Evaluation of Pedaling Skill Based on Muscle Synergy in Lower Extremities during Pedaling Exercise

Abstract

The central nervous system does not control multiple muscles independently, whereas it manipulates a musculoskeletal system with redundant degrees of freedom. In specific, muscle synergy that represents muscle coordination realizes an advanced motion control of human body. In the pedaling exercise, the coordinated muscle activity between lower extremities is key for high-efficient exercise when cyclists use binding pedals which fixes both pedals and shoes via cleats. Under the present circumstances, few reports focused on the muscle coordination of both legs. Thus, the relationship between the coordination of both legs and the mechanism of pedaling has not yet been clarified. In this study, we investigated the muscle synergy hidden in lower extremities by measuring surface electromyography and crank rotation angle during pedaling exercise under different mechanical constraints. In the results, this study confirmed the muscle cooperativeness formed by both the left and right leg during pedaling. Besides, the muscle cooperativeness had different roles on both legs because this coordination was asymmetrical regardless of the changes in cadence and workload. The muscle coordination formed by both legs was considered to be an evaluation index that could explain how the left and right legs were coordinated for effective pedaling with binding pedals. K E Y W O R D Sbinding pedal, muscle synergy, pedaling exercise, racing bicycle, surface electromyography 10