Gabe Mirkin, M.D.
A study from The American Sports Medicine Institute shows that young baseball pitchers are most likely to be injured by throwing curveballs and sliders. Four hundred and seventy-six baseball pitchers, aged 9 to 14, were followed for one season by pre- and post-season questionnaires, injury and performance interviews after each game, pitch count logs, and video analysis of pitching mechanics. Half of the boys suffered elbow or shoulder pain during the season.
The pitchers who threw curveballs had a 52 percent increased risk of shoulder pain and those who threw sliders had an 86 percent increased risk of elbow pain. Those who threw the most pitches were the most likely to be injured. This study suggests that young baseball pitchers should not throw curveballs and sliders until they have thrown for several seasons. They should also not throw hard more often than every third day, and they should probably practice pitching 12 months a year.