The acromioclavicular (AC) joint is commonly injured in lacrosse from player to player contact or associated with stick contact, directly made to the top of the shoulder. Another cause of injury can be falling on an outstretched hand. There are several classifications of AC joint injury, or separation, based on severity: types 1-6. Types 1-3 can be treated conservatively, whereas anything about type 3 requires surgical intervention. Type 1-3 AC joint sprain / separation involve partial to complete tears of the ligaments surrounding the joint. Type 2 and 3 cause a visually noted step deformity, where the clavicle is raised higher than the acromion.

When an AC joint injury is sustained, it is important to immobilize the athlete’s arm close to their body in a sling and then follow up with an orthopedic for a formal diagnosis. The initial goal of physical therapy is to decrease pain and inflammation and progress shoulder range of motion. Overhead reaching and lifting should be avoided until properly healed and athletes should use the opposite arm when able for daily activities. Once full range of motion is restored, rehab will focus on strengthening and progressing the athlete to return to sport.