Updated April 2013

With the rise in elbow and shoulder injuries in youth baseball pitchers, the adult community needs to take steps to prevent these injuries. Research points to overuse as the principle risk factor. Poor pitching mechanics also contribute to injury risk. Another suggested risk factor is poor physical fitness.

Throwing curveballs has been suggested as a risk factor, but the existing research does not support this concern. However, a youth pitcher may not have enough physical development, neuromuscular control, and proper coaching instruction to throw a curveball with good mechanics. Throwing curveballs too early may be counter-productive, leading to arm fatigue as well as limiting the youth's ability to master fastball mechanics.

Thus, the recommendations for preventing injuries in youth baseball pitchers are:

1. Watch and respond to signs of fatigue (such as decreased ball velocity, decreased accuracy, upright trunk during pitching, dropped elbow during pitching, or increased time between pitches). If a youth pitcher complains of fatigue or looks fatigued, let him rest from pitching and other throwing.
2. No overhead throwing of any kind for at least 2-3 months per year (4 months is preferred). No competitive baseball pitching for at least 4 months per year.
3. Do not pitch more than 100 innings in games in any calendar year.
4. Follow limits for pitch counts and days rest.
5. Avoid pitching on multiple teams with overlapping seasons.
6. Learn good throwing mechanics as soon as possible. The first steps should be to learn, in order: 1) basic throwing, 2) fastball pitching, 3) change-up pitching.
7. Avoid using radar guns.
8. A pitcher should not also be a catcher for his team. The pitcher-catcher combination results in many throws and may increase the risk of injury.
9. If a pitcher complains of pain in his elbow or shoulder, discontinue pitching until evaluated by a sports medicine physician. Inspire youth pitchers to have fun playing baseball and other sports. Participation and enjoyment of various physical activities will increase the youth's athleticism and interest in sports.

Example limits for number of pitches thrown in games

Example high school limits (not verified by ASMI) shown here. 

For further discussion on this topic, visit the ASMI Forum.

References:

• Dun S, Loftice J, Fleisig GS, Kingsley D, Andrews JR. A biomechanical comparison of youth baseball pitches: is the curveball potentially harmful?Am J Sports Med. 2008; 36(4):686-692.
• Fleisig GS, Andrews JR, Cutter GR, Weber A, Loftice J, McMichael C, Hassell N, Lyman S. Risk of serious injury for young baseball pitchers: a 10-year prospective study. Am J Sports Med. 2011; 39(2):253-257.
• Fleisig GS, Andrews JR, Dillman CJ, Escamilla RF. Kinetics of baseball pitching with implications about injury mechanisms. Am J Sports Med. 1995; 23:233-239.
• Fleisig GS, Weber A, Hassell N, Andrews JR. Prevention of elbow injuries in youth baseball pitchers. Curr Sports Med Rep 2009; 8(5):250-254.
• Lyman S, Fleisig GS, Andrews JR, Osinski ED. Effect of pitch type, pitch count, and pitching mechanics on risk of elbow and shoulder pain in youth baseball pitchers. Am J Sports Med. 2002; 30(4):463-468.
• Matsuo T, Fleisig GS, Zheng N, Andrews JR. Influence of shoulder abduction and lateral trunk tilt on peak elbow varus torque for college baseball pitchers during simulated pitching. J Appl Biomech. 2006; 22(2): 93-102.
• Nissen CW, Westwell M, Õunpuu S, Patel M, Solomito M, Tate J. A biomechanical comparison of the fastball and curveball in adolescent baseball pitchers. Am J Sports Med. 2009 37(8):1492-1498.
• Olsen SJ, Fleisig GS, Dun S, Loftice J, Andrews JR. Risk factors for shoulder and elbow injuries in adolescent baseball pitchers. Am J Sports Med.2006; 34(6):905-912.
• Petty DH, Andrews JR, Fleisig GS, et al. Ulnar collateral ligament reconstruction in high school baseball players: clinical results and injury risk factors. Am J Sports Med 2004; 32:1158-1164.