KINEMATIC ANALYSIS OF BASEBALL BATTING MOTION WHEN BATTING PITCHES WITH VARYING VELOCITIES

Abstract

The purpose of this study was to identify effect of moving the center of gravity of the body and rotating the torso when batting pitches with varying velocity. The subjects were 10 experienced university baseball player. The subjects batted toward the center field, both fastballs and slowballs, aimed near the center of the strike zone from a pitching machine. Data were collected using a three dimensional automatic motion analysis system (Vicon MX). The rotation angle of the torso and displacement of the center of gravity were computed. Due to differences in the shoulder rotation from the latter half of stepping leg touchdown through impact, we believe that the motion is adapted to pitch differences starting from the latter half of stepping leg touchdown. Comparing the shift in the center of gravity of the body during fastballs and slowballs, the forward motion and downward sinking of the center of gravity were significantly larger for slowballs.