Nearly 52% of the injured group regularly pitched despite arm fatigue, compared with 11% of the control group. Approximately 67% of the injured group pitched despite arm pain, compared with 42% of the controls.Through multivariable analysis, we found that a pitcher who regularly pitches despite arm fatigue is at 36 times increased risk of injury. In our clinical experience, history is quite valuable for diagnosing an injury. We suggest that parents and coaches also recognize the value of direct communication with young athletes and listen to players who indicate fatigue or pain