Effect of Repetitive Pitching on the Control of Lower Extremity Joints and Center of Mass in Collegiate Baseball Pitchers

Background: Repetitive motion can alter joint angles and subsequently affect the control of the center of mass (CoM). While the CoM has been studied as a fatigue indicator in various sports, the control of the whole-body CoM during repetitive pitching in baseball pitchers has not been examined. This study aimed to investigate changes in lower-extremity joint angles and CoM control in collegiate baseball pitchers after repetitive pitching.Hypothesis: Baseball pitchers would exhibit significant increase in lower-extremity flexion angles, CoM position, and CoM variability after repetitive pitching.Study Design: Descriptive laboratory study.Level of Evidence: Level 3.Methods: A total of 23 pitchers from the Collegiate Baseball League were recruited. A motion analysis system was employed to assess lower-extremity joint angles and CoM position during the simulated game, while pitching accuracy and velocity were also recorded.Results: The results revealed a significant forward and downward shift in CoM position (P< 0.05), along with increased CoM variability in all directions (P< 0.05) after the simulated game. Furthermore, there was a significant increase in flexion angles of the knee and hip (P< 0.05); however, pitching velocity and accuracy did not demonstrate significant changes.Conclusion: Repetitive pitching leads to kinematic changes that should be monitored to prevent sports injuries.Clinical Relevance: Baseball pitchers have the ability to modify the control of their CoM and angles of their lower-extremity joints to sustain their pitching performance. It is crucial to monitor compensatory strategies closely to avoid shoulder and elbow injuries among these pitchers.