The acromioclavicular joint (commonly referred to as the AC joint) is the joint where the collar bone meets the spine of the shoulder blade at the tip of the shoulder. It is the knob at the top of your shoulder. It is supported by ligaments and muscles in the area. It plays an important role in shoulder movement as the collar bone pivots on the sternum to allow for shoulder movements to occur.


Injury at the AC joint can range from pain, swelling, irritation of the ligaments that support the joint to varying degrees of tearing of the ligaments and fractures of the collar bone or shoulder blade. It is divided into 6 different grades. The severity of the injury determines whether surgery is needed or if it can rehabilitated conservatively.


How is the acromioclavicular joint injured?

  • Fall landing on outstretched hand
  • Fall landing on shoulder


Signs and symptoms of AC joint tears

  • Pain at the tip of the shoulder
  • Pain with raising the arm above shoulder height
  • Pain while pressing your hands together or bearing weight through your hands
  • The knob may be more prominent after injury or there may be a step deformity present


How can Physiotherapy help?

Your Physiotherapist will be able to:

  • Diagnose the injury
  • Give advice as to whether further scans may be needed
  • Help you identify aggravating activities
  • Help you identify positions of comfort
  • Provide manual therapy to reduce pain and overactivity in muscles around your shoulder
  • Guide you through strengthening and scapular stabilisation exercises
  • Help identify if a surgical consult is required
  • Post- operative rehabilitation if you underwent AC joint surgery