Proximal Humeral Epiphysiolysis (Little Leaguer’s Shoulder) Little Leaguers’ Shoulder is a term that is used to describe pains and discomforts that pitchers and other overhead athletes have in their shoulder when the growth plate in the upper arm (humerus) is injured. Growth plates are referred to as physes and therefore the problem is formally referred to as proximal humeral epiphsiolysis. The differential diagnosis includes rotator cuff tendinitis, mild multidirectional instability (MDI), and sometimes labral tears. Epiphysiolysis occurs when the strain on the proximal humeral growth plate exceeds its fatigue and tensile strength causing it to separate. It is analogous to a green stick type fracture in that no significant displacement occurs in the bone itself. Epiphysiolysis is seen on the outside (lateral) aspect of the proximal humeral physis as seen on X-ray. MRI can be used in some cases to show bony edema or swelling at the location of the injury. Causes Repetitive throwing without adequate rest in the adolescent overhead throwing athlete Overuse Signs & Symptoms Aching pain in the shoulder primarily after throwing Sharp pain on the otter aspect of the shoulder with throwing Tenderness to palpation to the outer aspect of the proximal humerus at the growth plate Treatment Initially little leaguer’s elbow is treated with active rest. Avoiding any activities that cause pain, both during and after, for 6 weeks (average). During this rest, the athlete will remain active but pain-free while being sure to avoid any repetitive stress to the shoulder. Following the course of rest, physical therapy (to gain flexibility and to strengthen the shoulder blade muscles) and a gradual return to throwing through an interval throwing program may begin. If there is no pain or setbacks during the gradual return to sport, then a full return is warranted.