Pilot Study: Evaluation of the Effect of Functional Electrical Stimulation Cycling on Muscle Metabolism in Nonambulatory People With Multiple Sclerosis

Objective: To investigate the changes in muscle oxygen consumption (m(V) over dotO(2)) using near-infrared spectroscopy (NIRS) after 4 weeks of training with functional electrical stimulation (FES) cycling in nonambulatory people with multiple sclerosis (MS). Design: Four-week before-after trial to assess changes in (V) over dotO(2) after an FES cycling intervention. Setting: Rehabilitation hospital. Participants: People (N=8; 7 men, 1 women) from a volunteer/referred sample with moderate to severe MS (Expanded Disability Status Scale score>6.0). Intervention: Participants cycled 30 minutes per session, 3d/wk for 4 weeks or a total of 12 sessions. Main Outcome Measures: (V) over dotO(2) of the right vastus lateralis muscle was measured with NIRS before and within 1 week after the intervention. Six bouts of 15-second electrical stimulation increasing from 2 to 7Hz were used to activate the muscle. (V) over dotO(2) was assessed by analyzing the slope of the NIRS oxygen signal during a 10-second arterial occlusion after each electrical stimulation bout. Results: Significant FES training by electrical stimulation frequency level interaction was observed (P=.031), with an average increase in (V) over dotO(2) of 47% across frequencies with a main effect of training (P=.047). Conclusions: FES cycling for 4 weeks improved (V) over dotO(2), suggesting that FES cycling is a potential therapy for improving muscle health in people with MS who are nonambulatory. Archives of Physical Medicine and Rehabilitation 2015;96:627-32 (C) 2015 by the American Congress of Rehabilitation Medicine