This is the joint between the shoulder blade (Acromion ) and the collar bone (clavicle). the main ligaments which control this joint are actually 2 cms nearer the midline, with minor ligaments at the margins of the joint itself.

The major problems related to this joint include:

1. instability or rupture of the ligaments (often called dislocated A/C joint)
2. arthritis of the A/C joint