The Effects of Muscle Activity and Spatio Temporal Parameters after Botulinum Treatment for Hemiparetic Gait

Abstract

Purpose: The purpose of this study was to investigate the impact of botulinum toxin type A (BoNT-A) administered for lower limb spasticity on the gaits of hemiplegic stroke patients.

Methods: Subjects comprised 15 chronic stroke patients at least 6 months after their stroke. A total of 300 units of BoNT-A was injected into the gastrocnemius, soleus, tibialis posterior, flexor digitorum longus and/or flexor hallucis longus according to each patient’s condition. Each subject was asked to walk 10 m, and lower limb electromyography (EMG), gait velocity, gait cycle, and stride length were measured before and 2 weeks after BoNT-A injections. For EMG analysis, the gait cycle was divided into phases (i.e., loading response, single support, pre-swing, and swing), and the average amplitude and coactivation index of each phase were calculated.

Results: After BoNT-A treatment, there was a significant increase in the muscle activity of tibialis anterior (97.3%–111.0%), significant decrease in the muscle activity of soleus (176.3%–142.4%), and significant increase in the coactivation index of rectus femoris and biceps femoris (112.9%–129.5%) during the loading-response phase. There were no significant differences in spatial or temporal parameters before and after treatment.

Conclusion: BoNT-A treatment changed soleus muscle activity during gait, which resulted in changes in the muscle activity of tibialis anterior and the coactivation of knee joint. However, the lack of change in spatial and temporal parameters indicated that walking ability was not improved by BoNT-A treatment alone. Therefore, while BoNT-A treatment resulted in changes in lower limb muscle activity, it is unlikely that it alone can improve spatial and temporal parameters.