acromioclavicular joint

acromioclavicular joint A gliding joint located between the acromion (a projection of the scapula that forms the point of the shoulder) and the clavicle (the collar bone). It is served and supported by the capsular, superior, and inferior acromioclavicular ligaments; the articular disk; and the coracoclavicular (trapezoid and conoid) ligaments. Abbreviated AC joint.