The Effect of Functional Electrical Stimulation (FES) on the Energy Expenditure of Overground Walking in People with Multiple Sclerosis
Paul L1, Young S2, Rafferty D2, Miller L3, Mattison P3, McFadyen A4 1 Nursing and Health Care – Faculty of Medicine, University of Glasgow, 2 School of Health and Social Care, Glasgow Caledonian University, 3 MS Service, NHS Ayrshire and Arran, 4School of Engineering and Computing, Glasgow Caledonian University
Douglas Grant rehabilitation unit, Ayrshire Central Hospital, Kilwinning Rd, Irvine, KA127EE
Purpose/relevance Functional Electrical Stimulation (FES) is used clinically in the management of drop foot in neurological conditions. The study investigated the effects of FES on gait speed and energy expenditure, in people with Multiple Sclerosis (pwMS). Subjects/ methods Twelve pwMS and 12 healthy matched controls were recruited. The subjects walked at their own preferred walking speed (PWS) for five minutes around a 10m elliptical course. PwMS walked with and without using their FES and control subjects also completed the protocol walking at the same PWS of their matched MS subject. A COSMED K4b2 gas analysis system measured the percentage of expired oxygen. Ethics approval was granted by NHS Ayrshire and Arran ethics committee. Analysis Paired t tests were used to investigate the differences between MS subjects with and without FES and for controls at their PWS and matched speeds of pwMS. A Bonferroni correction was applied and the alpha level set at 0.025. Results Wearing FES lead to a significant improvement in walking speed (0.49m•s-1 and 0.43ms-1 with and without their FES respectively; P<0.001) and a significant reduction in the energy expenditure of walking (0.41 mL•min-1•kg-1•m-1 and 0.46 mL•min-1•kg-1•m-1 with and without FES respectively; P=0.017) in pwMS. The speed of walking, oxygen uptake and energy expenditure were significantly different between pwMS and controls both at preferred and matched speeds. Discussion/Conclusion Whilst pwMS exhibit a higher energy cost of walking FES offers an orthotic benefit to pwMS and should be considered as a possible treatment option. Further research on the functional benefits of FES is required.
References
Paul L, Young S, Rafferty D, Miller L, Mattison P, McFadyen A (2008) The effect of functional electrical stimulation on the physiological cost of gait in people with multiple sclerosis. Multiple Sclerosis, 14, 954–961.