Effects of Functional Electrical Stimulation Cycling Combined With Arm Cranking Exercise on Cardiorespiratory Fitness in People With Central Nervous System Disorders: A Systematic Review and Meta-analysis.

Objective: To examine the evidence regarding the potential of hybrid functional electrical stimulation (FES) cycling for improving cardiorespiratory fitness for people with a mobility disability related to a central nervous system (CNS) disorder.

Data Sources: Nine electronic databases: MEDLINE, EMBASE, Web of Science, CINAHL, PsycInfo, SPORTDiscus, Pedro, Cochrane, and Scopus, were searched from inception until October 2022.

Study Selection: Search terms included multiple sclerosis, spinal cord injury (SCI), stroke, Parkinson's disease, cerebral palsy, synonyms of FES cycling, arm crank ergometry (ACE) or hybrid exercise, and V̇o. All experimental studies, including randomized controlled trials that included an outcome measure related to peak or sub-maximal V̇o were eligible.

Data Extraction: From a total of 280 articles, 13 were studies included. The Downs and Black Checklist was used to assess study quality. Random effects (Hedges' g) meta-analyses were undertaken to determine whether there were differences in V̇o during acute bouts of hybrid FES cycling vs other modes of exercise and changes resulting from longitudinal training.

Data Synthesis: During acute bouts of exercise, hybrid FES cycling was moderately more effective than ACE (effect size [ES] of 0.59 (95% CI 0.15-1.02, P=.008) in increasing V̇o from rest. There was a large effect on the increase of V̇o from rest for hybrid FES cycling compared with FES cycling (ES of 2.36 [95% CI 0.83-3.40, P=.003]). Longitudinal training with hybrid FES cycling showed a significant improvement in V̇o from pre to post intervention with a large, pooled ES of 0.83 (95% CI 0.24-1.41, P=.006).

Conclusions: Hybrid FES cycling produced higher V̇o compared with ACE or FES cycling during acute bouts of exercise. Hybrid FES cycling can improve cardiorespiratory fitness in people with SCI. Additionally, there is emerging evidence that hybrid FES cycling might increase aerobic fitness in people with mobility disability related to CNS disorders.