KINETIC CHARACTERISTICS AND STRESSES OF THE JOINT ON THE LANDING LEG DURING THE LANDING PHASE OF SOFTBALL PITCHING

Abstract

The purpose of this study was by conducting the inverse dynamic method to investigate the joint reaction forces, net muscle joint moments and powers of the ankle, knee and hip during the softball pitch. Four elite softball pitchers experiencing world-class competition were acting as subjects in this study. A Peak high-speed camera (120Hz) and synthesized with a force plate (600Hz) was used to collect the relative parameters of landing leg during pitching. The results indicated that the extensors’ eccentric muscle powers of knee and the flexors’ concentric muscle powers of hip were the important ability for the softball pitching performance. In addition, the greater compressive and shear stresses which around the joint created during the landing phase would put a heavy load on soft tissue, ligament and tendon.