Baseball, the most American of sports, has generated an epidemic of type 2 SLAP (superior labrum, anterior to posterior) lesions—the most American of shoulder injuries. While the rest of the world concerns itself with soccer, track, and rugby, many young US men spend their spring and summer hours attempting to propel a baseball at speeds of up to 100 miles per hour.

The understanding of throwing injuries has come a long way over the past several years, but that insight has required a sophisticated integration of anatomy, kinesiology, and biomechanics. By studying shoulder injuries in throwers, physicians have been able to develop broad principles of treatment and prevention that apply to all overhead-throwing athletes and nonathletes. Interest in overhead athletic injuries is at an all-time high and has helped turn the “dead arm” into a very lively subject.