The Evaluation of Electromyography Biofeedback on Proprioception and Balance in Healthy Young Athletes

Introduction: We evaluated the effect of electromyography biofeedback on proprioception and functional balance in healthy young athletes. Materials and Methods: In this clinical trial, 24 athletes were randomly divided into two study (n=12) and control (n=12) groups. The study group received rehabilitation exercises, including one-foot standing, squatted standing, and isometric contraction of quadriceps muscle at different knee angles, including 30, 45, and 90 degrees of knee flexion along with electromyography biofeedback. The control group received only rehabilitation exercises without electromyography biofeedback. Exercises were performed by both groups for a 4-week period in three sessions per week. Functional balance and proprioception before and after exercises were measured using the star excursion balance test and a system consisting of digital photography non-reflective markers, respectively. The data of the center of pressure and time of vertical ground reaction force using a force plate was also collected to evaluate static balance and dynamic balance, respectively. Results: The absolute error in knee joint reconstruction for 30° (P=0.005),  45°  (P=0.001),  and 90° (P=0.033) angles significantly decreased after the intervention in the study group compared to the control group. Star excursion balance test scores in all directions did not show any significant differences between the two groups (P>0.05), except for the anterior-lateral direction (P=0.03). Moreover, all variables related to static and dynamic balance did not show a significant difference between two the groups after the interventions (P>0.05). Conclusion: The electromyography biofeedback intervention can probably be used as a rehabilitation protocol in recovering and healing proprioception injuries resulting from sports injuries.