That painful bump on the top of your shoulder after a fall or tackle? There is a good chance you have injured your AC joint. AC joint injuries are common, especially in contact sport and after landing on the shoulder, and while they can look alarming, most recover well without surgery.
In this guide we explain what the AC joint is, how to know if you have injured it, sometimes called a shoulder separation, what the grades mean, and how physiotherapy helps with the shoulder pain and recovery, including whether that bump will go away.
What Is the AC Joint?
The AC joint, or acromioclavicular joint, is the small joint at the top of your shoulder where your collarbone meets the tip of your shoulder blade. It helps you lift and move your arm overhead. Because it sits right on top of the shoulder, it is vulnerable to direct knocks and falls, which is why it is a common site of injury.
How These Injuries Happen
Most of these injuries happen from a direct force to the shoulder, typically a fall onto the point of the shoulder or an outstretched arm, or a heavy tackle. This is why they are so common in contact and collision sports like rugby and football, as well as in cycling and skiing crashes. The force sprains or tears the ligaments holding the joint together.
Signs You’ve Injured Your AC Joint
How do you know if it is the culprit? The classic signs are shoulder pain right at the top of the shoulder, tenderness over the joint, and often a visible bump or step where the collarbone lifts up. The shoulder pain usually worsens when you reach across your body, lift overhead, or lie on that side. If you have these after a fall or knock, an AC joint injury is likely.
AC Joint Injury Grades Explained
These injuries are graded by severity. Lower grades are sprains, where the ligaments are stretched or partly torn but the joint stays largely in place, and these usually heal well with conservative care. Higher grades involve more complete tearing and a more obvious step deformity. The grade helps guide treatment, though how your shoulder functions matters just as much as the grade itself.
Is It a Shoulder Separation?
You may hear this injury called a shoulder separation, and that is the same thing. Importantly, a shoulder separation is not the same as a dislocated shoulder, which involves the main ball-and-socket joint. A shoulder separation specifically involves the joint at the top of the shoulder. The names get mixed up, but a physiotherapist can quickly clarify what you are dealing with.
How These Injuries Are Treated
The good news is that most of these injuries, especially lower grades, are treated successfully without surgery. Early on, the focus is settling the shoulder pain and protecting the joint, sometimes with a sling for comfort. From there, physiotherapy restores movement and rebuilds the strength of the shoulder so it can handle load again. Higher-grade injuries are sometimes considered for surgery, but that decision is made with a surgeon, and many high grades still do well with rehab.
Will the Bump Go Away?
This is the question everyone asks. With higher-grade injuries, the bump, that raised step where the collarbone sits high, may not fully disappear, even once you have recovered. The reassuring part is that the bump is usually cosmetic: most people regain full, pain-free function and return to everything they love, even if a small bump remains. Function matters far more than appearance.
Recovery and Return to Sport
Recovery depends on the grade. Milder injuries often settle over a few weeks, while higher grades take longer. Returning to sport is guided by regaining full, pain-free movement, strength and confidence, not just time. Rushing back before the shoulder is ready risks re-injury, so a gradual, criteria-based return with your physiotherapist is the smart approach.
Common Questions About AC Joint Injuries
What is an AC joint injury?
It is an injury to the joint at the top of the shoulder where the collarbone meets the shoulder blade, usually from a fall or knock. It is also called a shoulder separation.
Do I need surgery?
Usually not. Most of these injuries recover well with physiotherapy. Surgery is considered for some higher-grade injuries, and that decision is made with a surgeon.
How long does it take to heal?
It depends on the grade. Milder ones often settle in a few weeks, while higher grades take longer. Your physiotherapist can give you a clearer timeline after assessing it.
Will the bump go away?
With higher grades, the bump may not fully disappear, but it is usually just cosmetic. Most people regain full, pain-free function regardless.
When can I return to sport?
When you have regained full, pain-free movement, strength and confidence, guided by your physiotherapist, rather than by time alone. This lowers the risk of re-injury.
How BeFit Can Help
At BeFit Training Physiotherapy, we assess and treat these injuries and settle your shoulder pain. Our sports physiotherapy team diagnoses the injury, eases the pain and rebuilds your shoulder, if you do need surgery our post-surgical rehabilitation guides your recovery, and return to sport support gets you safely back to the game. Initial consultations run for 45 minutes, one-on-one.
Our team at Edgecliff and Coogee would be glad to help. No referral is required, and HICAPS is available on-site for immediate health fund claiming.
Book an appointment at BeFit Training Physiotherapy — no referral needed.
Edgecliff: (02) 9327 7749 | Coogee: (02) 7205 2805 | befittrainingphysio.com/book-now
Related Services at BeFit
Learn more about how our team can help:
Sports Physiotherapy
Post-Surgical Rehabilitation
Return to Sport
Further Reading
How to Ease Shoulder Pain That’s Worse at Night
How to Recover From Frozen Shoulder: The 3 Stages Explained
References
Beitzel K, et al. ISAKOS upper extremity committee consensus statement on the need for diversification of the Rockwood classification for acromioclavicular joint injuries. Arthroscopy. 2014.
Frank RM, et al. Acromioclavicular joint injuries: evidence-based treatment. J Am Acad Orthop Surg. 2019.
Australian Physiotherapy Association. Clinical guidelines. physiotherapy.asn.au.
