title: Electromyographic (EMG) feedback in chronic musculoskeletal pain: a controlled trial.
abstract: The literature regarding the application of EMG feedback training in musculoskeletal pain disorders is reviewed. A within-subject control trial of EMG feedback using a counterbalanced design in patients with chronic musculoskeletal pain is reported here. Eighteen subjects (12 females and 6 males) were studied in terms of subjective reports of pain and EMG activity measurement under standardised conditions. Both EMG feedback and a control condition were active in reducing subjective pain levels, which increased during a waiting list conditions in certain sequences. EMG activity declined during both EMG feedback and control conditions but only EMG feedback resulted in an orderly reduction in EMG baseline measurements with a highly significant linear trend when presented before the control condition in sequence. A significant correlation between subjective pain levels and surface EMG activity was found. These data suggest that EMG feedback is superior to a control condition in training muscle relaxation but not in reducing subjective pain levels despite a high correlation between these two parameters. Non-specific factors may well affect pain scores and further research is required before the specific biofeedback training effect can be accepted as superior to its non-specific effects in reducing subjective pain.
mesh_terms: D000293:Adolescent; D000328:Adult; D001676:Biofeedback, Psychology; D002986:Clinical Trials as Topic; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000503:physiopathology; D010146:Pain / Q000503:physiopathology; D059408:Pain Management; D012064:Relaxation Therapy