Evaluation of hip internal and external rotation range of motion as an injury risk factor for hip, abdominal and groin injuries in professional baseball players

Normal hip range of motion (ROM) is essential in running and transfer of energy from lower to upper extremities during overhead throwing. Dysfunctional hip ROM may alter lower extremity kinematics and predispose athletes to hip and groin injuries. The purpose of this study is characterize hip internal/external ROM (Arc) and its effect on the risk of hip, hamstring, and groin injuries in professional baseball players. Bilateral hip internal and external ROM was measured on all baseball players (N=201) in one professional organization (major and minor league) during spring training. Players were organized according to their respective positions. All injuries were documented prospectively for an entire MLB season (2010 to 2011). Data was analyzed according to position and injuries during the season. Total number of players (N=201) with an average age of 24±3.6 (range=17-37). Both pitchers (N=93) and catchers (N=22) had significantly decreased mean hip internal rotation and overall hip arc of motion compared to the positional players (N=86). Players with hip, groin, and hamstring injury also had decreased hip rotation arc when compared to the normal group. Overall, there is a correlation between decreased hip internal rotation and total arc of motion with hip, hamstring, and groin injuries