RELATIONSHIP BETWEEN POOR MECHANICS AND CHANCE OF INJURY

Improper mechanics are believed to increase the stress on the throwing shoulder and elbow, resulting in increased chance of injury. In a study by ASMI, eight mechanisms of improper kinematics that lead to increased loads were proposed.

To investigate these hypotheses, 72 pitchers were studied. Four kinematic parameters correlated with increased shoulder force: placement of the lead foot toward the open side, pointing of the lead toe toward the open side, and increased or decreased shoulder rotation at the instant of front foot contact.

Two kinematic parameters correlated with increased elbow force: increased shoulder rotation at the instant of front foot contact, and increased shoulder horizontal adduction. Although these correlations were statistically significant, the loading increase from any individual mechanism was minimal. The presence of multiple improper mechanisms may increase loading further. Cumulative effect of increased loads from repetitive pitching may result in increased injury risk.