Utilizing EMG Biofeedback To Modify Cortical Contributions To Postural Control

Electromyography Biofeedback (EMG-BF) is a clinical tool used to enhance patient awareness of muscular functions in real time. When used with rehabilitation exercises, it is believed that EMG-BF can enhance neural plasticity in postural control muscles. We measured peripheral and cortical excitability before and after a balance intervention with or without EMG-BF intervention. Nineteen healthy men and women between the ages of 19-24 participated in this study. The Hoffmann reflex (H-Reflex) and motor evoked potentials (MEP) were elicited for three postural control muscles: tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) with electrical and transcranial magnetic stimulation before and after two sessions of 30-minutes of balance training using the Biodex Balance System. Reflexive excitability and MEP size was compared across muscles, intensity, time, and groups. Results indicated that EMG-BF eliminated differences in reflexive excitability between PL and SOL, potentially causing the PL to behave as a postural muscle. Cortical excitability to the SOL decreased in the group that received EMG-BF, but not for the TA and PL. These findings potentially indicate that balance training with EMG-BF has the effect of inhibiting the SOL, which could be clinically useful for treatment of lower extremity dystonia.