AC Joint Injuries

AC Joint Injuries: What Are They and How Are They Managed?

Acromioclavicular (AC) joint injuries are a common source of shoulder pain—especially in people playing contact sports, lifting heavy overhead, or involved in high-speed falls. If you’ve landed awkwardly in a tackle, taken a heavy knock during contact sport, or suddenly developed pain while pressing at the gym, the AC joint might be involved.

We see a lot of AC joint injuries at The Injury Clinic Physiotherapy, and our physiotherapists are experienced in the management of AC joint presentations.

WHAT IS THE AC JOINT?

The acromioclavicular (AC) joint sits at the top of your shoulder, where the end of the collarbone (clavicle) meets the acromion (part of the shoulder blade). It’s a small joint with a big job—allowing movement between the scapula and clavicle while also providing stability during overhead and cross-body movements.

Although it doesn’t contribute a huge amount of motion, it’s critical in allowing full range of movement and transmitting load through the shoulder. It’s held together by a capsule and two main sets of ligaments: the acromioclavicular ligaments (providing horizontal stability) and the coracoclavicular ligaments (providing vertical stability). When these structures are disrupted—either traumatically or gradually over time—an AC joint injury develops.

HOW DO AC JOINT INJURIES OCCUR?

There are a few key ways that AC joint injuries tend to occur, and they usually fall into one of two categories: traumatic or overuse.

Traumatic injuries typically happen from a direct blow to the point of the shoulder—common in sports such as football, rugby or motocross. These injuries often occur suddenly and are associated with pain, swelling, and sometimes a visible deformity.

Overuse or degenerative injuries are more common in gym-goers or manual workers. Repetitive loading of the joint—such as during bench press, overhead pressing, or dips—can irritate the joint over time.

These injuries are more common in young, physically active males, though they can occur across a range of age groups depending on exposure and load.

CLASSIFICATION OF AC JOINT INJURIES:

AC joint injuries are typically classified using the Rockwood system, which categorises them from Type I through to Type VI based on the severity of ligament damage and joint displacement:

Type I: A mild sprain with partial damage to the AC ligament and no visible displacement.
Type II: Complete disruption of the AC ligament and sprain of the coracoclavicular ligaments, with minor displacement.
Type III: Both the AC and coracoclavicular ligaments are ruptured, resulting in visible dislocation of the joint.
Type IV-VI: High-grade dislocations with significant displacement, often involving tearing of surrounding muscle and soft tissue. These are typically seen in high-impact trauma.

Most of the injuries we see at The Injury Clinic fall into the Type I–III range. Types I and II are almost always managed non-operatively with great success. Type III injuries can vary. Some people recover really well with conservative management, while others may need to consider surgical options based on their sport, work, or goals. Higher-grade injuries (Types IV-VI) are much less common and generally require surgical consultation and management.

SYMPTOMS OF AC JOINT INJURY:

Symptoms can vary depending on the type and severity of the injury, but the most common complaints we see at The Injury Clinic include:

Pain at the top of the shoulder, particularly with overhead movements or reaching across the body.
Swelling or tenderness around the joint.
A visible “step” deformity, especially in higher-grade injuries.
Pain when lying on the injured side, which can disrupt sleep.
A feeling of instability or clicking, particularly with movements like bench press, push-ups, or pressing overhead.
In acute traumatic injuries, the pain is often sharp and immediate. In more chronic or degenerative cases, it may present more like a dull ache or pinching sensation with activity.

MANAGEMENT STRATEGIES AT THE INJURY CLINIC PHYSIOTHERAPY

How we manage AC joint injuries depends on a range of factors: the type and severity of the injury, the person’s activity level and goals, and how irritable the shoulder is in the early stages. At The Injury Clinic Physiotherapy, our physiotherapists typically break down management into short-term and long-term phases.

Short-Term Management:

Load Management: Early on, we look to modify or reduce aggravating activities. That usually means avoiding overhead and cross-body movements for a short time to allow the joint to settle.
Taping/Bracing: Taping the AC joint can provide support, reduce pain, and help with postural positioning while the joint heals.
Pain Relief: Soft tissue release, dry needling, ice, and short-term NSAID use (after 48–72 hours) may help reduce pain and inflammation.
Education: One of the most important parts—helping you understand the injury, what to expect, and how we’re going to get you back to full activity.

Long-Term Management:

Strength Rehab: Once the pain has settled, we gradually reintroduce loading through the shoulder, with a focus on rotator cuff, scapular stabilisers, and upper limb strength.
Movement Quality: Addressing biomechanics, especially around pressing and overhead movement, is key to long-term success.
Return to Sport or Gym: A gradual, structured return is critical—especially in sports with high shoulder demands like football, swimming, or CrossFit.

WHAT DOES THE RESEARCH SAY?

There’s been a lot of discussion over the years about whether surgical or conservative management is better for AC joint injuries—particularly for Type III injuries. Generally speaking, Type I-II are almost always managed conservatively, with Type IV and V traditionally treated operatively. However, ongoing discussion remains about whether surgical or conservative management is better for Type III AC joint injuries. Recent studies help clear up some of that debate:

A recent systematic review by Bianco Prevot et al. (2025) found no significant difference in outcomes between surgical and non-surgical treatment for Type III injuries, although surgical cases had better anatomical alignment on imaging.

A meta-analysis from Xie et al. (2024) reported similar findings, concluding that conservative management produced similar functional results to surgery with fewer complications for individuals who had experienced Type III injuries.

So, while surgery has its place—particularly in high-grade injuries—most people with Type I–III injuries do very well with a well-structured and individualised rehab plan.

FINAL THOUGHTS

AC joint injuries are common—but with the right diagnosis, guidance, and rehab plan, most people return to full function without long-term issues. Whether you’ve had a recent knock or long-standing shoulder pain during pressing, it’s worth getting it looked at properly. We welcome AC joint injury presentations at The Injury Clinic Physiotherapy. Let our Geelong-based physiotherapists work with you to get you back doing the things you love.

References:

Bianco Prevot, L., Accetta, R., Fozzato, S., Moroder, P., & Basile, G. (2025). Surgical vs conservative: what is the best treatment of acute Rockwood III acromioclavicular joint dislocation? A systematic review and meta-analysis. EFORT Open Reviews, 10(3), 141–150. https://doi.org/10.1530/eor-2024-0077

Xie, C., Fan, S., Chen, L., Huang, L., Chen, C., & Luo, H. (2024). Comparative efficacy of operative versus conservative treatment for Rockwood type III acromioclavicular joint dislocation: a systematic review and meta-analysis of randomized controlled trials. BMC Musculoskeletal Disorders, 25(1). https://doi.org/10.1186/s12891-024-08100-x