Ligament · Shoulders

Acromioclavicular ligament

Ligamentum acromioclaviculare

The band of fibres thickening the capsule where the outer end of the collarbone meets the acromion — the flat shelf of the shoulder blade felt at the very point of the shoulder. It is a short ligament crossing a small joint, and its fibres run roughly front to back across it, which tells you what it does: it stops the two bones sliding on one another horizontally. Vertical support comes from elsewhere, from the coracoclavicular ligament beneath. A wedge of fibrocartilage is often present inside the joint it covers.