Effects of EMG Biofeedback Training on Ankle Control and Gait in Hemiparetic Patients

Abstract

Background and Purpose. The objectives of this study were to investigate the effect of a combined treatment program of therapeutic exercises and EMG biofeedback (EMGBF) on gait, ankle dorsiflexion range of motion (ROM), and motor unit recruitment of the tibialis anterior (TA) muscles, and to reveal the influence of body position on the level of motor unit recruitment. Subjects. Ten ambulatory hemiparetic patients (onset duration＞4 months), aged 29 to 67 years (mean=53, SD=12), participated in the study. Methods. Subjects received an EMGEF training in sitting position targeted on the tibialis anterior muscles, in addition to their regular therapeutic exercise program during the experimental period. The ROM of the affected ankle dorsiflexion, the time and the number of steps (STEP) taken to ambulate a walkway, and the EMG (integrated and peak) activity of the TA in sitting and standing were evaluated before and after one month's treatment. Results. Significant improvement was found in the TA EMG after the training. The difference in the level of EMG between sitting and standing, and changes in the gait variables and ankle range of motion were nonsignificant. The ankle range of motion was significantly correlated with the gait variables and the TA EMG in sitting. The EMG in the sitting position is also correlated with STEP. Discussion and Conclusion. The combined treatment of therapeutic exercise and EMGBF is effective in enhancing the level of motor unit recruitment in the TA and the subjects learned to control this muscle in both sitting and standing. Thus, transfer in motor learning is possible after EMGBF training. However, the subjects failed to gain significant improvement in the gait variables and the ankle ROM, indicating that the ability to control individual muscle does not necessarily accompanied by better functional performance. Functional training following EMGBF training is recommended in order to maximize functional gain.