Thursday, June 4, 2020

Acromioclavicular Joint (ACJ) injuries by William Dao

What is the injury?

The ACJ is the joint between the collarbone (clavicle) and the acromion process which is the bony point on the top shoulder of the shoulder blade (scapula). You can feel this joint yourself – it is the bony protrusion on the top, outer part of the shoulder. Injuries to this joint often occur in younger and more active individuals. Injuries to this joint often involve tears to the ligaments (acromioclavicular and coracoclavicular ligaments). In more severe cases, there can be damage to the joint capsule and cartilage within the joint which will cause a bony protrusion to appear at the top of your shoulder. Damage of the cartilage has the potential to lead to early arthritis of the joint.

Severity of ACJ injuries can be graded in six types (Type I to Type VI). Physiotherapy has been shown to be effective for type I-III whereby there is a sprain or rupture of the ligaments without significant disruption of other structures. However, some deformity of the clavicle can be seen in a Type III injury. Type IV to VI injuries will require surgery.



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How did I get this injury?

Injury to the ACJ is almost always linked to a particular incident, unless it is arthritic or overuse in nature. The mechanism of injury can be direct or indirect. Direct impact onto the shoulder can cause an ACJ injury. Indirect injuries are when the impact or force are through the arm instead of the shoulder itself. For example, falling onto an outstretched arm or elbow and the force shoots through into the ACJ causing an injury to the joint. Type III injuries and above are often caused by high impact incidents like high speed contact sports, skiing/snowboarding, falling from a height and motor vehicle accidents.

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How long will it take to fix?

It all depends on the severity of the injury, compliance with professional advice/exercises and whether or not you need surgery.
For the general population who seek Physiotherapy – Type I injuries can take approximately 4-6 weeks for return to normal activity and type II injuries can take 6-12 weeks for return to normal activity. However, function and activity of the shoulder can be limited for more than 6 months for injuries not requiring surgery.

For those who require surgery, strengthening (as you know it) often commences from the 3 month mark, full loading of the shoulder is often tolerated by the 6 month mark, therefore advanced level of sports rehabilitation can go well beyond the 6 month mark.

For mild injuries that are simply left alone to heal will most likely NOT truly get better. There is always a potential for ongoing pain, swelling, limited range of motion and limited function. Regardless of management, there is also a possible consequence of degenerative changes post ACJ injury.



What do I need to do to Fix it?

Protecting the shoulder by wearing a sling and getting confirmation of the severity of the injury is the most important in the first place.
Physiotherapy has been shown to be effective for Type I and II ACJ injuries. Management for Type III type ACJ injuries can be a little more grey. Physiotherapy has been shown to help with Type III injuries but Physiotherapy alone is unable to fix the bony deformity from the displaced clavicle. This will require surgery. However, in some cases Type III injuries may still fail with Physiotherapy and rehabilitation alone and might require surgery at a later date. Therefore, the decision for management in Type III injuries is dependent on the requirements and expectations in each individual case.


Physiotherapy will generally encompass the following:

  • Pain management through education, manual (hands-on) therapy, taping and/or acupuncture initially as it is crucial to give the injured ACJ a chance to recover.
  • Manual therapy and exercises to improve the range of movement of the shoulder, neck and upper back.
  • A strength and control program to aid with regaining specific muscular control around the shoulder and shoulder blade in particular
  • Sports or task specific strengthening with incorporation of plyometric (explosive) type exercises to regain advanced function of the shoulder. This type of training usually extends beyond just the shoulder and ACJ itself because high level tasks requires more than just one body part to function well.

If you have any further questions on Acromioclavicular joint or any of our other blogs then please email us at or come and see us at Fix Physio Sydney in Sydney CBD Do not let this problem linger. Shoulder pain can be very stubborn.