Shoulder joint Shoulder joint The shoulder joint (or glenohumeral joint from Greek "glene", eyeball, + -"oid", 'form of', + Latin "humerus", shoulder) is structurally classified as a synovial ball and socket joint and functionally as a diarthrosis and multiaxial joint. It involves articulation between the glenoid cavity of the scapula (shoulder blade) and the head of the humerus (upper arm bone). 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. The shoulder joint is a ball and socket joint between the scapula and the
Bone vessels and cartilage. In the human body at birth, there are over 270 bones, but many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones. The largest bone in the body is the femur or thigh-bone, and the smallest is the stapes in the middle ear. The Greek word for bone is ὀστέον ("osteon"), hence the many terms that use it as a prefix – such as osteopathy. Bone is not uniformly solid, but consists of a flexible matrix (about 30%) and bound minerals (about 70%) which