Shoulder Separation

August 13th, 2022

Acromioclavicular Joint

  • Acromioclavicular (AC) joint between clavicle (collar bone) and scapula (shoulder blade) is a fibrous union and is stabilized by strong ligaments

Shoulder Separation

  • traumatic in origin and results in various degrees of separation of AC joint
  • grade one separation (most common injury to AC joint): slight displacement (+/- visible) of joint due to stretch or partial tear of a supporting ligament
  • grade two separation: disruption of joint due to partial or complete tear of a supporting ligament
  • grade three separation: dislocation of joint (visible deformity) due to complete tear of supporting ligaments and capsule

Physical Therapy Treatment

  • Grade of AC joint separation determines treatment options; number of treatments required will vary depending on severity of injury -- as a general rule, grade one requires 6-8 visits; grade two requires 20- 30 visits; grade three requires 8-15 visits: reduction of stresses on joint to manage pain and to provide stability while healing; application of ice and electrotherapeutic modalities to reduce inflammation
  • maintenance of flexibility of elbow, wrist, and hand of affected arm shoulder range of motion exercises to tolerance (as permitted by pain)
  • active functional strengthening of all shoulder muscles addressed in late rehabilitation stage (delayed to avoid physical stresses on healing joint structures)
  • stretching and strengthening of rotator cuff muscles (esp supraspinatus muscle) which may have been injured along with AC joint
  • conditioning and functional re-training activities assigned if normal routine of daily living has been negatively impacted

Other Treatments

  • surgical pinning of joint usually not done as shoulder will continue to function even with lack of AC joint congruency


  • grade one sprain: pain is a key indicator for return to activity with usual arm activity resumed over a three-week time frame (return to a contact sport such as rugby or hockey may take longer)
  • grade two injury: may necessitate modification of arm activity for as long as three months (good union of ligament takes time as tissue in this area is not highly vascularized)
  • grade three separation: surgery may be indicated if ultimate functional performance ability is significantly compromised

Physio Note: Joint Protection

Avoid sleeping on injured side

Avoid carrying anything over ten pounds with injured arm as doing so may well delay recovery

Sling support for injured arm may be recommended or provided at outset of your acute care treatment. Your physical therapist may, with grade two separation, choose to tape joint to provide additional support and approximate displaced joint surfaces