Shoulder joint

Shoulder joint
The right shoulder and shoulder joint
Details
Identifiers
Latin	Articulatio humeri
MeSH	A02.835.583.748
Dorlands /Elsevier	a_64/{{{DorlandsSuf}}}
TA	A03.5.08.001
FMA	25912
Anatomical terminology []

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 humerus. However the socket of the glenoid cavity of the scapula is itself quite shallow and is made deeper by the addition of the glenoid labrum. The glenoid labrum is a ring of cartilaginous fibre attached to the circumference of the cavity. This ring is continuous with the tendon of the biceps brachii above. Normal glenohumeral joint space is 4–5 mm.

Between the associated muscles of the shoulder is an anatomic space called the axillary space which transmits the subscapular artery and axillary nerve.

The shoulder joint has a very loose joint capsule known as the articular capsule of the humerus and this can sometimes allow the shoulder to dislocate. The long head of the biceps brachii muscle travels inside the capsule from its attachment to the supraglenoid tubercle of the scapula.