Fibromyalgia syndrome: an overview.

Fibromyalgia syndrome (FS) is a chronic pain disorder of unknown etiology characterized by widespread musculoskeletal aches and pains, stiffness, and general fatigue. Frequently misdiagnosed, FS is often confused with myofascial pain syndrome, polymyalgia rheumatica, polymyositis, hypothyroidism, metastatic carcinoma, rheumatoid arthritis (RA), juvenile rheumatoid arthritis, chronic fatigue syndrome, or systemic lupus erythematosus, any of which may occur concomitantly with FS.[1,2] Fibromyalgia syndrome is the third most commonly diagnosed rheumatic disorder (after osteoarthritis and RA). The median age of onset for FS is from 29 to 37 years, whereas the age of medical presentation (formal diagnosis) for FS is 34 to 53 years, indicating that most patients endure symptoms for several years before receiving an appropriate diagnosis.[3](p228) In the United States, 3 to 6 million people may have symptoms of FS, and an estimated 15% to 20% of patients (90% of them women) seen in rheumatology practices have fibromyalgia.[4](p24)

The etiology for FS is unknown. Prior to 1976, FS was often referred to as "nonarticular rheumatism," as opposed to RA and osteoarthritis, or as "psychogenic rheumatism" due to the lack of an objective diagnosis.[3] In 1976, Hench introduced the term "fibromyalgia" ("-algia" meaning pain in fibrous tissue) to replace the misnomer "fibrosis" (based on an assumed, but unsubstantiated, "inflammation" of fibrous tissue), coined by Gowers in 1904.[3]

Symptoms

The five musculoskeletal or fibrous connective tissue symptoms most frequently reported are (1) aches and pains, (2) stiffness, (3) swelling in soft tissue, (4) tender points, and (5) muscle spasms or nodules. The characteristic aches and pains are most often described as a diffuse, widespread, or general achiness that fluctuates through the full range of pain sensations and that is frequently accompanied by marked stiffness. Swelling is reported in articular tissue, periarticular tissue, or soft tissue.[5] The self-reported tender points,

[Krsnich-Shriwise S. Fibromyalgia syndrome: an overview. Phys Ther. 1997;77:68-75.]

Key Words: Fibromyalgia syndrome, Nonrapid eye movement (stage IV) sleep, Serotonin, Somatomedin C, Substance P, Tender point/trigger point. frequently accompanied by muscle spasms or nodules, are critical to the diagnosis of FS. Tender points cluster in regions around the neck and shoulders, the upper chest wall, and the lower back.[1](pp165-166)

Other symptoms reported by patients with FS include excessive fatigue, nonrestorative sleep with morning fatigue (60%-90%), chronic tension and migraine headaches (28%-58%), bowel and bladder irritability (34%-53%), dysmenorrhea, paresthesia, Raynaud's phenomenon (30%), chest pains, anxiety, depression (20%), and swelling and numbness of the extremities.[1,3,6]

Concomitant findings may include those symptoms and conditions previously mentioned, as well as weakness, mitral valve prolapse, tachycardia, hypermobility syndrome, cognitive problems (thinking, concentration, and memory), vertigo, tinnitus, tendinitis, bursitis, sicca syndrome (dry skin, dry eyes, dry mouth), reticular skin discoloration (skin mottling), temporomandibular joint dysfunction, sciatica, and lupus.[1,2,6]

Diagnosis

Prior to 1990, diagnosis of FS was exclusionary and based on subjective data. In an effort to systematically define this syndrome, the Second World Congress on Myofascial Pain and Fibromyalgia issued the "Copenhagen Declaration," establishing fibromyalgia as a distinctive diagnosis.[4,6] In 1990, the American College of Rheumatology concluded that fibromyalgia could be diagnosed by a history of widespread pain occurring for longer than 3 months in combination with pain in 11 or more out of 18 specified, bilateral tender points in muscular tissue.[4,6,18] The Table presents the American College of Rheumatology's 1990 criteria for the classification of fibromyalgia,[4](p26) and the Figure illustrates the anatomic locations of tender points according to these criteria.[4](p38)

Although the terms "tender points" and "trigger points" are used interchangeably throughout the literature, FS is identified by fixed tender points, as opposed to trigger points. Citing Travell and Simons,[8] Hubbard and Berkoff[9] define a trigger point as a localized spot within a firm area of muscle (the taut band) that elicits a characteristic pattern of radiating pain, tingling, or numbness in response to sustained pressure. In contrast, tender points, which can occur in muscle, ligament, tendon, or periosteal tissue, localize rather than refer pain to adjacent areas upon sustained stimulation.[1,5] Tender points are palpated bilaterally at each site using the thumb or the first two fingers to apply steady, uniform pressure (4 kg/[cm.sup.2]) firmly enough to blanch the examiner's thumbnail.[5,10] Dolorimetry does not perform as well in diagnosis as does digital examination.10(p489) Most patients with FS have tender-point thresholds at 2 kg/[cm.sup.2]. The examiner palpates over the site gently and feels for "spasm" while examining the skin for tenderness or redness. The examiner applies increasing pressure with a thumb or one finger until the patient (1) tells the examiner to stop because of pain, (2) withdraws, or (3) grimaces. The site should then be examined for erythema "flare."(1)(p166) Reeves et al[5](p19) suggest the following tender-point index: 0=no tenderness, 1=tenderness with no withdrawal, 2=tenderness and withdrawal, 3=tenderness and exaggerated withdrawal, and 4=untouchable.

A medical history, including a physical examination and a neurological evaluation, is essential for diagnosis of FS. The presence of muscle spasm, nodules, reticular skin discoloration (mottling), and a nonrestorative sleep pattern is characteristic.[3,6,10] A simple diagnosis of FS is indicated by normal results on routine laboratory tests, roentgenograms, neurological examinations, and joint range-of-motion examinations.[3] Because FS often occurs simultaneously with other conditions, additional tests may be needed to identify concomitant conditions. The presence of a second clinical disorder does not exclude the diagnosis of fibromyalgia.[11] (p26)

Etiology

The multifactorial features of FS contribute to its unknown etiology. Although it is not within the scope of this overview to address each possible feature, the following six areas are potentially significant: deprivation of restorative sleep, neurobiochemical abnormalities, loss of sympathetic nervous system control, local tissue factors, physical trauma and viruses, and psychological factors.[1,3,6,12]

Deprivation of Restorative Sleep

Electroencephalographic data give evidence of rapid alpha-wave intrusion into slower delta-wave (stage IV, nonrapid eye movement [NREM]) deep-sleep periods as well as other sleep stages.[3,6] Patients with FS experience about 60% alpha-wave intrusion of NREM sleep, as compared with a 25% alpha-wave intrusion rate in control subjects and in persons with insomnia and dysthymia.[3] When control subjects experienced this phenomenon, they experienced muscle fatigue and tenderness over tender points considered diagnostic of FS.[3] Concomitant nocturnal myoclonus and sleep apnea (especially in men) can further decrease restorative sleep patterns.[2]

Neurobiochemical Abnormalities

The amino acid, tryptophan, is the precursor of serotonin, an important neurotransmitter in the pathways serving stage IV sleep as well as the inhibitory descending pain pathways.[6] Evidence of reduced concentrations of tryptophan in relation to other plasma amino acids and of decreased by-products of brain tryptophan metabolism suggests an abnormality in serotonin metabolism.[6] When serotonin is depleted, there is a decrease in restorative NREM sleep and an increase in somatic complaints, depression, and perceived pain.[3] Although other studies have challenged these findings, drug trials offer support. Researchers hypothesize that the beneficial effects of tricyclic compounds, such as amitryptyline and cyclobenzaprine, are due to their blocking the reuptake of serotonin at the synaptic cleft.[3] This hypothesis correlates with previous hypotheses of FS as a pain perception or arousal disorder.

Another biochemical hypothesis centers on substance P, a neuropeptide involved in pain transmission of peripheral nociceptive stimuli from neural dorsal root fibers to high brain centers.[3,6] Higher levels of substance P have been linked with evidence of sadness, inner tension, concentration difficulties, pain, memory disturbance, and the "wheel and flare" reaction often observed in response to light skin scratching.[3,6] The mechanism of action for substance P remains inconclusive. It is speculated that endorphins, opioid neuropeptides that increase in concentration with exercise, may serve to modulate pain sensation by inhibiting the release of substance P at the axonal level.[3]

Sympathetic Nervous System Involvement

Hubbard and Berkhoff[9] have provided anatomical evidence of sympathetic innervation of intrafusal muscle-spindle fibers in cats. Although it is unknown whether this innervation occurs in the muscles of humans, this finding suggests the need for research in explaining symptoms of widespread local tension, previously attributed to extrafusal muscle fiber when exacerbated by stress (de, trauma, lack of sleep, exercise).[5] Goldenberg[1] postulates that sympathetic activity, as reflected by alterations in muscle tissue microcirculation, may contribute to muscle hypoxia, especially following exercise, in patients with fibromyalgia. This muscle hypoxia may be linked to the excessive muscle tenderness. fatigue, and increasing pain that patients with FS have reported experiencing 25 to 48 hours following repetitive exercise.[6]

Local Tissue Factors

Contradicting past studies using trapezius muscle tissue biopsies of patients with FS, Drews et al[13] investigated specific anatomical changes in quadriceps femoris muscle tissue biopsies of patients with FS and found no definite evidence of muscle disease (inflammation or myopathy). Nonspecific findings of atrophic angular fibers and filamentous disarray were noted, however, with irregular cristae patterns in mitochondria and lipofuscin inclusions (manifestations of cell damage). [2, 6, 13] These findings might be caused by metabolic disorders in conjunction with muscle hypoxia.[3,13] Norregaard et al[14] argue that fibromyalgia is not a progressive muscle disease.

Another recent study[15] confirmed previous findings of pronounced decreased voluntary muscle strength in patients with FS, demonstrating a decrease of 30% to 40% of estimated "true" muscle strength per cross-sectional area. Voluntary endurance (as demonstrated by timed periods of repeated contractions performed at 50% of estimated "true" muscle strength performed until exhaustion or maximally for 40 minutes) time, concentration rate, and relaxation rate were similar between patients with FS and control subjects.[15] Because physical immobilization is known to decrease muscle force production more than muscle area, the low activity levels that are common in patients with FS suggest a strength deficit.[15] In a 4-year follow-up study,[14] muscle strength was found to be correlated to the number of tender points, indicating that pain may be a strong deterrent to muscle contraction.

Bennett et al[16] found low serum levels of a growth hormone, somatomedin C, in 70 female patients with fibromyalgia. Somatomedin C is the major mediator of growth hormone anabolic action and is a prerequisite for normal homeostasis. Approximately 80% of the total daily production of growth hormone is secreted during stage IV sleep.[16](p115) Patients with FS experience a decrease in stage IV sleep, which would account for the low serum levels of somatomedin C. Due to somatomedin C's critical role in muscle homeostasis, reduced levels of this hormone may be linked to lack of proper muscle tissue repair and excessive postexertional muscle tissue microtrauma in patients with FS.[6]

Physical Trauma and Viral Onset

Most patients with fibromyalgia can identify no single factor as having initiated their condition. In other patients, physical trauma and a viral illness have been the two most common suspected precipitating events.[1](p170)

A muscle strain from overreaction or repetitive action,[5] a motor vehicle accident, or a fall left untreated may develop into FS. Viral onset is often linked to immuno-logical dysregulation.[3] Although researchers have investigated possible correlations between FS and Epstein-Barr syndrome, human immunodeficiency virus infection, parvovirus B12, and Lyme disease, no conclusive causal relationships have been documented to date.

Psychological Factors

This hypothesis centers on the psychological symptoms of anxiety and depression as associated with FS. The dispute continues as to whether FS should be regarded as a psychogenic disorder or as a somatic expression of a major affective disorder.[17,19]

The search for a possible psychological link to FS etiology is severely hampered by an inability to separate symptoms of depression that may have existed before the onset of FS from symptoms that may be a manifestation of chronic illness.[1,7] Bennett and McCain[19] suggest that whether depression precedes, accompanies, or follows the onset of fibromyalgia, the two components are separate. That is, fibromyalgia will remain after the depression is treated. Nevertheless, when patients are less depressed, they may be better able to deal with their fibromyalgia. [19](p.37)

Patients with FS generally note that stress exacerbates their symptoms.[1] These symptoms are the second leading cause of work-related disability in the United States.[5](p49-50) Cognitive factors, such as a person's expectations (worries, anxieties) or beliefs, play a role in adaptation to chronic disease by modulating emotional or behavioral reactions.[20][p484) Citing Bandura,[21] Buckelew et al[22] state that self-efficacy refers to a person's belief that he or she can competently cope with a challenging situation. Individuals with low self-efficacy more quickly discontinue coping strategies because they anticipate failure.[22] In contrast, higher levels of self-efficacy are associated with better outcomes (improved pain and physical activity scores) and may mediate the effectiveness of rehabilitation-based treatment programs for fibromyalgia.[22]

Management and Interventions

Although no single treatment for FS is available, management of its symptoms is possible. Management programs reported to date have not led to long-term relief of pain or other symptoms.[23](p523) The management of FS often begins with a thorough examination and a diagnosis from a physician who is formally trained in tender-point/trigger-point recognition.[5,16,24] An initial diagnosis provides reassurance to the patient and often reduces the anxiety and depression patterns associated with FS.[24] Most patients experience a feeling of relief to know that their symptoms are "real," due to a recognized syndrome, and perhaps can be treated.[11](p21) Further assurance is afforded to the patient through a proactive team approach involving the patient and his or her physician, physical therapist, and occupational therapist. Other team members might include a clinical nurse, a biofeedback technician, and a psychologist/ psychiatrist.[2,5,11]

The most common goals in the management of FS are (1) to break the pain cycle, (2) to restore sleep patterns, and (3) to increase functional activity levels.[24-26] Because FS is a multifactorial syndrome, it is likely that the best treatment will encompass multiple Strategies.25 (p714)

Education

Burckhardt et al[25] noted that self-efficacy was enhanced in a long-term follow-up study of patients with FS who participated in an educational intervention program. Patients with FS appear to think that they can change or do something about their problems (stressors) but that they need to know more before they can act.[23](p528) Other authors[2,5,11,19,24] have suggested that patients should be instructed in the FS disease process and coping strategies, including stress recognition and management, sleep patterns, nutrition, energy conservation, pain management and cognitive-behavioral intervention programs, medication, and physical conditioning.

Nutritional education includes caution in the use of caffeine, alcohol, and nicotine to increase restorative sleep patterns and improve energy levels.[2,17,24] Carbohydrates enhance the production of serotonin naturally when they are not taken with a protein.[2](p.47) Sugar also increases serotonin; however, carbohydrates increase serotonin for a longer period than does sugar.[2](p47) Suggested nutritional supplements include calcium and magnesium (1,000-1,500 mg per day, to be taken at night), B-complex, or a good multivitamin.[2](p48)

Education in energy-conservation techniques includes improvement of time-management skills in an effort to develop a productive, balanced lifestyle pace that is in accord with available energy levels and required energy restoration time.[2] It encompasses postural exercises and proper body mechanics to minimize constant muscular energy requirements[2,5,19,26] as well as the use of assistive devices to minimize muscle strength requirements and possible strain due to the hypermobility that is often typical of patients with FS.[5,6]

With FS, frequent symptom aggravators include poor sleep patterns, fatigue, mental trauma (worry, anxiety, depression, lack of support systems), physical trauma (repetitive or excessive physical activity), prolonged inactivity, excess weight, poor posture, poor nutrition, and weather changes. Bolwijn et al[p27] report that in most patient networks, the personal needs of the patient with FS or RA have to be fulfilled by just one or two members-often a spouse or a physician. These patients are less likely to take the initiative to meet new people, and patients with FS display a lack of initiative in maintaining relationships.[27](p49) To assist in stress management, a patient may be referred to a support group, and a patient with moderate to severe stress may be referred for psychological or psychiatric counseling.[11,23] Kaplan et al[28] demonstrated positive results with a mindfulness meditation approach that combines the benefits of meditation and cognitive therapy. The efficiency of this approach was attributed to an uncoupling of the sensory component of the pain from the cognitive and affective dimensions of the pain.[28](p284) Other cognitive behavioral therapeutic techniques include meditation, spiritual aids, relaxation tapes and breathing, hypnosis, yoga, tai chi, and biofeedback.[2,8,19,29](p23)

Medications

A national study(30) showed that patients with fibromyalgia may take an average of three of the following medications: a nonsteroidal analgesic (33%), an antidepressant (69%), a muscle relaxant (13%), benzodiazepine (15%), and sometimes a narcotic analgesic (37%) [24](p30) Medications prescribed for the management of symptoms of FS address pain and poor sleep patterns.[24] Nonsteroidal anti-inflammatory drugs or nonnarcotic analgesics (eg, acetaminophen) offer some patients short-term relief.[11,19,26] Tricyclic antidepressants (amitriptyline) or muscle relaxants (cyclobenzaprine) are prescribed because they appear to lessen stage IV sleep disturbance and are thought to increase levels of brain serotonin and other neurotransmitters.[1](p72) Either medication can cause fatigue or morning lethargy.[11,24] Tricyclic antidepressants are administered before bedtime and usually at dosages ranging between 10 and 30 mg per day to control the symptoms of FS (much smaller than dosages used to treat major depression), and they seem to reduce morning stiffness and induce a more restful sleep, with a resultant increase in overall energy level.[11,24] Cyclobenzaprine is administered at a dosage of 5 mg per day, once a day, 1 to 2 hours before bedtime.[11](p26) It has been shown to reduce pain, increase total sleep time, and slightly reduce evening fatigue.[24](p31) Fluoxetine hydrochloride, a selective serotonin reuptake inhibitor (SSRI), offers an alternative to the tricyclic antidepressants, although it may prove to be too stimulating and may exacerbate sleep disturbances.[19](p38) Some clinicians manage the problem by prescribing an SSRI in the morning and a tricyclic antidepressant at night.[19](38) In addition to tricyclic antidepressants, patients are instructed in sleep preparation and sleep habits to assist in maintaining restorative sleep patterns.[2,11]

Corticosteroids, immunosuppressive drugs, and narcotic analgesics are contraindicated because their withdrawal often induces a syndrome with many of the symptoms of fibromyalgia.[11](p.26),[24,26] No drug therapy alone has been described as able to help these patients in the long term.[23](p327)

Exercise

The other most effective intervention for long-term management of FS to date is physical exercise.[19,23,25] Deconditioned muscles use energy sources poorly, contributing to fatigue, and are believed by some therapists to be susceptible to microtrauma, which may contribute to pain.[11](p22) One study has shown that women with FS have lower physical functioning scores on all variables when compared with control subjects or published norms.[31](p213) These patients isometric shoulder muscle endurance reached 37% of the endurance levels of control subjects, perhaps explaining some of the difficulty these women have with carrying tasks, pushing and pulling, and working with the arms held away from the body.[31])(p126) Active elevation of the arms in flexion (mean flexion [approximate] 145[degress]) and abduction (mean abduction [approximate] 130[degrees]) was also impaired.[31](p127) Pain at rest in the shoulders was quite low in the group but increased during active motion exercise.[31](p127) Tender-point pain correlated highly with muscle strength (all upper-body functioning measures and quadriceps femoris muscle strength); however, it was not found to correlate with walking distance and flexibility.[14,31]

Physical therapists should evaluate pain, tender points, range of motion, and strength. Citing Press, Sherman[26](p.169) stated that the key to initiating an appropriate exercise program is an individualized regimen that respects the patient's limitations but does not bow to them. A program should consist of postural exercises; passive stretching; low-load, low-repetition strengthening; and a low-impact aerobic component (cycling, swimming, walking) [5,11,26,29](p.13) Maximum stretching will cause discomfort and will result in limited rather than increased range of movement. The basic rule is to never exceed existing pain limits. Stretching to pain may also stretch nerves, resulting in neural tension.[5]

Bennett and McCain[19] advocate the following aerobic exercise guidelines for patients with FS: a frequency of three times a week, at a pulse rate of 85% of the target heart rate for age (for most adults, 120-150 beats per minute), for a duration of 40 minutes.

Citing Press, Sherman[26](169) reported that patients with FS who are in pain and poor condition need to begin at a very low level of exercise for 5 minutes a day and then increase the duration of activity by 1 minute per session every 3 to 4 days, gradually building to 30 or 40 minutes of exercise three or four times a week. Increases in speed should occur in stride frequency while the patient maintains proper body mechanics with an efficient stride length to avoid fostering hypermobility.[5] Although Nichols and Glenn[32] found inconclusive evidence of beneficial effects of aerobic walking on the symptoms of FS, there were trends suggestive of beneficial responses (lower psychological and pain ratings). In contrast, Granges et al[23](p.53) found that regular physical exercise, rather than drugs or specific physical therapy approaches, correlated highly with low symptomatic FS activity scores. Burckhardt et al[25](p75) recommend the use of the Fibromyalgia Impact Questionnaire, a 10-item instrument that measures physical functioning, pain, depression, anxiety, fatigue, morning tiredness, stiffness, job difficulty, and overall well-being, for treatment evaluation.

Aquatic therapy is often recommended as a desirable and beneficial aerobic activity, especially for patients with FS who have injuries, are overweight, or are sensitive to axial load,[10,11] because it permits a tremendous amount of upper-body activity and endurance activity without putting undue demands on the trunk.[33](p123) Compliance with exercise interventions perhaps can be improved by greater supervision and encouragement with a team management approach and by exercising regularly as a lifelong habit.[19]

Physical therapists can instruct patients in the use of heat at home (moist hot packs, heating pads, whirlpools, warm showers or baths, and hot pads) to increase local blood flow and to decrease muscle spasm and tension.[11] Physical therapists can also instruct patients in the proper use of cold modalities (ice packs, ice massage, and cool baths) to anesthetize localized areas of pain (tender points) and break the pain cycle. Massage and tender-point massage also may promote muscle relaxation. [2,5,24] Pioro-Boisset et al[29](p16) report that patients who pursued alternative medical interventions most frequently consulted chiropractors but generally expressed the most satisfaction with massage therapy when a more toned-down and less rigorous massage was used. In addition, Deluze et al[34](p1250) state that acupuncture, and especially electroacupuncture, when using traditional acupuncture sites for needle insertion as opposed to tender-point sites, has been shown to raise pain threshold levels by 70% in patients with FS. Particular care should be taken that the patient does not become reliant on modalities provided by the therapist for the long-term management of fibromyalgia.[11](p22)

Fibromyalgia syndrome is a multifactorial condition with an unknown etiology and no proven effective long-term management program. Great strides, however, have been made in research since diagnostic guidelines were established in 1990. To date, the two most important interventions for the long-term management of FS are patient education and physical exercise.

Acknowledgments

Appreciation is expressed to Darlene Anderson for secretarial assistance; Jim Dronberger, PT, MB, Assistant Professor in Physical Therapy Education, Rockhurst College, for serving as advisor; and William F Haefele, PhD, Associate Professor of Psychology, Rockhurst College, for his encouragement.

[Figure ILLUSTRATION OMITTED]

Table. American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia(a)

History of widespread pain

Definition: Pain is considered widespread when all of the
following are present:

[] Pain in the left side of the body

[] Pain in the right side of the body

[] Pain above the waist

[] Pain below the waist

[] Axial skeletal pain (cervical spine or anterior chest or
thoracic spine or low back)

In this definition, shoulder and buttock pain is considered as pain
for each involved side. Low back pain is considered lower
segment pain.

Pain in 11 of 18 tender-point sites on digital palpation(b)

Definition: Pain, on digital palpation, must be present in at least
11 of the following 18 tender-point sites:

[] Occiput: Bilateral, at the suboccipital muscle insertions

[] Low cervical: Bilateral at the anterior aspects of the
intertransverse spaces at C5-C7

[] Trapezius: Bilateral, at the midpoint of the upper border

[] Supraspinatus: Bilateral, at origins above the scapular spine
near the medial barder

[] Second rib: Bilateral, at the second costochondral junctions,
just lateral to the junctions on upper surfaces

[] Lateral epicondyle: Bilateral, 2 cm distal to the epicondyles

[] Gluteal: Bilateral, in upper outer quadrants of buttocks in
anterior fold of muscle

[] Greater trochanter: Bilateral, posterior to the trochanteric
prominence

[] Knees: Bilateral, at the medial fat pad proximal to the joint
line

(a) For classification purposes, patients are said to have fibromyalgia if both criteria are satisfied. Widespread pain must have been present for at least 3 months. The presence of a second clinical disorder does not exclude the diagnosis of fibromyalgia. Adapted and reprinted with permission from Wolfe F, Smythe HA, Yunus MB, et al. The American College of Rheumatology 1990 criteria for the classification of fibromyalgia: report of the Multicenter Criteria Committee. Arthritis Rheum. 1990;33:160-172.

(b) Digital palpation should be performed with an approximate force of 4 kg. For a tender point to be considered positive, the patient must state that the palpation was "painful"; a reply of tender" is not to be considered painful.

References

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S Krsnich-Shriwise, PT, is Physical Therapist, Shawnee Mission Medical Center, 9100 W 74th St, Shawnee Mission, KS 66204 (USA). At the time this article was written, she was a student in the master's degree program, Department of Physical Therapy, Rockhurst College, Kansas City, MO 64110.

This article is a revised version of a student presentation at the spring conference of the Missouri Physical Therapy Association on April 29, 1995.