Feasibility of Home-Based Functional Electrical Stimulation Cycling for Persons with Multiple Sclerosis with Mobility Disability

Background: There are several reported benefits of exercise training for individuals with multiple sclerosis (MS); however, these benefits have largely been established under supervised training conditions. Supervised exercise settings present substantial barriers to exercise participation, particularly for those with mobility impairment. Functional electrical stimulation (FES) cycling is a specialized rehabilitation modality that is approved for home-based use and might enhance the capacity for adaptations to exercise in persons with ambulatory impairments. Delivery of exercise within the home setting can be challenging. As such, the feasibility of such interventions should first be established to appropriately design future efficacy trials.

Objectives: To examine the feasibility of home-based FES cycling exercise for individuals with MS with mobility impairment to inform a future Phase II randomized clinical trial.

Methods: Four participants with MS (EDSS=6.0-6.5) were recruited to partake in 12-weeks (3x/week) of home-based (i.e., self-administered) FES cycling exercise. Feasibility metrics included participant retention, adherence, safety (i.e., adverse events, AE), satisfaction, and treatment efficacy, assessed as mobility and physiological fitness. The efficacy of FES cycling on mobility and physiological fitness were calculated as effect sizes based on Cohen’s d. 

Results: Three out of four participants (i.e., 75% retention) completed the intervention with a mean adherence rate of 96.3%. One participant reported two separate mild (Grade 1) AEs, including muscular pain and skin irritation, which were likely related to trial participation. Participants reported being “Very-to-Extremely Satisfied” with the overall exercise program and the equipment. Participants reported that using the cycle at home was ‘Not Challenging at All’ or ‘Slightly Challenging’, and all participants reported being ‘Completely Independent’ in using the cycle at home. There were small, positive effects of FES cycling on walking speed (d=0.24), peak power output (d=0.25), and knee flexor strength (d=0.41).

 Conclusions: Compared to previous literature, the current study reported high intervention adherence, few adverse events, and general participant satisfaction. There was a slightly higher rate of dropout which can likely be explained by the higher disability level of the sample. Overall, these metrics will be valuable to inform future trials of home-based, FES cycling exercise.