Regional soft tissue pains: alias myofascial pain?

This chapter deals with four main questions: what is the evidence that 'myofascial pain' syndromes exist?; what is the evidence that the myofascial pain concept is clinically useful?; what is the evidence that managing patients in terms of the myofascial pain diagnosis confers benefits?; and what is the evidence-based management of myofascial pain? The purpose of a diagnosis is to provide boundaries around subgroups of illness in a population since each subgroup presumably has a different mechanism, natural history, prognosis, course and response to treatment. The current literature is divided in its conceptual approach to the problem of regional musculoskeletal pain. Some authors regard myofascial pain as being distinct from regional musculoskeletal pain while others regard these as synonymous. A postulated theory of the pathophysiology of myofascial pain is discussed. This contrasts with a view that regional myofascial pain represents a non-specific localized pain arising from multiple regional, systemic and psychosocial factors. In order to consider myofascial pain as a distinct diagnosis, it would be necessary to resolve reliability issues in the identification of its critical diagnostic features. Beyond reliability issues, there are also problems of sensitivity and specificity--i.e. of the patient population that it identifies--which must be resolved if controlled trials are to be conducted. The clinical usefulness of the myofascial pain diagnosis is considered with regard to what is believed about the course of healing, the determinants of disability, the course of regional versus widespread musculoskeletal pain, the relationship of musculoskeletal injury to pain, and the evidence-based management of musculoskeletal pain. An epidemiological perspective is proposed with regard to regional musculoskeletal pain. This allows for the identification of operationally defined strata of regional musculoskeletal pain and permits studies in course, prognosis and treatment, even though some conceptual issues such as the 'myofascial pain diagnosis' remain to be clarified.