Acromioclavicular joint (ACJ) conditions
Typically pain arising from the ACJ produces well localised pain on top of the shoulder though rarely it may mimic other shoulder problems. The most common injury arises from a direct blow on the angle of the shoulder which may lead to ACJ dislocation, inflammation and early onset osteoarthritis.
Heavy weights, especially bench pressing, puts a significant shearing stress on the ACJ which can lead to chronic shoulder pain. Imaging reveals very specific changes to the end of the clavicle known as Distal Clavicular Osteolysis (DCO). Offloading the shoulder combined with scapular retraining may help but often surgery is required to definitively treat this condition.