Hip Flexibility and Pitching Biomechanics in Adolescent Baseball Pitchers.

CONTEXT: Inadequate hip active range of motion (AROM) may stifle the energy flow through the kinematic chain and decrease pitching performance while increasing the risk for pitcher injury.

OBJECTIVE: To examine the relationship between hip AROM and pitching biomechanics during a fastball pitch in adolescent baseball pitchers.

DESIGN: Cross-sectional study.

SETTING: Biomechanics laboratory.

PATIENTS OR OTHER PARTICIPANTS: A sample of 21 adolescent male baseball pitchers (age = 16.1 ± 0.8 years, height = 183.9 ± 5.2 cm, mass = 77.9 ± 8.3 kg).

MAIN OUTCOME MEASURE(S): Bilateral hip external-rotation (ER), internal-rotation, flexion, abduction, and extension AROM were measured. Three-dimensional biomechanics were assessed as participants threw from an indoor pitching mound to a strike-zone net at regulation distance. Pearson product moment correlation coefficients were used to determine relationships between hip AROM and biomechanical metrics.

RESULTS: Negative correlations were found at foot contact between back-hip ER AROM and torso-rotation angle (r = -0.468, P = .03), back-hip ER AROM and back-hip abduction angle (r = -0.474, P = .03), and back-hip abduction AROM and lead-hip abduction angle (r = -0.458, P = .04). Back-hip extension AROM was positively correlated with increased stride length (r = 0.446, P = .043). Lead-hip abduction AROM was also positively correlated with normalized elbow-varus torque (r = 0.464, P = .03).

CONCLUSIONS: We observed several relationships between hip AROM and biomechanical variables during the pitching motion. These findings support the influence that hip AROM can have on pitching biomechanics. Overall, greater movement at the hips allows the kinematic chain to work at maximal efficiency, increasing the pitch velocity potential.