THE EFFECT OF MUSCLE SETTING ON KINETICS OF UPPER EXTREMITY IN A BASEBALL PITCHING MODELING: A CASE STUDY

Abstract

The purpose of the current research was to calculate the joint torques and joint reaction forces of the upper extremity with and without muscles in the AnyBody Modeling System in baseball pitching in order to investigate the importance of including muscles on the joint torques and joint reaction forces. We also compare our results to previous studies obtained by inverse dynamics without muscles. One elite college baseball pitcher volunteered to be the participant. A motion analysis system was used to collect kinematic data for the AnyBody Modeling System in order to derive the joint torques and joint reaction forces. The results showed that joint torques of our study with muscles included were similar between previous and current researches. However, the joint reaction forces obtained with muscles included were significantly higher in the current model than the previously reported models and the current model without muscles. This suggests that the disregarding muscles underestimate the joint reaction forces and the risk of injury in joint contact areas.