The joint is stabilised by the acromioclavicular ligament, which is comprised of superior, inferior, anterior and posterior components. The superior part of the ligament confers the most stability to the joint. The coracoclavicular ligaments, the conoid and trapezoid, arise from the conoid tubercle and trapezoid line on the lateral part of the inferior surface of the clavicle and insert onto the coracoid process of the scapular, and provide vertical stability to the joint. The joint capsule merges with the fibers of the trapezius muscle, with the deltoid muscles covering the joint superficially. All three structures provide additional stability to the joint. The subacromial bursa is a large bursa that sits under the acromial arch. It can become infected or inflamed, and may require antibiotics, drainage or removal.

The majority of movement that occurs involving the joint, is actually movement of the clavicle or scapula. The joint allows for a large amount of clavicular rotation (40-50 degrees), with the remainder provided by scapular rotation. Movements that occur at the joint are gliding during scapular protraction and retraction, tilting of the acromion and clavicle and rotation during abduction and adduction of the shoulder.

Blood supply: Thoraco-acromial and suprascapular arteries 

Nerve supply: Axillary, suprascapular and lateral pectoral nerves 

Bursae: Subacromial bursa