抄録
Many badminton players have ruptured their Achilles tendon in scissors jump. In this study, the dynamic model of leg joint was constituted and motion analysis was carried to find the forces in tendons and moments in joints. This dynamic model consists of thigh, tibia and foot segments and knee and ankle joints modeled by rigid rods and springs and dashpots. This analytical method was verified by experiment of jumping on a force plate. Furthermore the method to estimate the forces applied to tendons was proposed. The relationships between the forces and motion were investigated. The force applied to Achilles tendon can be reduced by 20 % by flexing the knee, 30 % by changing the direction of toe and 10 % by locating the weight of body on the heel side.
