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Acromioclavicular ligament sprain



  • Injuries to the Acromioclavicular joint is common, 40% of all shoulder injuries can be attributed to the ac-joint 1
  • Injury to the acromioclavicular ligament which is important for the horizontal stability of the joint


  • Usually a result of a fall onto the shoulder, either directly impacting the shoulder, or fall on elbow or straight arm (less likely)
  • If there is too much force exerted onto the adjacent muscles (such as the trapezius and deltoideus), which is sometimes seen in strength training it may exert excessive amount of tension to the ligaments


  • Inferior ligament
    • Is indicates if painful arc is present
  • Superficial ligament
    • Is indicated if there is sensitivity to palpation of the ligament


  • Patient complains of pain after activity
  • There is pain while lying on the affected side
  • One of the few occasions where the patient can pinpoint the location of the injury with a finger
    • If the lower part of the ligament is affected, the pain may radiate into the upper arm, or up towards the trapezius


  • Passive elevation - painful at full range
  • Passive lateral rotation - painful at full range
  • Passive lateral rotation - painful at full range
  • Resisted movements usually painless, but on exceptions can be painful in:
    • Isometric abduction
    • Isometric adduction
  • Painful arc
    • May be present, but not necessarily positive
  • Passive horizontal adduction - clear pain
  • Palpation of the ligament is painful if upper fibres are affected


  • Severe injury to the AC-joint may lead to significant loss of strength and function of the shoulder