Baseball - Throwing Mechanics

Biomechanical Comparison of Baseball Pitching Among Various Levels of Development

Fleisig GS, Barrentine SW, Zheng N, Excamilla RF, Andrews JR. Kinematic and kinetic comparison of baseball pitching among various levels of development. Journal of Biomechanics 32(12):1371-1375, 1999.

Methods

Researchers from ASMI teamed up with Dr. Rafael F. Excamilla of Duke Sports Medicine to investigate the pitching motion at different levels of competition. 231 pitchers were subjects in the study: youth pitchers (n=23), high school pitchers (n=33), college pitchers (n=115), and professional pitchers (n=60). Their pitching motions were captured using four high-speed (200 Hz) infrared cameras and digitized. Angles, velocities, forces, and torques were then compared using the digitized data.

Results

No significant differences were found in the timing of various parts of the pitching motion among the different levels of development. Only one difference was found in the positions analyzed in the pitching motion – youth pitchers displayed less elbow flexion. This data supports the current belief that young pitchers should be taught proper pitching mechanics, which can be used throughout their pitching career.

Significant differences were found in angular velocity, joint force, and joint torque parameters. Joint forces and torques increased with higher levels of competition. These increases were attributed to increased strength at higher levels of development. Moreover, the authors point out that although field dimensions and bat weight are scaled down for younger players, the balls used in youth leagues are of the same size and mass used in professional leagues. Lighter balls may allow youth pitchers, despite having less strength, to attain similar arm velocities to those generated by adults. Additionally, smaller balls might allow youth pitchers to learn proper grips earlier.

The greater forces and torques placed on pitchers at higher levels may make these athletes more susceptible to injury. This increase in risk is only theoretical however. Due to the complex nature of the forces involved and the variations in muscle mass and tissue strength, it is hard to determine the exact relationship between these factors. The data from this study does however suggest that a pitcher should learn proper mechanics early, and gain strength and fitness as the pitcher matures.