Injuries are at epidemic proportions among baseball pitchers, with nearly every adult pitcher sustaining a serious elbow or shoulder injury at some point in his career.  Pitching injuries are difficult to understand and prevent, as most are the result of trauma accumulated during years of pitching.  For decades, experts have argued that the number of pitches thrown, types of pitches thrown, and quality of pitching mechanics are related to arm pain and subsequent injury.  These relationships, however, have never been investigated scientifically.

To elucidate how pain develops in pitchers, the USA Baseball Medical & Safety Advisory Committee sponsored an American Sports Medicine Institute study of factors related to shoulder and elbow pain at the youth baseball level.  In this study, participants included 476 youth baseball pitchers who volunteered to be followed for one season. These 9-14 year old pitchers were from youth baseball parks throughout Alabama, including Little League, Dixie Youth, and Birmingham Metro League parks.  Coaches and players were interviewed before the season, after each game, and after the season, thereby providing the very first account of pain and playing habits during the course of a season.  The major findings of the study were:

• The incidence of elbow or shoulder pain increased with the number of pitches thrown in a game.

• The incidence of elbow or shoulder pain increased with the number of pitches thrown in a season.

• Pitchers who threw curveballs or sliders had greater incidence of pain than those who didn’t.

• No relationship between poor mechanics and increased risk of pain could be established.

Based upon the results from this study, it is recommended pitchers between 9 and 14 years old do not throw the curveball or slider.  These pitchers should utilize the fastball and change-up exclusively.  The data also suggest that baseball organizations consider limiting pitch counts for 9 to 14 year old pitchers.  More specifically, it is proposed that pitch counts be limited to 75 pitches per game and 600 pitches per season.  These pitch count recommendations refer to full effort, competitive game pitches and do not include warm-up pitches, practice pitches, throwing from other positions, and throwing drills, which are all vital for a pitcher’s development.  This advice is consistent with recommendations previously published by USA Baseball (USA Baseball News, April 1996).  Since youth pitchers average approximately five pitches per batter, alternative regulations could be 15 batters faced per game and 120 batters faced per season.  Pitchers should not be allowed to circumvent pitch limits by participating in more than one league at a time (USA Baseball News, March 1997). 

While this study presents new, valuable data, it represents only a foundation for future research.  Prospective studies are needed to correlate pitching parameters (pitch counts, pitch types, and pitching mechanics) with injury (surgery, time missed) developed during a career.  Specifically, researchers must follow the careers of pitchers from their youth through adult years.  The current study implies that youth pitchers deserve the same concern that adult pitchers receive, namely that pitch counts and pitch types should be monitored to better understand and prevent pitching problems.

USA Baseball Medical & Safety Advisory Committee - Position Statement on Youth Baseball Injuries based on publications from ASMI 

Copyright © 2000, American Sports Medicine Institute
August 30, 2006