Efficacy of EMG biofeedback in relaxation training: a controlled stury.

Electrical activity in the right elbow flexors has been shown to have a high relationship with a general resting muscular tension factor. It was our purpose to evaluate the efficacy of EMG biofeedback in reducing electrical activity in this muscle group. It was found that EMG voltages were significantly reduced (P less than 0.001) due both to biofeedback treatment and to time of day (construed as a practice and/or restbreak effect). Replication of the experiment without biofeedback and designed to minimize the "restbreak" effect induced by repetitive testing produced no change in the EMG voltages. It was concluded that EMG biofeedback training is effective with the elbow flexor group, and the possibility for training subjects in overall deep relaxation through feedback from this one muscle group is suggested. The importance of the practice effect/restbreak is emphasized.