or not
the patient's psychophysical evaluation returned to baseline.
RESULTS AND CONCLUSIONS
The results available at the time of publication include data on peak and average torques during exercises. Data
from the psychophysical evaluations has not been provided.
Data were collected on 10 control subjects and 8 subjects with fibromyalgia. The data from the Biodex machine
are provided in Tables 1-4. The analyzed results are provided in Figures 1-3. Figure 1 depicts the Average
Peak Torque for each group during the isometric exercises. The peak torque for the control group decreased by
41% during the isometric exercises before and following the eccentric/concentric exercises. The peak torque for
the FMS group decreased by 22% for the same reading.
Peak Torque (Control Group)
Isometric 1 Warm-Up Ecc Ecc/Con Isometric 2
24.3 33.4 25.5 17.4 10.7
20.6 25.5 24.7 18.7 16.6
26.2 29.3 25.7 18.5 12.4
22.7 30.7 27.8 24.3 14.6
23.7 31 24.6 17.8 12.9
16.2 14.4 12.4 12.2 8.6
29.7 33.5 30.7 21.2 16.5
26.7 33.4 25.8 22.6 15.5
30.8 39 33.5 26.5 16.9
36.5 34 29.1 26.7 26.8
Peak Torque (FMS Group)
Isometric 1 Warm-Up Ecc Ecc/Con Isometric 2
33.1 37.1 32.7 30.5 31.3
27.2 26.2 26.3
13 38.9 22.1 12.9 8.2
20.5 22.5 17.8 14.6 17.3
20.5 27.7 24.1 21.9 16.4
24.2 33.9 24.3 22.8 22.6
21.1 37.9 24.5 21.1 13.1
Range of Motion (Control Group)
Warm-Up Ecc Ecc/Con
148.7 146.9 147.2
129.4 116 92.7
144.7 142 142.5
141.8 129.8 129.7
146.4 142.7 143.3
163.2 133.3 133.5
147.7 147.5 147.5
157.8 148.8 149.3
148.2 145.1 145
138.6 98.7 98.8
Range of Motion (FMS Group)
Warm-Up Ecc Ecc/Con
140.1 124.7 124.9
129.5 99.9 99.8
124.7 103.2 103.3
138.9 120.9 120.3
Isometric Peak Torque
Figure 1. Average Peak Torque for each group during the isometric exercises
Figure 2 depicts the Average Torque for both groups during the series of eccentric and concentric exercises.
The average torque for the control group decreased by 32% during the exercises, while the average
torque decreased by 28% for the FMS group.
Figure 2. Average Torque for both groups during the series of eccentric and concentric exercises
In Figure 3, the Range of Motion of the arm during the eccentric/concentric exercises is depicted. The range
of motion fore the control group decreased by 9%, while that of the FMS group decreased by 14%.
Range of Motion
Figure 3. Range of Motion of the arm during the eccentric/concentric exercises
The results did not prove the hypothesis to be correct. Both groups experienced a decrease in strength, as
evidenced by the decreases in torque; however, the control group experienced a greater decrease than those
with FMS. This was unexpected, but true for every category.
The range of motion for the FMS group decreased by an amount greater than the control group, which was stated
in the hypothesis. Subjects with fibromyalgia were expected to exhibit less strength than the normal controls,
which was the case at the beginning of the exercises. However, their strength did not fall of as quickly as the
The variation from the hypothesis can be due to several factors. The small size of the groups may have played a
role in the accuracy of the outcomes. Since the enrollment and exclusion criteria for the study is very strict,
the fibromyalgia group may not be an accurate representation of patients with fibromyalgia. Those that qualified
may have been on the "stronger" end of fibromyalgia patients, and may have thus affected the outcomes.
1. FMS Monograph: An Overview of the Fundamental Features of Fibromyalgia Syndrome. National
Fibromyalgia Partnership, 1999.
2. Starlanyl D, Copeland ME. Fibromyalgia and chronic myofascial pain syndrome: a survival manual. Oakland CA:
New Harbinger Publications; 1996.
3. Staud, R. The abnormal central pain processing mechanism in patients with fibromyalgia. Fibromyalgia
Frontiers. 2002; 10
4. Connolly, DAJ, Sayers SP, McHugh MP. Treatment and prevention of delayed onset muscle soreness. J.
Strength Cond. Res. 2003; 17:197-298.
5. Proske U, Morgan DL. Muscle Damage from eccentric exercise: mechanism, mechanical signs, adaptation, and
clinical applications. Journal of Physiology 2001;537:333-345.
6. Szymanski DJ. Recommendations for the avoidance of delayed-onset muscle soreness. J. Strength Cond.
7. Maquet D, Croiser J, Renard C, and Crielaard J. "Muscle Performance in Patients with Fibromyalgia."
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