A motion analyzing device includes a myogenic potential measuring unit (20) and a myogenic potential measurement processor (101) to measure the muscle activity of a person who performs a motion and a motion measuring unit (30) and a position measurement processor (102) to measure the body motion. The motion analyzing device also includes an AA muscle co-activation ratio calculating unit (103), a muscle synergy calculating unit (104) and an equilibrium point calculating unit (105) to calculate an equilibrium point of the person and a muscle synergy that is a set of base vectors describing the equilibrium point based on a musculoskeletal model of the person and a constraint condition that the position of the endpoint of the limb matches the position of the equilibrium point in a static situation to keep a posture still under gravity compensation.
MOTION ANALYZING DEVICE, MOTION ANALYZING METHOD, AND RECORDING MEDIUM