Association Between Pitching Volume And Shoulder And Elbow Injury In High School Baseball Pitchers

Abstract

There is widespread concern that the incidence of pitching injuries is rapidly rising in youth baseball. Understanding the risk factors surrounding these injuries is essential to their prevention. Excessive pitching volume (number of pitches thrown per day) is considered to be a risk factor for arm injury, but limited evidence exists addressing this supposed association. PURPOSE: To examine the associations between 2 markers of excessive pitching volume (arm tiredness and arm pain) and elbow and shoulder injuries in high school baseball pitchers. METHODS: 295 High School (age=15.94 ± 1.27 years) baseball pitchers were surveyed during the 2007 baseball season. The survey asked questions about injury causing significant time loss from pitching and possible risk factors. We examined two risk factors: 1) pitching with arm tiredness and, 2) pitching with arm, shoulder, and elbow pain. Our outcome was any injury causing significiant time loss from baseball pitching. RESULTS: Twenty percent of pitchers reported an elbow injury and 13.6% reported a shoulder injury. Forty percent reported pitching with some type of elbow, shoulder or arm pain while seventy-three percent reported pitching when their arm was tired. Chi-Square analyses revealed significant associations between pitching with elbow pain and elbow injury; pitching with shoulder pain and shoulder injury; and pitching when the arm or shoulder was tired and shoulder pain. (p < 0.01) A trend was also observed in the association between pitching when the arm was tired and pitching with elbow pain (p=0.07) Also, 15% of these pitchers reported pitching in more than one league in at least one week of their season. CONCLUSION: Pitching with pain and tiredness are associated cross-sectionally with arm injury. Our study supports the concept of pitch-count regulations; however, implementation of these regulations is problematic as significant numbers of pitchers play in more than one league simultaneously. The next phase of this research (currently in progress) will address similar hypotheses using longitudinal analyses. Nevertheless, our preliminary findings are alarming. Chronic overuse and stress may predispose young athletes, whose musculosketelal physique is still developing, to future injuries and subsequent problems in later life. Funding: Yawkey Foundation