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HealthInfo Waitaha Canterbury

AC joint injuries

Ngā whara ki te hononga pokohiwi-manumanu

Your AC, or acromioclavicular (ak-ro-me-o-kla-vik-u-lar), joint is the joint at the very top of your shoulder. Injuries to this joint usually happen because you've fallen directly onto your shoulder.

An injured AC joint can range from mild to severe. You may feel a lot of pain at the top of your shoulder, which is made worse when you try to lift anything heavy, lift your arm above your head or move it across your body. It may be hard to move your arm at all. You may also see:

If your injury is not too bad, you'll need to follow a programme of rest and exercise to help your joint heal. If your injury is more severe, you may need surgery.

Diagnosing an AC joint injury

Your doctor or physiotherapist can diagnose a dislocated AC joint by listening to what happened and examining your shoulder. Depending on your injury and the symptoms, you may need an X-ray but not every shoulder injury needs an X-ray.

Self-care for an AC joint injury

There are some things you can do to help your recovery, whether or not you're having surgery.

Treating AC joint injuries

AC joint injuries are usually treated by resting your arm and shoulder in a sling until the pain starts to get better.

You should keep your arm in a sling at a right angle – this puts the least stress on the injured part of your shoulder. At first, wear the sling under your clothes, as this will act like a splint for your arm and keep your shoulder still. Do not drive while your arm is in a sling.

If you have a simple injury, physiotherapy may help get you back to your normal activities and sport.

If your injury is more severe or if a simple injury doesn't get better with resting and physiotherapy, you may need surgery to help the injury heal.

If you need surgery, your doctor or physiotherapist will refer you to an orthopaedic (bone) surgeon. Precisely what operation you have, the risks and benefits and how long it will take you to get better will depend on the details of your injury. Your surgeon will talk to you about this.

Surgery usually involves spending one night in hospital. Afterwards, your arm will be in a sling for six weeks, which means you will not be able to drive for six weeks. You'll also have a course of physiotherapy to strengthen your shoulder and get it moving again.

You may need some time off work. How long will depend on the type of injury and the type of work you do. Your doctor or physiotherapist will guide you on whether you can work with your injury.

While you're recovering, it's best not to lift or carry anything on the injured side. For the six weeks your arm is in a sling you shouldn't lift anything at all – not even a cup of tea or coffee. After that you'll gradually be able to increase what you can lift and carry. But you shouldn't lift anything heavy until you have normal movement back in your arm. Your surgeon will let you know when it's safe to start lifting.

Getting help for an AC joint injury

If you have any concerns about how you're healing or have a lot of pain, see your general practice team.

If your arm feels stiff after the pain has gone and you're no longer wearing a sling, see a physiotherapist who can help you with exercises and help strengthen your arm.

ACC may be able to provide help while you aren't fit for work, such as home help or taxis to appointment as well as work compensation payments.

Shoulder shrugs and shoulder blade squeeze exercises

shoulder shrugs

Shoulder shrugs (left)

Sit or stand in a relaxed position. Shrug your shoulders up to your ears and hold for three seconds. Lower them down as far as you can go. Repeat this 10 times.

Shoulder blade squeeze (right)

Sitting tall, move your shoulder blades forwards, then backwards as far as you can take them. Squeeze your shoulder blades together at the back and hold for three seconds. Repeat this 10 times.

Shoulder adduction and abduction, flexion and extension exercises

SA flexion extension

Adduction and abduction (left)

Lean on a table with your unaffected arm. Swing your affected arm outward and inward, like a pendulum. Let gravity do most of the work. Do this for two to three minutes.

Flexion and extension (right)

Lean on a table with your unaffected arm. Swing your affected arm backwards and forwards, like a pendulum. Let gravity do most of the work. Do this for two to three minutes.

Written by HealthInfo clinical advisers. Last reviewed July 2022. Last updated August 2023.


See also:

ACC help after an injury

Page reference: 34287

Review key: HISHI-13267