37 collegiate-level overhead athletes who competed in either volleyball, swimming, or tennis, and demonstrated a 15-degree or more deficit in shoulder internal rotation were randomized to either a daily posterior shoulder stretching exercise program or a control group who continued normal activities. The purpose of this study was to determine if the posterior shoulder stretching program demonstrated effectiveness in increasing shoulder internal rotation and horizontal adduction. Patients were assessed at baseline, 4 weeks, and 8 weeks. The posterior shoulder stretching group demonstrated significantly greater increases from baseline in shoulder internal rotation and horizontal adduction compared to the control group after 8 weeks.