If your child is a pitcher, he/she has about a fifty-fifty chance of experiencing pain in his/her elbow or shoulder during his/her baseball career.
A 2002 study in the American Journal of Sports Medicine found:
roughly half of the 476 youth pitchers studied reported elbow or shoulder pain at least once during the season.
The risk of shoulder pain was 2 and a half times greater for pitchers who threw more than 75 pitches per game
For pitchers who self-reported pitching while tired, the risk of elbow pain was 6 times greater and the risk of shoulder pain increased four-fold.
A 2005 study in the same journal found that overuse was the overriding factor in the development of arm pain among pitchers in youth baseball. That study found that:
Pitchers who averaged more than 80 pitches per appearance were nearly 4 times more likely to require arm surgery;
Pitchers who pitched competitively more than 8 months per year were 5 times more likely to require surgery; and
Other studies have found that:
26% of youth players and 58% of high school pitchers experience elbow pain
The epidemic of arm injuries suffered by youth baseball pitchers is reflected in the dramatic increase in the number of shoulder and so-called Tommy John elbow (ulnar) ligament-transplant operations performed by Dr. James Andrews at ASMI:
Research by the ASMI and others points to three principal risk factors for injury to youth baseball pitchers: overuse (number of pitches during a game, season, and a year), poor pitching mechanics, and poor physical fitness/physical conditioning.
Most baseball arm injuries are not the result of a single traumatic event. Instead, injuries are believe to be due to the cumulative effect of microscopic trauma from the repetitive act of pitching. Overuse occurs throughout the course of a single game, season, or year in the developing baseball player.
Poor pitching mechanics has been suggested as a possible risk factor for injury, but such a link has yet to be shown in bio-mechanical or clinical studies.
Of the three, experts seem to agree that the number of pitches thrown coupled with the lack of appropriate rest periods are the greatest contributor to the increasing incidence of pitcher arm injuries.