MPS Treatment Methods
Myofascial pain syndrome is a regional pain syndrome that arises from specific trigger points in a muscle or its fascia. Trigger points are discrete focal tender points that are hypersensitive and produce pain locally on palpation as well as distally in a referred muscle group found in a referral pattern. Trigger points are found more commonly in women and in patients 30-49 years of age.1 Myofascial pain is more commonly found in those who are sedentary, thus, it appears that a physically active lifestyle helps to protect against the development of myofascial pain.1
Signs and symptoms of myofascial pain include pain with certain bodily movements, tenderness and aches, stiffness, muscle spasms, and limitation in the range of motion of these areas. In addition, certain autonomic events may present within the affected anatomic region. These findings may include blanching, coldness, sweating, piloerection, and erythema of the skin as well as within the distal referral pattern of pain.2
Trigger points are located in multiple regions of the body involving more than one muscle group. Most commonly, trigger points develop in the neck, shoulders, low back, and extremities. On examination, palpation of a trigger point yields a palpable, tender nodule that may produce a mild, moderate, or excruciating pain response along with a subtle or more noticeable muscle twitch. Referral of pain may be noted in that particular muscle group or another muscle group.
Trigger points can be classified as active or latent. Active trigger points can cause a dull aching pain at rest and, when palpated, the pain can radiate to a referred site. Latent trigger points do not usually cause pain at rest but can cause localized or referred pain with physical stimulation. Latent trigger points may remain in a muscle for many years after an injury, contributing to the injury pool theory.4-7 This theory suggests that these latent trigger points remain in repose and manifest as a minimal decrease in range of motion, coolness, and quick fatigability of the muscle group.2 Once such an injury pool of latent trigger points is present, even a small stressor to this region can cause severe, excruciating pain as well as prolonged edema, loss of range of motion, and a slow recovery period which can be construed as psychosomatic.3
Latent trigger points may be activated by a multitude of stimuli, such as heat or cold, including cold, damp weather and air conditioning. Other factors include a change in heel height, working at surfaces that are too low, sitting in an overstuffed chair, vibrations from riding in an airplane or automobile, and walking in leather-soled shoes on waxed floors commonly found in shopping malls and public institutions.3 Latent trigger point pain may also develop slowly, involving daily microtrauma sustained from repetitive motions, such as typing in a seated position, leading to fatigue.3
The diagnosis of myofascial pain syndrome rests on a thorough history obtained from the patient as well as a complete physical examination. The patient may present after having seen several other clinicians without a clear diagnosis and having had extensive lab and radiological workups that are usually negative. In the history, the patient may relate an acute event (such as a motor vehicle accident) as the etiology of the pain. The patient may also report a chronic event many months or years ago causing the pain. Or, the pain may be insidious. The nature of pain may be described as dull, achy, and persistent. Certain bodily movements and positions may intensify the pain since certain regional muscle groups containing the trigger points are aggravated by these positional changes.
The pain may occur at rest or with physical exertion. It is usually unilateral and need not follow a dermatomal pattern. There may be indirect activation by other trigger points, visceral diseases, arthritic conditions, and emotional stimuli.2
Commonly associated nonpainful phenomena such as autonomic, proprioceptive, and hemodynamic changes may occur. Common autonomic alterations include signs of vasoconstriction, alterations in diaphoresis (either increased or decreased), lacrimation, nasal stuffiness (when head and neck myofascial pain syndrome exists), pilomotor activity, and temperature changes.2 Patients may experience poor sleeping patterns and feelings of depression.
Major and minor criteria have been proposed to aid in diagnosing myofascial pain syndrome. The five needed major criteria include:
- Regional location of pain
- Pain in the expected referred site
- Palpable taut band in a muscle
- Exquisite spot tenderness at one point in the taut band
- Some degree of restricted motion when measurable
Physical or occupational therapy involves stretching and limbering exercises designed to help restore muscle elasticity and length.
Minor criteria includes:
- Reproduction of the pain by palpating the tender spot
- Local twitch response by snapping palpation or needle insertion into the tender spot
- Pain alleviation by muscle stretching or by injecting the tender spot
Only one of the three minor criteria is needed for helping to establish the diagnosis.2,8
Physical examination of the patient suspected of having myofascial pain syndrome begins with observation of the patient's posture, gait, and other movements. Examination of the limbs commonly shows decreased range of motion and increased pain on passive and active muscle stretching. The skin may have vasomotor changes, such as a blanched or flushed appearance. The examination for trigger points should be guided by history.
The presence of an active or latent trigger point with its referral zone is characteristic for myofascial pain syndrome. The trigger point is usually located within a shortened, tight muscle known as a taut band and when palpated, the patient may experience much pain and jump away from the examiner. This is called the jump sign. Furthermore, reference zones have been described and mapped out in detail in literature.8
Treatment of myofascial pain syndrome should be from a multidisciplinary approach. For example, individuals under stress as well as those with depression may tend to have a greater perception of pain. Counseling for these issues usually leads to a much better prognosis. Other forms of treatment entail the use of trigger point injections, physical or occupational therapy, the spray and stretch technique, ischemic compression, massage therapy, the use of a transcutaneous electrical nerve stimulator, and medications. When multiple modalities are used in concert, pain relief can be substantial and help the patient recover faster.