AC Joint Injuries: What They Are, How They Happen, and How Physiotherapy Can Help.

Shoulder pain after a fall or collision can make even simple activities—like reaching

overhead, getting dressed, or lifting objects—difficult. One common cause of pain at the top

of the shoulder is an acromioclavicular (AC) joint injury, often referred to as a 'shoulder

separation.'

Whether you're an athlete, a weekend warrior, or someone who has taken an awkward fall,

understanding AC joint injuries can help you recover safely and get you back to doing what

you enjoy.

What is the AC Joint?

The acromioclavicular (AC) joint is located at the top of your shoulder, where the collarbone

(clavicle) meets the acromion.

Strong ligaments hold this joint together, allowing your shoulder to move smoothly while

providing stability during lifting, pushing, pulling, and overhead activities.

How Do AC Joint Injuries Occur?

AC joint injuries usually happen after a direct impact to the shoulder. Common causes

include:

• Falling directly onto the point of the shoulder

• Contact sports such as rugby, AFL, football, or hockey

• Cycling or mountain biking accidents

• Skiing or snowboarding falls

• Motor vehicle accidents

The force can stretch or tear the ligaments that stabilise the AC joint, leading to pain and

instability.

Signs and Symptoms

Symptoms can vary depending on the severity of the injury, but often include:

• Pain at the top of the shoulder

• Tenderness over the AC joint

• Pain when lifting the arm overhead

• Difficulty carrying heavy objects

• Swelling or bruising

• A visible deformity on the top of the shoulder in more severe injuries

• Pain when lying on the affected side

  
  

How Are AC Joint Injuries Graded?

AC joint injuries are classified from Grade I to Grade VI based on the amount of ligament

damage. This system is called the “Rockwood Classification System”.

• Grade I

  • Mild ligament sprain

  • No significant instability

  • Usually recovers within 2–4 weeks

• Grade II

  • Partial ligament tear

  • Mild separation of the joint

  • Recovery typically takes 4–8 weeks

• Grade III

  • Complete tear of the AC ligaments with injury to the supporting ligaments beneath

  • Visible deformity may be present

  • Many people recover well without surgery, although some cases may require

    specialist review

• Grades IV–VI

  • More severe injuries involving significant displacement of the collarbone

  • Usually require assessment by an orthopaedic surgeon and may need surgery

    
    

Treatment

The good news is that most AC joint injuries can be managed without surgery.

Early management focuses on:

• Reducing pain and inflammation

• Protecting the injured ligaments

• Gradually restoring shoulder movement

As symptoms improve, rehabilitation progresses to:

• Restoring full range of motion

• Improving shoulder blade control

• Strengthening the rotator cuff and surrounding muscles

• Building shoulder stability

• Returning to work, sport, and everyday activities safely

  
  

Returning to Sport

Returning too soon can increase the risk of ongoing pain or reinjury.

A successful return to sport should include:

• Full shoulder range of motion

• Minimal or no pain

• Strength comparable to the uninjured side

• Ability to complete sport-specific movements confidently

• Clearance from your treating physiotherapist or healthcare professional

Recovery times vary depending on the severity of the injury, but many athletes return

successfully with a structured rehabilitation program.

How We Can Help

At SportsFit, our clinicians provide personalized rehabilitation programs designed to help you

recover safely and confidently.

Your treatment may include:

• Pain management strategies

• Hands-on therapy where appropriate

• Progressive strengthening exercises

• Shoulder stability and control training

• Sport-specific rehabilitation

• Guidance on returning to work, gym, and sport

  
  

Our goal isn't just to reduce your pain—we want to restore your strength, confidence, and

performance while reducing the risk of future shoulder injuries.

Book an appointment with one of our experienced clinicians at SportsFit! We'll assess your

injury, explain your diagnosis, and develop a personalized rehabilitation plan to get you back

to doing what you love!