Your acromioclavicular joint (or AC Joint) is located at the top of your shoulder between your clavicle (collarbone) and your scapula (shoulder blade) and is essential in allowing overhead and across your body shoulder movements.
What are the types of AC joint injury?
AC joint disorders can be classified into acute injuries, repetitive strain injuries and degenerative conditions. The diagnosis of an acute AC joint injury (sometimes referred to as a sprain or “separated” shoulder) is often straightforward due to the presence of tenderness, swelling, and deformity.
AC joint disorders from overuse, inflammation, or chronic degeneration can be more difficult to diagnose, particularly if other shoulder problems exist.
Overuse injuries — The AC joint is subject to inflammation from repetitive motion and stress, particularly activities involving an outstretched arm moving across the body.
Acute injuries – Acute AC joint injuries are most common in people younger than 35, with males sustaining more traumatic AC joint injuries than females.
Because younger athletes are more likely to participate in high-risk and collision activities, such as rugby league, biking, and snow sports traumatic AC joint injuries occur most often in this population.
AC joint injuries can be caused by:
- Falling directly on the outside of the shoulder
- Colliding with another player in a contact sport
- Falling onto an outstretched hand
- Lifting heavy weights overhead
A traumatic impact can push the top of the shoulder blade underneath the end of the collarbone, damaging the capsule surrounding the AC joint and the ligaments which support the joint.
What are the symptoms of an AC joint injury?
AC joint ligament damage can vary from a mild strain of one or more of the surrounding ligaments to complete ligament tears and deformity. The first sensation felt when the AC joint is injured is pain on the top of the shoulder. After this, you may also have a mix of:
- A visible bump above the shoulder
- Swelling and tenderness over the AC joint
- Loss of shoulder strength
- Loss of shoulder motion
- A popping sound or catching sensation with movement of the shoulder
- Discomfort with daily activities that stress the AC joint, like lifting objects overhead, reaching across your body, or carrying heavy objects at your side
AC joint injuries can be identified and effectively treated by a physiotherapist.
It is advised that all AC joint injuries are fully assessed by a physio in order to prevent ongoing shoulder pain and an increased risk of re-injury when you return to normal activities.
Your Fixio physio will examine your shoulder and assess your sensation, motion, strength, flexibility, tenderness, and swelling. They will then perform several tests and may also ask you to briefly demonstrate the activities or positions that cause your pain.
Your neck and upper back will also be examined to determine whether they, too, might be contributing to your shoulder condition through referred pain processes.
How can physiotherapy help treat an AC joint injury?
Physiotherapy for an AC joint injury is very important. Once an injury to the AC joint is diagnosed, your physio will work with you to develop a bespoke plan tailored to your specific shoulder condition and your goals. There are many physio treatments that have been shown to be effective in rehabilitating AC joint injuries, including:
- Range of Motion – An injury to the AC joint often causes swelling and stiffness, causing loss of normal motion.
- Strength Training – After an AC joint injury, your physiotherapist will design a bespoke exercise program to strengthen the muscles around the shoulder, so that each muscle is able to properly do its job.
- Manual Therapy – Physiotherapists are trained in hands-on therapy and will gently move and mobilise your shoulder joint and surrounding muscles as needed to improve their motion, flexibility, and strength.
If you have any questions regarding your AC joint injury (or any other condition), please contact your Fixio physio to discuss and organise an appointment to get your recovery on track.
