MYOFASCIAL PAIN: A REVIEW Shelley Pullen* _____________ t a b l e hi: a s s o c ia t e d s y m p t o m s ABSTRACT A literature review on myofascial pain, concepts of fibrositis and fibromyalgia are presented. Myofascial pain is discussed as regards its definition, occurrence, behaviour, characteristics and modern approaches to treatment. Theories of the pathology of trigger points are described. Also the myofascial pain-dysfunction syndrome and its clinical recognition are addressed. PART TWO: TRIGGER POINTS An historical overview of the literature relating to muscular pain was presented previously1. In recent studies it has been shown that myofascial pain syn­ dromes are the most common causes of pain that bring patients to chronic pain treatment centres. Among 283 consecutive admissions to a comprehensive pain centre, 85% were diagnosed independently by a neurosurgeon and physiatrist as being sufferers of myofascial syndrome. Fibrositis/Fibromyalgia and myofascial pain are not often clearly defined in the literature, but are now acknowledged as two very different entities. The aetiology of fibromyalgia comprises internal and environ­ mental factors while myofascial pain is associated with chronic or abnormal strains, infections, allergies, nutritional or metabolic fac­ tors and emotional stress. Rogers and Rogers2, Simons3 and Sheon4 compared various aspects of fibrositis/fibromyalgia and myofascial pain. These are summarised in Tables I-III. TABLE I: COMPARISON OF THE DEMOGRAPHY FEATURE FIBROMYALGIA/ FIBROSITIS MYOFASCIAL PAIN SEX PERVALENCE AGE Mainly females fourth most common rheumatic disorder Mainly 4 0 - 6 0 years Both sexes Very common Any age TABLE II: CHARACTERISTICS OF PAIN FEATURE FIBROMYALGIA MYOFASCIAL ONSET LOCATION PAIN TYPE RADIATION TENDERNESS Gradual Three or more Diffuse, deep ache Widespread, Chronic Multiple tender points ( 7 - 12) Acute/Gradual Usually one Sharp, localised Muscle-specific patterns Over Trigger points - one or more The treatment for fibrositis is non-specific and is seldom cured, and use must be made of comprehensive and supportive team therapy. Myofascial pain on the other hand responds well to specific local therapy and is usually cured. FEATURE FIBROMYALGIA MYOFASCIAL MUSCLE SPASM Usually none Present with shortening MUSCLE WEAKNESS Uncommon Common RANGE OF MOTION Not usually restricted Always restricted MUSCLE ACTIVITY Painful diffusely Painful in local areas NODULES/CORD Diffuse tenderness Tend to cluster acute pain LOCAL TWITCH ON PALPATION None Frequent WEATHER SINSITIVE Often Common SKIN ROLL TENDERNESS Usually Occasionally RAYNAUD’S PHENOMENON Not present In acute cases vasodilatation in trigger areas, vasoconstriction on referred zone DIFFERENTIAL DIAGNOSIS OF MYOFASCIAL PAIN Normal muscles do not contain myofascial trigger points; they have no taut bands of muscle fibres; they exhibit no local twitch responses and they do not refer pain in response to applied pressure. Escobar and Ballesteross tabulated a differential diagnosis in myofascial pain syndrome (1987). They included myopathies, arth- ritides, musculoskeletal injuries (eg. tendinitis, bursitis overuse syn­ drome), neurological conditions (eg. neuralgias, radiculopathies), visceral conditions(eg. ischemic heart disease, peptic ulcer), viral or bacterial infections, neoplasm and psychogenic pain or behaviour. The diagnosis of myofascial pain is purely clinical. Histologic studies show that there appears to be no evidence for inflammation, but that something is wrong with the muscle6. The limited EM G studies available suggest an abnormality localised to the trigger point and its associated taut band. This may reflect some kind of reflex hyperirritability, mediated perhaps at a spinal level6. CHARACTERISTICS AND BEHAVIOUR OF MYOFASCIAL TRIGGER POINTS An active trigger point causes pain, while a latent trigger point is clinically silent with respect to pain, but may cause restriction of movement and weakness of the affected muscle. This predisposes to acute attacks of pain. Only active trigger points cause pain, but both active and latent trigger points may cause dysfunction. Normal stresses and strains produce slight tissue damage that usually heals. However, if healing does not occur, areas of hyperex­ citability or structural change in muscle may form. These are called latent trigger points, and the individual may be unaware of their existence. Precipitating factors may activate latent trigger point, thus producing an active trigger point which may in turn be perpetuated by specific factors. Concurrent pathology such as nerve root compression and vis­ ceral and joint diseases may also cause activation or perpetuation of trigger points. Afferent discharge from a compressed nerve root or diseased joint may cause facilitation of a spinal segment, thus acti­ vating a latent trigger point within the same segmental distribution. * BSc (Physiotherapy), MSc student Physiotherapy Department, University o f the Witwatersrand Ithuseng Rehabilitation Centre, Ernest Oppenheimer Hospital, Welkom Physiotherapy, August 1992 Vol 48 no 3 Page 37 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Non-pain symptoms of myofascial trigger points include excessive lacrimation, nasal secretion, pilomotor activity, changes in sweat patterns, electrical skin resistance, vasodilation with dermographia, skin temperature changes and reflex vasoconstriction (coldness lo­ cally). Less frequently one may observe hypoaesthesia and local or general fatigue or fine tremor weakness. Other non-pain symptoms may include postural dizziness, spatial disorientation and disturbed weight perception. Most of these above-mentioned symptoms are specific to myofascial trigger points in specific individual muscles. PATHOPHYSIOLOGY OF MYOFASCIAL TRIGGER POINTS The pathophysiology of myofascial trigger points is poorly under­ stood: Histologic examinations “have revealed areas of fibre de­ generation, proliferation of nuclei, and fatty infiltration. Mast cell degranulation and platelet aggregation have also been seen. D e­ creases in the level of ATP, ADP and AMP have been noted”7. A generally accepted theory coupling the ideas o f Simons, Mel- zack and Simons and Travell is summarised as follows:8. Trauma disturbs the normal or weakened muscle through muscle injury or sustained muscle contraction. These traumas release free calcium within the muscle through disruption of the sarcoplasmic reticulum and, with ATP, stimulate actin and myosin interaction and local contractile and metabolic activity which results in increases in noxious by-products. Substances such as serotonin, histamine, ki- nins, and prostaglandins sensitise and fire Groups 3 and 4 muscle nociceptors, and a reverberatory neural circuit is established be­ tween the nociceptors, the CNS, and the motor units. These afferent inputs converge with other visceral and somatic inputs onto cells in the dorsal horn, which project to higher centres and result in percep­ tion of local and referred pain. These inputs may be facilitated or inhibited by multiple peripherally or centrally initiated alterations in neural input, including those produced by treatment modalities (cold, heat, analgesic medication, massage, trigger point injections, TENS.). The cycle may be perpetuated by protective splinting o f the painful muscle through distorted muscle posture and by avoiding painful stretching of the muscles. Any other perpetuating factors will support the reverberatory circuit. With sustained contractile activity local blood flow decreases with resulting low oxygen tension, depleted ATP reserves and diminished calcium pump. Free calcium continues to interact with ATP to trigger contractile activity, especially if actin and myosin are overlap­ ping within the shortened muscle, and a self-perpetuating cycle is established. Sustained increases in noxious by-products of oxidative metabolism then contribute to the onset o f the organic musculodys- trophic stage, with sensitisation of nociceptors within the interstitial connective tissue at the trigger point and further disruption of the calcium pump. Muscle length has to be restored to prevent further perpetuation of the problem. If the process continues, the muscle bank initially tries to respond with hypertrophy but later breaks down to granular ground substance, eventually resulting in localised fibro- sitis. TREATMENT OF MYOFASCIAL PAIN Palpation is required in order to confirm which muscles are responsible for the myofascial pain. The muscle must be put on a stretch until the fibres of the “taut band” are under tension. The stretch should be on the verge of causing local discomfort only and not the referred pain. Then one should palpate the area feeling for ropey, indurated, tight areas, i.e. the taut band. Localise the spot of maximum tenderness - this is the trigger point. The aim of treatment is to deactivate the trigger point, to increase range of movement, to eliminate perpetuating factors and to restore maximum function. The myofascial trigger point may be treated in the following ways: Injection: This often provides dramatic relief. Local anaesthetics are used and normal saline has also been used to good effect. It has been said that it is just the needle stimulus itself which has the effect and dry needling has become a favourable technique among clini­ cians. In most cases a series of two to five injections is sufficient. Stretch and spray is another technique whereby a trigger point may be deactivated. Vapocoolant sprays, usually ethyl chloride or alcohol sprays, are used. The muscle must be stretched to the end point within the limits of pain. The spray is applied from origin to insertion of the muscle in parallel sweeping strokes, three or four times. At the end of each sweep the muscle is passively stretched to its maximum within the limits of pain, until full range is achieved. Another technique combines injection with spray. This is valuable when a myofascial trigger point remains unresponsive to stretch and spray. The muscle is injected as has been described and is immedi­ ately passively stretched using the stretch and spray technique. Myotherapy is sustained pressure to the myofascial trigger point with sufficient force and for long enough to deactivate the trigger point. This is a valuable technique for muscles which do not respond to stretch and spray, and is in fact useful for any trigger point in any muscle. Less commonly the techniques of stripping massage and ice massage are used. The former is specific stroking of the muscle, deeper and slowly deeper, until the trigger point is felt and then deactivated. The latter technique involves intermittent use of ice instead of using vapocoolant spray. It is applied using the same principles of stretch and spray, but the effects on muscle spasm by excessive use of ice should always be considered. Any of the above-mentioned techniques can be used to deactivate a trigger point. Treatment should always be followed by moist heat (even a hot bath or shower if possible), specific stretching exercises of the affected muscles and rest. If there is.no lasting improvement then there are perpetuating factors which have not been addressed. The consideration of perpetuating factors may include corrective action of mechanical stresses, drug control of depression, inflamma­ tion or pain, management of nutritional inadequacies or metabolic disturbancesand the recognition o f influencing psychological factors. MYOFASCIAL PAIN DYSFUNCTION SYNDROME There is much dental literature on the role of the skeletal muscles in the myofascial pain-dysfunction syndrome (MPD syndrome) and in the temporomandibular joint (TM J) pain-dysfunction syndrome. Travell and Simons4 include the following concepts: The terms MPD syndrome and TMJ dysfunction syndrome over­ lap widely and clinically it is difficult to make a sharp distinction. When the symptoms include pain anywhere throughout the head, neck and jaw, the term craniomandibular syndrome is more appro­ priate. The classical definition of the MPD syndrome is as follows: • Diagnosis requires the presence of one of the following: * A unilateral pain in the ear or periauricular area; * masticatory muscle tenderness; * clicking or popping noises in the TMJ accompanies by pain or tenderness; and * limited opening of the jaw or deviation of the mandible on opening. • In addition there should be no clinical or radiological evidence of organic changes in the TMJ. Three major viewpoints regarding the etiology of MPD syndrome: • muscular origin; • complex psychophysiological phenomenon; and • disturbed occlusal mechanics. Bladsy38 Fisioterapie, Augustus 1992, deel 48 no 3 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) The pain is in fart often referred to the joint from myofascial trigger points in the lateral pterygoid, sometimes the medial ptery­ goid or the masseter muscles. These trigger points can be inactivated in order to relieve the pain and, if necessary, the perpetuating factors must be eliminated to provide lasting relief. CONCLUSION Ashbum concluded that in the case of persistent pain one should realise that this pain is a separate process from the original problem. First any correctable pathology must be ruled out then the pain itself should be addressed . Likewise the possibility of acute pain being myofascial in origin should not be overlooked because all too soon this easily becomes chronic pain. It is this chronic pain which leads to disability, decreased productivity and dramatic effects on the patient’s life. So accurate diagnosis and at least an awareness of the myofascial origins of pain may lead to prompt administration of appropriate treatment and management by a multi-disciplinary team. In this way “most patients will experience significant decreases in their pain, allowing them to return to the workforce and resume a normal life”. REFERENCES 1. Pullen SI. Myofascial pain: A review. SA Journal o f Physiotherapy 1992;48(2)23-25. 2. Rogers EJ, Rogers R. Orthopaedic Review 1989;18(11). 3. Simons DG. Fibrositis/Fibromyalgia: A Form of Myofascial Trigger Points? The American Journal o f Medicine Sept 1986;81 suppl 3A. 4. Sheon RP. Regional myofascial pain and the fibrositis syndrome (fibromyalgia). Comprehensive Therapy 1986;12(9) :42-52. 5. Escobar PL, Ballesteros J. Myofascial Pain Syndrome. Orthopaedic Review Oct 1987;16(10). 6. Campbell SM. Regional Myofascial pain Syndromes. Rheumatic Disease Clinics o f North America Feb 1989;15(1). 7. Ashbum MA, Fine PG. Persistent Pain Following Trauma. Military Medicine Feb 1989;154. 8. Friction JR. Myofascial Pain Syndrome. Neurologic Clinics May 1989;7(2). WORLD CONFEDERATION FOR PHYSICAL THERAPY POSITION STATEMENT* PHYSICAL THERAPY FOR THE CARE OF ELDERLY PERSONS The World Confederation for Physical Therapy Accepting the United Nations’ Principle for Older Persons - Item 10 (New York 1991): “Older persons should have access to health care to help them maintain or regain the optimum level of physical, mental and emotional well-being and to prevent or delay the onset of illness”; Recognising the rapid escalation in the number of elderly persons throughout the world; Appreciating that epidemiological data indicates that 20% or more of elderly persons experience mobility and functional problems which may compromise their well being; Mindful of the financial implications of disability to the elderly indi­ vidual, the family and the community; and Aware that many physical problems may be prevented, corrected or ameliorated by the timely intervention of physical therapists; Urges member organisations to take action by vigorously encoura­ ging legislative and regulatory bodies to incorporate the following principles into their national planning and programmes. • There should be active involvement of physical therapists with appropriate knowledge and experience of the development of services for elderly people in policy and planning at international, national and local levels. • Prompt and coordinated services provided by physical therapists should be promoted as an alternative to high cost hospital or institutional care. • The provision of physical therapy services in the home or in pro­ grammes organised for elderly persons who usually reside at home, such as out-patient clinics, day hospitals, day care centres or respite care programmes, should be promoted as an alternative to high cost hospital or institutional care. • The establishment of physical therapy programmes for those who do not have direct access to mainstream services, for example elderly persons in rural areas. • There should be recognition that functional assessment, especially in the home environment, is necessary to determine the needs of elderly persons, and that physical therapists are key personnel in the management of mobility and physical function problems. • That health promotion programmes conducted by physical thera­ pists and aimed at enhancing physical function, especially in well elderly persons, may contribute subsequently to the development o f optimal health and well-being of elderly persons, • Reimbursement systems should allow for the complex and multiple health problems which elderly persons may have, and take into account the likely slower response to intervention. • The identification o f gaps in services in health and welfare pro­ grammes for elderly people which may be filled by the provision of physical therapy. • The provision of funding for research and programme develop­ ment into aspects of physical therapy relevant to the care of elderly people should receive due recognition. • That physical therapists participate in the education and training programmes for primary health care workers, including families. PHYSICAL THERAPISTS CHART A COURSE FOR OLDER PERSONS Healthcare issues and needs of older persons worldwide were the topics of a collaborative meeting between an international group of physical therapists and representatives of the International Institute of Aging (United Nations) - Malta. As a result of the meeting a pilot short course on physical therapy services for older persons is planned for 1993. The physical therapists present were; Doreen Bauer from the Western Pacific region, Jo Beenhakker from Africa, Neva Greenwald from North America and Margrit List from Europe, along with rap­ porteur, Barbara Sutcliffe and Lois Dyer. Present from INIA were the director, Dr Alfred Grech, D r Julian Mamo, Dr Mario G arrett and Marika Wirth. The final report and proposed curriculum will be issued by INIA, 117 St Pauls Street, Valetta, VLT07, Malta, available on request. PILOT TEST SHORT COURSE At the meeting priority was given to raising awareness of the contribution of physical therapy to services for elderly people and ultimate aims are: • To improve health care services for elderly people by developing relevant physical therapy attitudes, skills and knowledge. • To develop physical therapy skills to influence policy both locally and nationally. The pilot course will address these aims and the resulting curricu­ lum will be available for further courses worldwide. Criteria for selection to the pilot course, costs and funding details will be available from INIA. Applications from developing countries are especially encouraged. * As devised by the Working Party o f Physical Therapists at the meeting with the International Institute of Aging (United Nations) - Malta, in January 1992, as agreed by the WCPT Executive Committee in February 1992, for ratification at the next WCPT General Meeting in Washington in June 1995. Physiotherapy. August 1992 Vol 48 no 3 Page 39 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )