Myofascial Pain:

Myofascial pain [MFP] is a common cause of persistent regional pain characterized by local pain, associated muscle tenderness, and slight decrease in range of motion. Although many definitions exist for MFP, little research has been done on the reliability and validity of proposed diagnostic criteria for this disorder. In this series of studies, operational definitions were developed for the most common signs of MFP and then tested for inter- and intra-rater reliability. This standardized examination was then applied to 30 MFP patients and 30 normal subjects by an examiner blinded to the status of the subject. Discriminant analysis was then used to evaluate the relative predictive value of each individual item and to generate diagnostic criteria. The scope of tenderness [percent of specific muscle sites tender] was the most predictive sign with adequate reliability. The sensitivity and specificity was 93.5% and 80.6%, respectively with diagnostic at 28% or more muscle sites tender.