AC Joint Sprain

Acromioclavicular Joint

AC Joint pain and shoulder separation

AC joint pain physiotherapy can help if the top of your shoulder feels sore, sharp, or unstable after a fall, tackle, or heavy lifting. An AC joint sprain is often called a shoulder separation. Many people confuse it with a shoulder dislocation, but they are different injuries.

This page explains what the AC joint does, how injuries happen, and what rehabilitation often looks like. It also covers timeframes and return-to-sport steps so you can plan your recovery with confidence.

If your symptoms spread beyond the top of the shoulder, read our guide to shoulder pain physiotherapy. You may also find these related pages useful: rotator cuff tear, shoulder bursitis, and sports injuries.

When to get checked urgently

• Severe pain after a fall or collision
• Obvious deformity, a large “step”, or rapid swelling
• Numbness, tingling, or weakness down the arm
• Inability to lift the arm at all
• Concern for fracture or dislocation

What is the AC joint?

The AC joint sits at the top of your shoulder, where the clavicle (collarbone) meets the acromion (part of your shoulder blade). It helps your arm move overhead and across your body. It also transfers force from your arm into your trunk.

Several ligaments support the joint. If they stretch or tear, the joint can become painful or unstable. A higher-grade injury may create a visible bump on the top of the shoulder.

How AC joint injuries happen

Most AC joint sprains occur after a direct blow to the point of the shoulder. Common examples include a bike crash, a fall onto the side of the shoulder, or a tackle. Another mechanism involves falling onto an outstretched hand, where force travels up the arm and stresses the AC joint.

Common symptoms

• Pain right on the top of the shoulder
• Pain with lifting, pushing, or pressing
• Pain with cross-body movements, like reaching across to a seatbelt
• Swelling and bruising (sometimes)
• In higher-grade injuries, a visible bump or “step”

Grades and classification

Clinicians often describe AC joint injuries by grade (or “type”). Lower grades usually involve sprain of the AC ligaments with the joint mostly aligned. Higher grades involve more disruption and can include the coracoclavicular ligaments as well.

Importantly, your symptoms and goals matter. A small deformity can still settle well with the right rehab plan. In contrast, some people with less obvious deformity still struggle if they return to heavy lifting too soon.

Diagnosis

A physiotherapist will ask about how it happened, what movements trigger pain, and what tasks you need to get back to. The assessment usually includes shoulder range of motion, strength, and joint stability tests.

Sometimes imaging helps. X-rays can check alignment and rule out fracture. Your clinician may recommend additional imaging if they suspect other shoulder injury, such as a rotator cuff tear.

What physiotherapy can do

Rehabilitation usually follows a staged plan. First, you settle pain and protect the joint. Next, you restore comfortable movement. Finally, you rebuild strength and load tolerance so the AC joint handles work, gym, and sport demands.

Your plan may include:

• Pain reduction strategies and activity modification
• Shoulder and shoulder-blade control drills
• Progressive strengthening of deltoid, rotator cuff, and scapular muscles
• Guidance for returning to pressing, overhead work, and contact sport
• Advice about braces, strapping, and training load

Early management you can start today

• Reduce aggravating loads for a short period (heavy pressing, dips, push-ups, overhead work)
• Keep gentle movement going within comfort
• Use ice or heat if it helps symptoms
• Support the arm if walking increases pain

If you suspect ligament damage, a physiotherapist can also discuss how this differs from a ligament tear elsewhere in the body, and what that means for loading progressions.

Exercises and strengthening

Most people benefit from targeted shoulder strengthening once the initial pain settles. Start light and progress slowly. Your physiotherapist will tailor exercise selection and dosage based on injury grade, pain, and goals.

For a safe starting point, see our shoulder exercises page and then progress to gym-based strengthening when your shoulder tolerates it.

How long does recovery take?

Timeframes vary. Many mild sprains improve over a few weeks with good load management. Higher-grade injuries can take longer, especially if your job involves lifting or your sport involves contact or heavy pressing.

As a guide, many people return earlier with lower-grade injuries and later with higher-grade injuries. A physiotherapist can help set realistic checkpoints based on pain, strength, and function rather than relying on time alone.

Return to gym and work

Return to lifting works best when you rebuild the basics first. Start with pain-free range, then light resistance, then controlled pressing patterns, and finally heavier loads. Avoid testing max strength early.

If your job is physical, your plan should include work-specific training. That may involve lifting mechanics, overhead tolerance, and endurance work so you can handle longer shifts without flare-ups.

Return to sport

A staged return reduces setbacks. Your physiotherapist will usually look for:

• Comfortable full range of motion (or near full)
• Good shoulder-blade control under fatigue
• Strength close to the uninjured side for key movements
• Sport-specific tolerance (throwing, tackling prep, falls training, pressing)
• Confidence in contact or impact tasks where relevant

Shoulder Posture Braces

Some people find that reducing load across the AC joint helps in the early phase, especially for desk work or light activity. A posture brace may provide support while symptoms settle. It is not a “fix”, but it can help you manage irritation while you build strength.

More information: Shoulder Posture Brace

Surgery: when is it considered?

Some higher-grade injuries or persistent instability may need an orthopaedic review. Surgery is not required for everyone. A clinician will weigh injury grade, work demands, sport type, cosmetic concerns, and your symptoms over time.

If surgery occurs, rehabilitation still matters. Post-operative physiotherapy focuses on regaining movement, restoring strength, and progressing to work and sport demands in a structured way.

Preventing future AC joint flare-ups

• Build shoulder and upper back strength progressively
• Improve control of the shoulder blade during pressing and overhead activity
• Increase training loads gradually, especially pressing volume
• Keep contact sport return gradual and planned

What to do next

If you suspect an AC joint sprain, book an assessment. A physiotherapist can confirm the likely injury grade, rule out other shoulder injuries, and build a plan that matches your sport, work, and timeline goals.

People also ask

Is AC joint pain serious?
AC joint pain often relates to overload, a fall, or contact injury. Many cases settle with early protection and then progressive strengthening. Get assessed sooner if pain persists, the joint feels unstable, you notice a visible step, or you cannot lift your arm normally.

Can I still train with an AC joint sprain?
Often yes, but you may need to modify pressing and overhead work early. A physiotherapist can help you keep training with safer options while the joint settles.

Why does the bump stay on my shoulder?
A bump can remain if the joint position changes after a higher-grade injury. Many people still return to sport and lifting. Your rehab plan should focus on function, strength, and tolerance.

Related Articles

1. Shoulder Pain: A broad overview of shoulder conditions and common causes of pain.
2. Rotator Cuff Tear: Causes, symptoms, and treatment options for rotator cuff injuries.
3. Effective Shoulder Impingement Treatment And Advice: Common signs and treatment options for shoulder impingement.
4. Shoulder Bursitis Treatment, Physio & Helpful Tips: Helpful guidance for bursitis-related shoulder pain.

References

1. de Groot C, et al. Management of acromioclavicular injuries – current concepts. J Clin Med. 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC9940602/
2. Ma Y, et al. Surgical advances in the treatment of acromioclavicular joint dislocation. J Clin Med. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11577671/
3. Vossen RJM, et al. Choice of acromioclavicular dislocation treatment should not be based on osteoarthritis risk: systematic review. J Clin Med. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11365602/
4. Garcia AV, et al. Reliability of the ISAKOS modification to subclassify acromioclavicular injuries. Orthop J Sports Med. 2022. https://pmc.ncbi.nlm.nih.gov/articles/PMC9772956/
5. Sciascia A, et al. Acromioclavicular joint injuries: clinical commentary with practice considerations. Int J Sports Phys Ther. 2022. https://ijspt.org/wp-content/uploads/2022/03/21-Scascia.pdf