Pitching Analysis of Body Variables According to Ball Velocity in Amateur Baseball Pitchers Using Gyro Sensor

The purpose of this study was to examine the correlation of ball velocity with body variables in eight amateur baseball pitchers.

Eight amateur baseball pitchers (over-arm pitchers) participated in the study. Body variables were measured using wearable gyro sensors while they were fastball pitching. MVN system can measure kinematic of whole body using inertial sensor. The velocity of the ball was measured using a speed gun. The Pearson correlation coefficient was used to analyze the correlation between pitch velocity and body variables. Significance levels were set at p<0.05.

Ball velocity significantly correlated with the horizontal abduction and abduction of shoulder, trunk rotation angular velocity, stride length (p<0.05). However, no significant correlations were observed in trunk rotation angle (anterior and posterior), foot direction (p>0.05). Greater shoulder horizontal abduction during pitching motion has effective pre-stretch, stored elastic energy and tendons may be utilized during arm cocking and arm acceleration phase of pitch. As increased trunk rotation angular velocity, levels of trunks action develop more advanced and led to increases in energy transfer to the pitching arm. For stride length, it is regarded a not only critical kinematic factor for determine the timing of kinetic chain events but also transitioning energy to the pitching arm from lower extremity. In this study, we can compare with previous studies on pitching motion kinematics. Also previous studies on pitching motion analysis were mainly 3D camera based techniques. In this study, it is meaningful to analyze the pitching motion by using Gyro sensor which complements the limitation that 3D camera technique can have.

Horizontal abduction and abduction of shoulder, trunk rotation angular velocity and stride length should be considered to increase the ball velocity, which is an important ability of the pitcher.