Ligament · Shoulders

Inferior glenohumeral ligament

Ligamentum glenohumerale inferius

The strongest of the three ligaments that thicken the front of the shoulder capsule, and the only one that behaves like a structure rather than a fold. It is best pictured as a hammock: an anterior band and a posterior band with a slack pouch of capsule slung between them, running from the lower rim of the socket and its labrum to the neck of the humerus. When the arm is raised and turned outward — the position of throwing, or of reaching behind you — the hammock swings under the head of the humerus and the front band draws tight across it. In any other position it is loose, which is why the shoulder is free to move at all.