Editing Shoulder (section)

===Joint===
{{main|Shoulder joint}}
[[File:Blausen 0797 ShoulderJoint.png|thumb|250px|Cross-section of shoulder joint]]

The [[shoulder joint]] (also known as the glenohumeral joint) is the main joint of the shoulder.<ref name=":0" /> It is a [[ball and socket joint]] that allows the arm to rotate in a circular fashion or to hinge out and up away from the body.  It is formed by the articulation between the head of the humerus and the lateral scapula (specifically-the glenoid cavity of the scapula).  The "ball" of the joint is the rounded, medial anterior surface of the humerus and the "socket" is formed by the glenoid cavity, the dish-shaped portion of the lateral scapula.  The shallowness of the cavity and relatively loose connections between the shoulder and the rest of the body allows the arm to have tremendous mobility, at the expense of being much easier to [[joint dislocation|dislocate]] than most other joints in the body. There is an approximately 4-to-1 disproportion in size between the large head of the humerus and the shallow glenoid cavity.{{citation needed|date=May 2015}}The glenoid cavity is made deeper by the addition of the fibrocartilaginous ring of the [[glenoid labrum]].

The [[joint capsule|capsule]] is a soft tissue envelope that encircles the glenohumeral joint and attaches to the scapula, humerus, and head of the [[biceps]]. It is lined by a thin, smooth [[synovial membrane]].  This capsule is strengthened by the coracohumeral ligament which attaches the coracoid process of the scapula to the greater tubercle of the humerus.  There are also three other ligaments attaching the lesser tubercle of the humerus to lateral scapula and are collectively called the glenohumeral ligaments.{{citation needed|date=May 2015}}

The [[transverse humeral ligament]], which passes from the [[Lesser tubercle of humerus|lesser tubercle]] to the [[greater tubercle of humerus]], covers the [[intertubercular groove]], in which the long head of [[biceps brachii]] travels.{{citation needed|date=May 2015}}