The effects of biofeedback therapy by surface electromyography on knee flexion in hemiparetic gait

Abstract

The main objective of this paper was to evaluate the effects of biofeedback therapy by surface electromyography (EMG) on knee flexion in hemiparetic gait. A 58 years old male patient was selected for this study, 11 months after a stroke resulting in left side hemiparesis. Initially, he was subjected to a physical examination and observational gait analysis. Before treatment, the patient was also referred to the movement laboratory of the institution (DMR HC FMUSP). The patient underwent a treatment plan comprising twelve sessions of biofeedback therapy by surface EMG during seven weeks. Right after the end of the therapy the evaluation was repeated. The results showed that gait asymmetry was diminished. Left hip circumduction during swing was decreased. Pelvic obliquity during the whole gait cycle was lower than that of the initial evaluation. Lower values for right hip abduction during initial contact and mid swing were also measured. Left ankle dorsiflexion during the swing phase of gait was increased. Although biofeedback therapy was focused on knee flexion, the gait pattern of the patient showed global improvements. For example, left ankle dorsiflexion during the swing phase was increased while hip circumduction was less apparent. This can probably be explained by the fact that therapy was delivered while the patient was performing a functional activity, gait. These results show that biofeedback therapy by surface EMG seems to be a promising technique in the management of stroke patients.