As you might imagine, shoulder injuries are common in football. A 2013 study found that there were a total of 2,486 shoulder injuries over the course of 12 NFL seasons, with 727 (29.2%) of these injuries involving the acromioclavicular joint (1), more informally known as the AC joint. Quarterbacks dealt with these injuries most frequently, followed by special teams players and wide receivers.
Why Football Players are Susceptible to AC Joint Injuries
The AC joint is made up of the acromion, or the bony process on the scapula, and the clavicle, or collarbone. It is the only connection that your shoulder has to your body, other than the soft tissue connections.
Most football-related AC joint separations occur during a game, when a player gets hit and is brought to the ground with the tackling force of the ground beneath you and the other player on top of you. If the force of the tackle is substantial, the soft tissue connections can tear, resulting in separation. In a contact sport like football, injuries such as these are difficult to avoid. However, NFL rules regarding when and where contact can be made with other players, and especially with quarterbacks, may serve to reduce the incidence of contact injuries such as AC joint separations.
When a player suffers a shoulder injury during a game, actual shoulder dislocation and the integrity of all bony structures are the first injuries that the medical team will want to rule out. An x-ray will be ordered to make sure that there are no fractures. After those injuries are ruled out, a general physical exam will be performed. Point tenderness to the AC joint and the mechanism of injury may help to confirm the diagnosis of AC joint separation.
The Impact on Time on the Field
What’s unique about this injury is that most players are able to play through it if it’s only a low grade sprain. The exception involves the quarterback- the AC joint is a major component of the throwing motion, so for them it’s much more difficult to continue to play. Wide receivers, who need to be able to reach overhead, are also more likely to have their time on the field impacted by this injury.
Treatment and Rehabilitation
The first treatment to be applied is an extensive round of ice and compression to the shoulder. Physical therapy may begin as soon as the next day in order to avoid as much strength loss as possible, and consists of controlling the inflammatory response to the injury, as well as maintaining the rotator cuff and periscapular strength to help stabilize the shoulder. The program is likely to include open and close chain rotator cuff activation and strengthening exercises. The player will continue to do cardio and lower body work while the shoulder heals.
Depending on the severity of the injury, recovery may take anywhere from 1-6 weeks. If the AC joint shows gross instability and needs to be stabilized, surgical intervention may be necessary but this injury often responds well to conservative treatment. When the medical staff feels that the joint is stable and the shoulder is strong enough to absorb a hit and return to the rigors of football, the player returns to the field.
1) Lynch. Et al. Acromioclavicular joint injuries in the National Football League: epidemiology and management. Am J Sports Med. 2013: https://www.ncbi.nlm.nih.gov/pubmed/24057030.
Patrick Vignona is a Board Certified Clinical Specialist in Sports Physical Therapy and Certified McKenzie Practitioner, with a Masters in Physical Therapy. He is an Advanced Clinician at the James M. Benson Sports Rehabilitation Center at Hospital for Special Surgery. Patrick has 10+ years of experience in Sports Medicine and Rehabilitation. His primary interests are the Overhead Athlete, Hip Arthroscopy, Ligamentous Knee Injuries, and Return to Play for upper and lower extremities. He has played Division 1 Soccer and is an avid runner/triathlete, and is co-author on several baseball mechanics research articles.