KINEMATIC COMPARISONS OF DIFFERENT PITCH VELOCITY GROUPS IN BASEBALL USING MOTION MODEL METHOD

  • Keizo Takahashi
  • Norihisa Fujii
  • Michiyoshi Ae
Keywords: motion model, kinematics, pitching, baseball

Abstract

The purpose of this study was to compare kinematic parameters of the pitching motion between different pitch velocity groups. Twenty - two varsity baseball players (19 pitchers and 3 fielders) volunteered to participate in this study as subjects. Throwing motions were videotaped with two high- peed (250 fps) VTR cameras. A 15 body segment model of the pitcher was constructed from 26 body segment endpoints reconstructed with the DLT technique. The motion model was constructed for each group to compare the kinematic parameters. High-pitch velocity group had a sequence of appropriate sequence of the joint and segment movement, i.e., hip rotation, shoulder rotation, shoulder horizontal adduction, and elbow extension, while low-pitch velocity group had done the shoulder rotation and elbow extension simultaneously.