Changes in Youth Baseball Pitching Biomechanics: A 7-Year Longitudinal Study:

Background:Pitching biomechanics are associated with performance and risk of injury in baseball. Previous studies have identified biomechanical differences between youth and adult pitchers but have not investigated changes within individual young pitchers as they mature.Hypothesis:Pitching kinematics and kinetics will change significantly during a youth pitcher’s career.Study Design:Descriptive laboratory study.Methods:Pitching biomechanics were captured in an indoor laboratory with a 12-camera, 240-Hz motion analysis system for 51 youth pitchers who were in their first season of organized baseball with pitching. Each participant was retested annually for the next 6 years or until he was no longer pitching. Thirty kinematic and kinetic parameters were computed and averaged for 10 fastballs thrown by each player. Data were statistically analyzed for the 35 participants who were tested at least 3 times. Within-participant changes for each kinematic and kinetic parameter were tested by use of a mixed linear ...