A comparison of the initial orthotic effects of functional electrical stimulation and ankle-foot orthoses on the speed and oxygen cost of gait in multiple sclerosis

Foot drop affects walking in people with multiple sclerosis (pwMS). This study compares the initial orthotic effects of two treatments for foot drop: ankle-foot orthoses (AFO) and functional electrical stimulation (FES), on the speed and oxygen cost of walking in MS. Method and materials: Seventy-eight pwMS were randomised to receive AFO or FES (ODFS PACE (OML, Salisbury, UK)). Participants completed the 25-ft walk test (25ftWT) and 5-min self-selected walk test (5minSSWT), from which oxygen cost was determined, with and without their device. Between-, within- and sub-group analyses (based on baseline walking speed of <0.8 m/s (slow) or ≥0.8 m/s (fast)) were undertaken. Results: No significant differences between baseline measures were observed. The AFO group walked significantly slower than the FES group (5minSSWT, p = 0.037, 0.11 m/s). The AFO group walked significantly slower with than without AFO (25ftWT, p = 0.037), particularly in the fast-walking group ( p = 0.011). The slow-walking FES group walked significantly faster with FES than without (25ftWT; p = 0.029, 5minSSWT; p = 0.037). There were no differences in the fast-walking FES group or in the oxygen cost for either device. Conclusion: AFO reduced walking speed, particularly in fast walkers. FES increased walking speed in slow, but not fast walkers.