yogabuch / joints / acromioclavicular joint

Image: Acromioclavicular joint in the context of the shoulder

Acromioclavicular joint (acromioclavicular joint, AC joint)

Joint between the clavicle and the shoulder blade. This joint contains the most wear-prone intervertebral disc in the human body, which is often no longer detectable after the age of 45, although this usually remains asymptomatic. The pathology of the joint mainly involves the (often traumatic) weakening of the ligament structure with dislocation, which is known as acromioclavicular joint dislocation.

Movements in the acromioclavicular joint are always accompanied by movements in the sternoclavicular and scapulothoracic joints. Stable ligaments secure the joint horizontally, primarily through the acromioclavicular ligament, and vertically through coracoclavicular ligaments(coracoclavicular ligament: Lig. trapezoideum ventral lig. Lig. conoideum dorsal).

Articulating bones

• Clavicle
• Shoulder blade

Ligaments

The acromioclavicular joint is secured by three ligaments, for more details see the following links on the page about the shoulder joint:

• Coracoacromial ligament
• Acromioclavicular ligament
• Lig. trapezoideum

Bursae

The bursae of the acromioclavicular joint are described in the shoulder joint, see there.

Tests

Tests of the acromioclavicular joint

Instability of the joint

• definite Two finger test

Tests of the movement directions

Tests of the spanning muscles

Charts

Glenoid (image links to linkmap)

Ligaments (image links to linkmap)

Ligaments (image links to linkmap)