Visiting Researcher: Takuma Yukimura Article List>> This study proposes a method of simulating the movement of the human body by using a musculoskeletal system model. First, a musculoskeletal model of the body’s upper and lower halves was constructed after considering the positions of muscle attachment presented in the studies of Delp and van der Helm. In order to simulate the movement, the generalized coordinates were used as variables, and the muscular power was evaluated through the movements by using Hill’s model. By optimizing the objective function based on the muscular power, walking and kicking movements were simulated. The maximum value of the muscular power of each muscle and the lactic acid content were altered so that the change in movement with the increase in muscular power and with the increase in the fatigue level could be calculated in each case. Figures 1 (a) to (c) show the development of fatigue in the human body due to repeated kicking. Fig.1 When calculating the walking movement, understanding the mechanism by which the body is maintained in equilibrium during walking is important. Therefore, based on robotic researches, this study proposed a calculation model that analytically derives the barycentric orbit and angular momentum around the center of gravity for the walking movement of a human body, by which the generalized coordinates by using inverse kinematics can be calculated. In addition, using our model, which analytically derives the momentum and barycentric orbit during walking, this study proposed a method of simulating the movement of a human body in continuous motion while maintaining equilibrium when subjected to a large external force. Figure 2 shows an example of the movement to restore the balance when a human body is pushed forcefully from behind. Fig. 2 This study can be applied to various fields such as medicine, physical therapy, and animation.