The morphology of the shoulder joint ensures the junction between the trunk and upper limbs. It includes several joints and is the most mobile part of the human body, and this is also why this joint is so unstable.
The shoulder enables the upper limb’s orientation in space, with a wide range of motions on three planes, allowing the hand (its effective extremity) to fulfill its gripping role. It articulates the humeral head with the scapula and the clavicle.
The scapula contains two processes: the acromion, which develops above the humeral head, and the coracoid, which is inside and in front of the acromion process. The humeral head articulates with the shoulder blade’s coil, forming the glenohumeral joint. The scapulothoracic joint complements the glenohumeral joint, allowing the shoulder blade to slide on the posterior chest wall. The collarbone is linked to the shoulder blade by the barely-mobile acromioclavicular joint.
The glenohumeral joint, which is the shoulder’s main articulation, is stabilized by fibrocartilage around the coil, the glenoid lip, and the glenohumeral ligaments.