Acromioclavicular (AC) Joint Injury

What is the AC joint?

The AC joint makes up part of the shoulder structure. It is the point in the shoulder where the collar bone meets the shoulder blade, and forms a pointy protrusion near the top outer edge of the shoulder.

The joint is given stability by a number of ligaments and joint capsule. Most commonly, the acromioclavicular and coracoclavicular ligaments are usually damaged.

How is the AC joint injured?

Often occurs as a result of a direct blow to the tip of the shoulder. For example it can occur by falling onto the shoulder in a tackle. It can also occur with a fall onto an outstretched hand with the arm completely straight.

What are the Signs and Symptoms of an AC joint injury?

• Pain at the tip of the shoulder
  
• Swelling at the tip of the shoulder
  
• May have a step-deformity depending on the extent of the injury
  
• Pain on moving the shoulder, especially above chest height and across the body.

What should I do if I suspect I may have injured my AC joint?

Get yourself in a sling and follow RICER for 48-72 hours and avoid HARM.

Most AC joint injuries are treated conservatively, so make sure you get in to see one of our Physiotherapists ASAP. They will be able to determine the extent and grade of the injury, as this will determine how long recovery will be and provide the appropriate treatment.

This may include:

• Shoulder mobilisations
  
• Movement and strengthening exercises
  
• Activity modification
  
• Massage
  
• Taping of the AC joint and shoulder
  
• Referral for X-ray or surgical opinion if required.