Gait analysis to assess the effects of botulinum toxin type A treatment in cerebral palsy: an open‐label study in 10 children with equinus gait pattern

Abstract

Botulinum toxin type A (BTX‐A) injections induce a dose‐related decrease in muscle tone and increased joint mobility in adults with spasticity and children with cerebral palsy. The aim of this study was to address the question of whether BTX‐A‐related improvements in joint mobility and muscle tone are associated with changes in instrumental gait analysis in children with cerebral palsy. Ten children with cerebral palsy and equinus gait were given a single dose of BTX‐A (5 U BOTOX®/kg body weight per leg) into the gastrocnemius muscles. At follow‐up (mean, 32.6 days post‐injection), a significant (P < 0.05) increase in both passive and active ankle range of motion was observed, together with a decrease in the modified Ashworth score. Instrumental gait analysis showed improvements in ankle and knee kinematics as well as in time‐distance parameters, with a significant increase in step length observed (P < 0.05). Semi‐quantitative analysis of rectified electromyographic (EMG) recordings of the tibialis anterior muscle during gait showed a reduction in EMG activity during the stance phase and an increase in EMG activity during the swing phase. This study demonstrated the benefits of BTX‐A treatment in improving joint mobility and ambulatory function in children with cerebral palsy, and showed that changes in tibial anterior muscle activity as a result of BTX‐A injections into the gastrocnemius muscle can be measured by instrumental gait analysis.