The Effect of Pitching Biomechanics on the Upper Extremity in Youth and Adolescent Baseball Pitchers

Background: Increased pitch counts have been linked to increased complaints of shoulder and elbow pain in youth baseball pitchers. Improper pitching mechanics have not been shown to adversely affect the upper extremity in youth pitchers. Hypothesis: The correct performance of 5 biomechanical pitching parameters correlates with lower humeral internal rotation torque and elbow valgus load, as well as higher pitching efficiency, in youth and adolescent pitchers. Study Design: Descriptive laboratory study. Methods: In sum, 169 baseball pitchers (aged 9-18) were analyzed using a quantitative motion analysis system and a high-speed video while throwing fastballs. The correct performance of 5 common pitching parameters was compared with each pitcher's age, humeral internal rotation torque, elbow valgus load, and calculated pitching efficiency. Results: Motion analysis correlated with video analysis for all 5 parameters (P < .05). Youth pitchers (aged 9-13) performing 3 or more parameters correctly showed lower humeral internal rotation torque, lower elbow valgus load, and higher pitching efficiency (P < .05). Conclusions: Youth pitchers with better pitching mechanics generate lower humeral internal rotation torque, lower elbow valgus load, and more efficiency than do those with improper mechanics. Proper pitching mechanics may help prevent shoulder and elbow injuries in youth pitchers. Clinical Relevance: The parameters described in this study may be used to improve the pitching mechanics of youth pitchers and possibly reduce shoulder and elbow pain in youth baseball pitchers.