QUANTITATIVE EVALATION OF DEXTERITY BY MODELING OF JOINT TORQUE

Abstract

The aim of this study is to quantitatively evaluate the stretch reflex on athletic motions. In this study, we regard stretch reflex as an index of dexterity because dexterous motions effectively utilize the stretch reflex by relaxing the stiffness of articulations. Subjects were one skilled and one unskilled. They performed power clean that is a typical strength training motion. We measured trajectories of joints by using the motion capture system, numerically filtered, differentiated, and calculated the articulation torques. In order to evaluate the strength of stretch reflex, we employ a time series curve fitting method in the proposed torque model that includes a term caused by stretch reflex. The results indicate that the skilleds’ strength of stretch reflex shows large value, compared to the unskilled’s one. This suggests that the proposed torque model and the analytic method allow us to quantitatively measure dexterity.