Effect of Peroneal Electrical Stimulation Versus an Ankle-Foot Orthosis on Obstacle Avoidance Ability in People With Stroke-Related Foot Drop

Abstract

Walking ability of people with foot drop in the chronic phase after stroke is better with functional electrical stimulation (FES) of the peroneal nerve than without an orthotic device. However, the literature is not conclusive on whether peroneal FES also is better than an ankle-foot orthosis (AFO) in this regard. This study aimed to identify potential benefits of peroneal FES over an AFO with respect to the ability to negotiate a sudden obstacle. The study design was a within-subject comparison between FES and AFO using repeated measures. Twenty-four community-dwelling people with stroke (mean age=52.6 years, SD=12.7) who regularly used a polypropylene AFO were fitted with a transcutaneous FES device. The participants' obstacle avoidance ability was tested after 2 and 8 weeks. They had to avoid 30 obstacles that were suddenly dropped on a treadmill in front of the affected leg while walking with either FES or an AFO. The obstacle avoidance success rates were determined. Success rates were higher with FES than with an AFO, especially after adjustment for individual leg muscle strength. Participants with relatively low muscle strength (Motricity Index score <64) were most likely to benefit from FES regarding obstacle avoidance ability. Further work is needed to determine whether the results may be generalized to other groups of people with stroke. Peroneal FES seems to be superior to an AFO with regard to obstacle avoidance ability in community-dwelling people with stroke. The observed gains in obstacle avoidance ability appear to be clinically most relevant in the people with relatively low leg muscle strength.