Effects of Sport Specialization on Pitching Biomechanics in Adolescent Baseball Pitchers

Adolescent sport culture is moving away from multisport participation, emphasizing sport specialization for improved skill development despite concern of injury. This study examined biomechanical differences among low-, moderate-, and high-level specialized pitchers.

Kinetics, kinematics, and peak velocities will vary with specialization level.

Descriptive laboratory study.

Level 3.

Adolescent male baseball pitchers' (N = 46) pain, injury, baseball exposure history, and pitching biomechanics were measured during a single pitching session. Means and standard deviations were calculated for all metrics (significance, P ≤ 0.05) and compared among low-, moderate-, and high-level specialization groups.

Stride length increased significantly (P = 0.03) from low- (mean, 74% height; SD, 13.6; 95% CI, 64.3-83.8) to high-level (mean, 92.9% height; SD, 6.3; 95% CI, 79.7-86.1) specialization. Hip-shoulder separation at foot contact increased significantly (P = 0.01), with low-, moderate-, and high-level specialization demonstrating means of 21.9° (SD, 12.1; 95% CI, 13.3-30.6), 31.1° (SD, 7.0; 95% CI, 27.7-34.4) and 30.0° (SD, 5.3; 95% CI, 27.3-32.8), respectively. Maximum torso rotation velocity and maximum shoulder internal rotation (IR) velocity increased significantly (P = 0.03) from low- to high-level specialization rising from 930.5 deg/s (SD, 68.4) to 1020.0 deg/s (SD, 75.7), and from 4284.2 deg/s (SD, 311.6) to 4827 deg/s (SD, 512.2), respectively. Peak shoulder distraction force also increased significantly from low- to high-level specialization (P = 0.03), rising from 0.81 N (% bodyweight) (SD, 0.13; 95% CI, 0.72-0.91) to 0.96 N (% bodyweight) (SD, 0.12; 95% CI, 0.89-1.02). There were no significant differences among age, height, weight, or pitch speed across pitching specialization level.

Differences in pitching biomechanics were observed among low-, moderate-, and high-level specialized high school baseball pitchers.

Recognizing the impact of sport specialization and negative influences on pitching biomechanics will contribute positively to performance training and injury prevention strategies.