ACJ Injury


What is it?

The acromioclavicular joint (ACJ) is a small joint in your shoulder that connects your collar bone (clavicle) to your shoulder gridle (acromion). Its role is to stabilise the shoulder during movement and when putting weight through your arm. The ACJ has 3 main ligaments: the superior and inferior acromioclavicular ligaments and the coracoacromial ligament (which is composed of 2 expansions).
An injury to the ACJ involves a stretch or sprain to any of these ligaments on the lateral end of the clavicle.

What causes it?

An ACJ injury can be caused by direct or indirect trauma. Direct trauma is caused by landing on the outside point of your shoulder with force. For example, falling off your bike or landing on your shoulder during a rugby tackle. An indirect injury is caused by landing with force on an outstretched arm, an example would be saving yourself from a fall.

What does it feel like?

The pain with an ACJ injury is localised specifically to the joint and you will be able to touch where it hurts. It will feel sore and may swell shortly after the injury. Depending on the severity of the injury, your collar bone may be slightly raised compared to the other side. This is due to stretching or tearing of the ligaments and is called a step deformity.
You may find it uncomfortable to move your arm above shoulder height and it may feel sore to lean on your elbow or lie on your injured side.

How is it diagnosed?

A less severe injury can be diagnosed by your Physiotherapist, but a more severe injury may warrant an assessment by a doctor and an X-ray. The same mechanism can cause several different shoulder injuries, including a break in your collar bone. If a fracture is suspected, then an X-ray is needed in-order to see the extent of the injury.
Your Physiotherapist will assess your symptoms and go through specific movements and tests to diagnose your injury.

How can Back in Action Physiotherapy help?

Your Physiotherapist will be able to diagnose your injury and guide you through an individualised rehabilitation programme depending on your needs. They will observe how your shoulder and shoulder blade are moving. This is important as your injury may have affected how the shoulder girdle moves. They will also assess your strength, and with the findings of the assessment give you strengthening and control exercises to help improve your symptoms. They will look at other joints around the shoulder complex and the neck to check that they are moving well. They will also advise you on what activities to avoid initially and then progress you on to returning to the activity or sport that you love!