Abstract
The purpose of this study is to introduce the contribution of the joint torques of human to the generation of parameters of human movements. The equation of motion for multi-segment model is obtained from the combination of 1) the equations of motion for individual segments, 2) the equations for constraint condition in which adjacent segments are connected by joint, and 3) the geometric equations for constraint axes of joints such as inversion/eversion axes of the elbow and knee joints. The contribution of the joint torques to the parameters is derived from the dynamic equation. The contribution consists of three parts, such as, total joint torque term, motion dependent term, and gravitational term. The total joint torque term can be, furthermore, divided into each joint axial torque term. The motion dependent term makes significant role for generating end-point speed of linked segment systems, particularly, in high-speed swing motion, such as, tennis serve, baseball pitching and batting motions. The motion dependent term is mainly caused by linear and angular velocities of the segments. Since these velocities are the results of joint torque and external joint force inputs into the system, we have proposed a converting algorithm of the motion dependent term into joint torque terms, external joint force term, and gravity term according to a recurrent equation with respect to the generalized velocity vector of the discrete time system.
