DEFINITlON OF MYOFASCIAL PAIN SYNDROME AND THERAPEUTIC PROTOCOL

by
Chang-Zern Hong M.D.
Clinical Director,
Dept. Physical Medicine and Rehabilitation, UNIVERSITY OF CALIFORNIA IRVINE, and KATELLA PAIN CONTROL MEDICAL CLINIC
PHONE: 714-634-5629 or 714-772-7272

The MYOFASCIAL PAIN SYNDROME is now a well-accepted disease entity as one can find this term in the International Classification of Diseases (ICD.9.CM: 729.1). It is usually caused by trauma (such as strain, sprain, or contusion), inflammatory diseases (such as tendinitis, bursitis, synovitis or arthritis), or spinal discogenic diseases (such as disc herniation or even just only disc bulging). It can also be caused by the cumulative effect of long standing repetitive minor trauma or long standing muscle tension due to poor posture, occupational diseases (such as that requiring repetitive use of certain muscle groups), or emotional stress.

Certain bands of the muscle fibers respond to the trauma or abnormal stress by tightening. This impairs local circulation leading to the accumulation of metabolic waste products and further tightening occurs. This, then, becomes a vicious cycle.

The hyperirritable spots within the taut bands of muscle fibers are called TRIGGER POINTS that are painful on compression and that can cause characteristic referred pain, tenderness, and autonomic phenomena.

Many medical conditions (PERPETUATING FACTORS), including mechanical stress, nutritional inadequacies, metabolic and endocrine inadequacies, chronic infections, or psychological factors may perpetuate myofascial pain syndrome or may aggravate the severity of myofascial pain syndrome.

The DIAGNOSIS of myofascial pain syndrome is based on patients symptoms and objective findings including:

  1. Consistent and characteristic referred pain pattern
  2. Focal twitch responses in the taut bands of involved muscles
  3. Limited range of motion
  4. Weakness without atrophy
The principal TREATMENT of myofascial pain syndrome is stretching and relaxation of tight muscles to break the vicious cycle. This can usually be done with spray and stretch technique (with Flouri-methane) and/or with deep pressure soft tissue massage, combined with thermotherapy with hydrocollator hot pack (superficial moist heat) and/or ultrasound (deep heat). Elimination of perpetuating factors (if any) is also very important to avoid frequent recurrence.

Instruction in, and consistent performance of a home program is also required to facilitate recovery. The home programs usually include self-stretching techniques, maintaining proper postures and therapeutic exercises. Repeated stretching is usually required if the lesion is chronic in nature.

Trigger point injections with 0.5% Lidocaine at an interval of once per week are necessary if physical therapy programs cannot effectively relieve the chronic trigger points. The trigger point injection is a special technique requiring high skill. It is quite different from tender point injection which can be done by any physician. The taut band should be injected at a certain degree of angle with a certain speed of needle movement to obtain an optimal effect. The total number required for injection depends on the nature and the chronicity of the disease, but the frequency for injection is usually reduced gradually.

. . REFERENCES:

  1. Travell and Simons: Myofascial Pain Syndrome and Dysfunction - The Trigger Point Manual Williams and Wilkins, 1983;
  2. Simons: Myofascial Pain Syndrome due to Trigger Points; International Rehabilitation Medicine Association Monograph Series No. 1, November, 1987. pp. l-39.
  3. Simons: Myofascial Pain Syndrome; in CURRENT THERAPY OF PAIN, B.C. Decker Inc , 1989. pp. 251-266.
  4. Simons and Travell: Myofascial Pain Syndromes; in TEXTBOOK OF PAIN, (Ed. by: Wall and Melzack) Chapter 25, 1990 pp.368-385.
  5. Simons: Muscular Pain Syndromes; in ADVANCES IN PAIN RESEARCH AND THERAPY, VOL.17, Chapter 1., 1990 pp.1-41