Abstract
For this study, functional electrical stimulation cycles (FES cycling device) of three kinds were developed for people with disabilities: Four-wheel type, Upright type, and Recumbent type. Each cycling apparatus consists of an FES cycling device unit and a wheelchair, from which the unit attaches and releases easily. The three FES cycling devices have different crankshaft height (crank shaft is the mechanical parts connected to both pedals). Using the apparatus, a pedal sensor, and a three-dimensional motion analysis system (Vicon Motion Systems) to assess voluntary and FES motion, this study evaluated the crankshaft height effects on lower limb joint moments of eight normal subjects. Moreover, using the electromyography setup, the effects of crankshaft height on the EMG values of lower limb muscle were evaluated during voluntary motion. Results indicate that, to realize the cycling motion during voluntary motion, the Four-wheel type and Recumbent type devices needed a greater hip moment and knee moment than the Upright type FES apparatus. However, the Upright type needs less power to realize these motions. Moreover, in FES motion, a somewhat similar tendency to that of voluntary motion was observed. The effect of the crankshaft on the EMG value and EMG timing is considerably large. Especially, EMG timing was found to be affected by subject's pedaling skills.
