Effect of Pitch Type, Pitch Count, and Pitching Mechanics on Risk of Elbow and Shoulder Pain in Youth Baseball Pitchers
Lyman S, Fleisig GS, Andres JR, Osinski ED. Effect of pitch type, pitch count, and pitching mechanics on risk of elbow and shoulder pain in youth baseball pitchers. The American Journal of Sports Medicine 30(4):463-468, 2002.
Methods
Researchers from ASMI and the American Baseball Foundation (ABF) followed 476 baseball pitchers ages 9-14 for one season in the spring of 1999. Data was collected from the pitchers using pre-season and postseason questionnaires, injury and performance interviews following each game, pitch count logs, and video analysis of pitching mechanics. The pre-season and postseason questionnaires were used to determine the types of pitches thrown (of particular interest were the fastball, change-up, curveball, and slider). Interviews were performed by phone, and included questions regarding stiffness and pain in the shoulder and elbow. Pitch counts were calculated as pitches per game and pitches per season.
Results
The 476 pitchers used in the study pitched 3789 games during the 1999 spring season. Almost 7% (254 of 3789) of those appearances resulted in elbow pain, and over 9% (353 of 3789) resulted in shoulder pain. Elbow pain was reported by 28% (134 of 476) of the subjects at least once during the season, while shoulder pain was reported by 35% (165 o 476) of the subjects. Half of the subjects in the study reported either elbow or shoulder pain at least once during the season.
The study evaluated the relationship between the types of pitches thrown (fastball, change-up, curveball, and slider) and shoulder or elbow pain. Pitchers in the 9-14 age bracket who threw sliders were 86% more likely to experience elbow pain during the season. Pitchers who threw curveballs were 56% more likely to experience shoulder pain during the season. On the other hand, pitchers who threw change-ups were 12% less likely to experience elbow pain and 29% less likely to experience shoulder pain, although these findings were not statistically significant.
The study also found that as pitch counts increased, the number of cases of shoulder and elbow pain also increased. At the 75-99 pitch count range, the risk of shoulder and elbow pain increased by 52% and 35% respectively.
The authors recommended that pitchers between the ages of 9 and 12 should limit themselves to throw only fastballs and change-ups, and not throw sliders or curveballs. Baseball organizations should also consider limiting the number of pitches throw to 75 pitches per game and 600 pitches per season. Limiting the amount of pitches thrown could also be accomplished by limiting the number of batters faced to 15 batters per game and 120 batters per season. The pitch counts refer to full effort, game pitches only and does not include practice, warm-up, or drill pitches, which are important in developing the mental and physical skills necessary for the development of young pitchers.
Copyright © 2000, American Sports Medicine Institute
October 05, 2004
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