The shoulder joint, (or glenohumeral joint from Greek glene, eyeball, + -oid, 'form of', + Latin humerus, shoulder), is a multiaxial synovialball and socket joint and involves articulation between the glenoid cavity of the scapula (shoulder blade) and the head of the humerus (upper armbone). Due to the very loose joint capsule that gives a limited interface of the humerus and scapula, it is the most mobile joint of the human body.