Stance Stability and EMG Changes in the Ankle Musculature of Hemiparetic Patients Trained on a Moveable Platform

The relationship between training-related improvement in standing balance of hemiparetic patients and changes in the EMG recordings of the medial gastrocnemius (MG) and tibialis anterior (TA) muscles was investigated. Ten hemiparetic patients in the treatment group and six in the control group comprised the subjects. Data from seventeen healthy adults served as normal reference points. The training and testing apparatus was a platform that moved back and forth in a sinusoidal profile. The highest amplitude of movement tolerated by the subject without hand support, called the maximal movement amplitude (MMA), was determined for each patient upon admission and after two, four, and six weeks. At these times, while the patient was moved at his MMA, EMG recordings were taken from the TA and MG muscles. Healthy subjects underwent the same evaluation once. Patients belonging to the treatment group were trained on the platform during fifteen sessions in the two-week intervals between test sessions. Results indicated an increase in the MMA of the treatment group that significantly exceeded values achieved by the control patients. However, this difference was not accompanied by improvement (approximation to normal values) in the EMG variables of the treated patients; nor was there a significant difference between their EMG data and those of the control patients.