Perceived Exertion Is Lower When Using a Functional Electrical Stimulation Neuroprosthesis Compared With an Ankle-Foot Orthosis in Persons With Multiple Sclerosis: A Preliminary Study

OBJECTIVE: This study investigates the direct comparison of energy cost, efficiency, and effort between an ankle-foot orthosis (AFO) and a functional electrical stimulation (FES) device for foot drop in ambulatory patients with multiple sclerosis. DESIGN: Twenty adults (32–74 years old; 55% female) with a diagnosis of multiple sclerosis resulting in foot drop participated in a crossover, counterbalanced preliminary study. Each participant was tested on different days, with each session consisting of a separate walk trial per prosthetic device. Heart rate, oxygen consumption, speed, distance, and self-reported exertion were measured independently for each device walk trial. Repeated-measures analysis of variance with device and visit number as within-participants independent variables were run for the primary outcome variables of perceived exertion, energy, and metabolic efficiency. RESULTS: A significant main effect of device was found for perceived exertion (P = 0.01), with participants reporting decreased exertion levels (Borg Scale) when using the FES compared with the AFO (mean difference, 1.63; 95% confidence interval, 0.49–2.76). Energy and efficiency did not significantly differ by device. CONCLUSION: Results suggest that further investigation of the potential advantages of FES devices over traditional AFO is warranted. TO CLAIM CME CREDITS: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) describe potential differences between an AFO and FES for treatment of foot drop in patients with multiple sclerosis, (2) understand the mechanisms and prevalence of foot drop in patients with multiple sclerosis, and (3) recognize the potential benefit of improved perceived exertion found when using FES for the treatment of foot drop in patients with multiple sclerosis. LEVEL: Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The Association of Academic Physiatrists designates this activity for amaximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.