Human gait control suggested by the evaluation of the fluctuation of synergy

A high correlation among the motion of joints and muscles is observed when human walking. A group of the correlated motion is called synergy and the contribution of synergy on the locomotion control has been discussed. This research consider the motion pattern obtained by the singular value decomposition of joint motion as synergy, and consider the mode control using synergy for human locomotion. Several current researches evaluate the fluctuation of motion and search the variable with low fluctuation as control variable (UCM analysis), thus the evaluation of fluctuation will reveal whether synergy is control variable or not. Then we calculate the fluctuation of the whole motion and several principal motion such as COM, head and hip, and compare them with the fluctuation of synergy. As the result, the fluctuation of the synergy is shown to be relatively small, thus human locomotion is possible to be controlled using synergy.