AC or acromioclavicular joint sprains are a very common injury in contact sport athletes – accounting for 40-50% of shoulder injuries in contact sports. They also commonly occur in motor vehicle accidents. They usually occur following a fall on the shoulder or elbow.
Basic Anatomy of the Acromioclavicular (AC) Joint
The AC Joint is where the clavicle (collarbone) and acromion process (the highest point of the shoulder blade) meet.
Stability of the AC joint is provided by the joint capsule, the acromioclavicular ligaments and the coracoclavicular ligaments. The acromioclavicular ligament is most frequently injured, but in more severe sprains the coracoclavicular ligaments are also injured.
Sprains can be classified by the following system:
Type 1: Sprain or stretching of acromioclavicular ligament.
Type 2: Full tear of the acromioclavicular ligament +/- partial tear of the coracoclavicular ligament, clavicle is slightly displaced.
Type 3: Full tear of acromioclavicular ligament and coracoclavicular ligaments, significant displacement of clavicle
Type 4: Full tear of acromioclavicular ligament and coracoclavicular ligaments, posterior displacement of clavicle
Type 5: Full tear of acromioclavicular ligament and coracoclavicular ligaments, significant elevation of clavicle
Type 6: Full tear of acromioclavicular ligament and coracoclavicular ligaments, inferior displacement of clavicle.
Type 1&2 are managed conservatively, Type 3 may require surgery and Type 4-6 usually always require surgery.
Physiotherapy Management of AC Injuries
Acute phase:
- Advice regarding whether a sling should be worn, icing and movements that should be avoided
- Tailored exercises to prevent strength loss and work on scapula or shoulder blade control
- Referral for surgical opinion in cases of high-grade injuries
Subacute phase:
- Range of motion exercises
- Scapular control exercises
- Gentle rotator cuff strengthening
- Proprioception exercises
- Functional exercises
- Massage
Return to Work & Sport:
- Advanced strengthening
- Sport/work specific exercises (if relevant)
- Taping advice (if relevant)
- Advice on return to work/sport progression
If you have recently injured your shoulder and would like some guidance with rehabilitation, book an appointment now to receive a diagnosis and tailored treatment plan.
