Relationships between hip flexibility and pitching biomechanics in adolescent baseball pitchers
Albiero ML, Kokott W, Dziuk C, Cross JA. Relationships between hip flexibility and pitching biomechanics in adolescent baseball pitchers. J Athl Train. doi: 10.4085/1062-6050-0103.21. Online ahead of print
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 of hip AROM and pitching biomechanics during a fastball pitch in adolescent baseball pitchers.
DESIGN: Cross-Sectional study.
SETTING: Biomechanics laboratory.
PARTICIPANTS: A voluntary sample of 21 adolescent baseball pitchers (16.1 ± 0.8 yrs.; 183.9 ± 5.2 cm; 77.9 ± 8.3 kg). Main Outcome Measure (s): Bilateral hip internal rotation (IR), external rotation (ER), flexion, extension, and abduction 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 correlation coefficients were used to determine correlations between hip AROM and biomechanical metrics.
RESULTS: Statistically significant negative correlations were found at foot contact between back hip ER AROM and back hip abduction angle (p=0.030, r=-0.474), back hip ER AROM and torso rotation angle (p=0.032, r=-0.468),and back hip abduction AROM and lead hip abduction angle (p=0.037, r=-0.458). Back hip extension AROM was positively correlated with increased stride length (p=0.043, r=0.446). Lead hip abduction AROM was also positively correlated with normalized elbow varus torque (p=0.034, r=0.464).
CONCLUSIONS: There were several relationships between hip AROM and biomechanical variables during the pitching motion. The findings support the influence hip AROM can have on pitching biomechanics. Overall, greater movement at the hips allows for the kinematic chain to work at its maximal efficiency, increasing pitch velocity potential.