Predictors of Throwing Velocity in Youth and Adolescent Pitchers
Sgroi, T., et. al. J Shoulder Elbow Surg. 24(9): 1339-1345, 2015
Purpose: To determine the demographic and biomechanical factors that predict throwing velocity in youth and adolescent pitchers.
Subjects: 420 pitchers between the ages of 12.1 and 17.3 years with a mean age of 14.7 +/- 2.6 years. Mean height was 67.5 +/- 5.3 inches. Mean weight was 145.4 +/- 39.2 pounds. Mean velocity was 64 +/- 10 mph.
Procedures: Demographic data collected included age, height and weight. Biomechanical data were obtained from video motion analysis at 210 Hz while pitching from a regulation practice mound and distance from home plate appropriate for the subject’s level of play. Throwing velocity was measured with a JUGS Sports radar gunwith an accuracy of +/- 0.5 mph. Biomechanical factors measured included: 1) did the pitcher lead with his hips; 2) did he have his hand on top of the ball during the stride phase; 3) did he have his arm in the throwing position at front foot contact; 4) were his shoulders closed at the hand-set position; 5) did he have a closed foot orientation at front foot contact; 6) did he separate the rotation of his hips and shoulders, i.e., during the cocking phase, was his pelvis rotated to face home plate while his shoulders continued to face third base (RHP); and 7) was he in a fielding position at follow-through.
Analysis: Data were analyzed using an Excel X and SPSS 21 software for Student t test, Mann-Whitney test and Pearson correlation coefficients.