What it is
The acromioclavicular joint sits at the top of the shoulder where the collarbone meets the acromion. Osteoarthritis in this area causes local pain when reaching across the body, pushing, and sleeping on the shoulder.
Many stay active with strength and load planning. Injections or surgery are options when pain persists.
What happens when it occurs
Cartilage thins, and the joint becomes sensitive to compression and shear. Nearby muscles guard the area, which adds to stiffness. Strength and smart movement reduce stress on the joint.
Common causes and risk factors
- Age-related change and manual work
- Heavy bench press and dips without progression
- Prior AC joint sprain
- Repetitive overhead tasks
Who is most affected
Manual workers and gym users who press frequently. Older adults with a history of AC sprain are also at risk.
Typical symptoms
- Point tenderness over the AC joint
- Pain with cross-body reach and at the top of a press
- Sleep disturbance on the affected side
When to seek care
If pain limits pressing, pushing, or sleeping for more than two weeks.
How we diagnose
Clinical tests, such as cross-body adduction and O'Brien variations. X-rays help when planning injections or surgery.
Management
- Modify pressing angles and volumes
- Strengthen rotator cuff and scapular muscles
- Improve thoracic and shoulder range
- Consider image-guided injection for persistent pain
- Surgical distal clavicle excision for selected cases
Rehabilitation milestones
Phase 1 weeks 0 to 3: settle pain, adjust training, gentle range.
Phase 2 weeks 3 to 8: heavy slow strength and scapular control.
Phase 3 weeks 8 to 16: progressive pressing and work tasks.
Phase 4 months 4 to 6: full return with pain-free range and strength.
Readiness to progress
- Pain trended down during pressing tasks
- Strength symmetry within 90 per cent
- Sleep undisturbed by shoulder pain
Long-term care
- Progress is pressing volumes gradually
- Vary grip width and use landmine or incline options
- Maintain shoulder and thoracic mobility
Australia snapshot
- Common in gym and manual work populations
- Image-guided injections are widely accessible
- Surgical options are available in both public and private settings
Latest insights
Adjust your technique as you build strength. Joint-friendly angles make a difference.
Rotator cuff and scapular control reduce load on the AC joint.


