Ground Reaction Force of Baseball Flat Ground Pitching

Abstract

The purpose of this study was to describe the characteristics of the ground reaction force (GRF) of baseball flat ground pitching, and compares the characters with previous research which pitched on pitching mound. Fourteen division I college pitchers participated in this study. A VICON Motion capture system (10 cameras) and two force platforms were used to collect 3-D kinematic data (500Hz) and GRF data (1000Hz). Three successful trials for each subject were analyzed. The result shows the pivot foot anterior/posterior (AP) propulsive force was larger on flat ground, and the leading foot AP force was larger on pitching mound. The other two components GRF were similar in these two ground situations. The three components of GRF had low correlation with ball velocities. Comparing the peak GRF in three components between pitcher with fast and slow ball velocity groups, the fast velocity group produced a larger leading AP braking force. The leading foot AP breaking force may be an important variable for identify the fast and slow pitching ball velocities.