The overhead throwing motion is a complex interaction between many different parts of the body. Considering the complexity of motion, early sport participation (most leagues start at 5 years old), and growing sport popularity (an estimated 9 million participants in the U.S.) shoulder and elbow injuries are common.

Starting from the ground, there are many links in the chain of motion which produces throwing force. The motion begins with a strong push off the ground, using force generated by the hips and thighs, carrying upward through the midsection to the shoulder girdle and out through the arm to the hand. Therefore there are many possible points of breakdown, each one affecting the next. Therefore the root of shoulder or elbow pain is not always obvious.

There are many common biomechanical alterations seen in the overhead throwing population such as inadequate core stability, decreased upper or lower extremity flexibility, or muscle imbalance. However, one alteration is quite prevalent and well researched. Many studies have confirmed a relationship between posterior capsular tightness and shoulder and elbow pain. G.I.R.D. (stands for glenohumeral internal rotation deficit) is a difference in internal rotation range of motion between an individual’s throwing and non-throwing shoulders. Comparison of athletes with a history of injury versus healthy players revealed that those with a G.I.R.D. of greater than 20% had a higher risk of injury. The good news is G.I.R.D. is correctable. Data showed that a disproportionate G.I.R.D. can be eliminated with appropriate stretching activities with most athletes returning to pain free throwing. Many participants also reported a feeling of increased throwing effectiveness after the deficit was reduced.

A comprehensive biomechanical evaluation specific to the overhead athlete, culminating in prescription of a customized exercise program will minimize risk of injury and prevalence of activity limiting pain while ultimately enhancing performance. For more information please contact Adam Kerley at TOC Physical Therapy, 865-560-8550 or Champion Sports Training, 865-454-2876.

By Adam Kerley PT, ATC, CSCS