Robert Wood Johnson University Hospital
New Brunswick • Somerset

Preventing Shoulder, Elbow Injuries in Youth Baseball

March 10, 2010
David A. Abrutyn, M.D.

Baseball is our national pastime. As Hall of Fame pitcher and Yankee great, Whitey Ford, once said, “Pitching is the most glamorous position in baseball.” In an effort to maintain the glamour and competitive advantage required to maximize the development of our young players, the game has evolved into a year-round sport. 
The young athlete typically plays not only Little League but on multiple teams, year-round with limited rest. This places exceptional demands on the athletes’ shoulder and elbow, particularly, pitchers and catchers. The overhead throwing motion creates exceptional stress on the shoulder and elbow. This can alter the anatomic development of the upper extremity and create adaptive changes that can lead to altered throwing mechanics and eventual pain in the throwers’ shoulder or elbow. 
The simplest way to decrease the effects of throwing is to limit the number of pitches thrown. In addition, the young athlete needs to preemptively improve their core strength, scapulothoracic conditioning, maintain range of motion and hone their pitching mechanics. Injury prevention is the responsibility of our coaches, parents, trainers, and sports medicine physicians. However, in order to prevent injuries it is important to understand throwing mechanics and the adaptive changes that occur.
Throwing, particularly pitching, is the result of a coordinated movement of the shoulder, elbow, scapula, torso, pelvis and lower legs. In order to generate the most speed and accuracy the throwing motion must covert energy from the lower extremity into the shoulder and elbow. The throwing motion is typically divided into 6 phases: windup, early cocking, late cocking, acceleration, deceleration, and follow-through. In order to increase velocity, pitchers typically maximally externally rotate during the late cocking phase and begin acceleration. This leads to significant torsional stress on the shoulder and valgus stress at the elbow. Adaptively, in the skeletally immature thrower, changes can occur at the growth plate and in glenohumeral range of motion. 
Improper mechanics combined with these adaptive changes, ultimately, can result in a painful shoulder or elbow with repetitive throwing. Little league baseball has recently updated their rest requirements for 2010.
Pitchers league age 14 and under:
*If a player pitches 66 or more pitches in a day, four (4) calendar days of rest must be observed.
*If a player pitches 51-65 pitches in a day, three (3) calendar days of rest must be observed.
*If a player pitches 36-50 pitches in a day, two (2) calendar days of rest must be observed.
*If a player pitches 21-35 pitches in a day, one (1) calendar day of rest must be observed.
* If a player pitches 1-20 pitches in a day, no (0) calendar day of rest is required.
Pitchers league age 15-18:
*If a player pitches 76 or more pitches in a day, four (4) calendar days of rest must be observed.
*If a player pitches 61-75 pitches in a day, three (3) calendar days of rest must be observed.
*If a player pitches 46-60 pitches in a day, two (2) calendar days of rest must be observed.
*If a player pitches 31-45 pitches in a day, one (1) calendar day of rest must be observed.
* If a player pitches 1-30 pitches in a day, no (0) calendar day of rest is required.

Recommendations for injury include avoiding breaking pitches (ie, curveball, sliders) until skeletal maturity and avoiding year-round throwing. Pitchers and catchers should have a minimum of 2 to 3 months complete rest per year. Proper biomechanics are often overlooked until the high school years. However, young pitchers should consider functional muscular surveys (FMS) by a certified trainer. This can identify specific weakness involved in the throwing motion, particularly core stability and lower leg strength. Furthermore, proper stretching of the glenohumeral joint is essential for maintaining motion. 
Early recognition is the best way to prevent permanent damage to the throwing athlete. Immediate cessation from throwing can prevent further injury and inflammation to the shoulder and elbow. However, proper evaluation by a sports medicine physician can help identify the cause of the problem and allow the athlete to eventually return to throwing—pain free.

Dr. Abrutyn is a board-certified orthopedic surgeon at Somerset Medical Center and is the team physician for Immaculata High School and Sky Blue soccer.