Upper limb

Subclavius

Musculus subclavius

Origin

First rib and the adjacent costal cartilage

Insertion

Inferior surface of the clavicle (middle third)

Function

Stabilizes and slightly depresses the clavicle; protects the underlying neurovascular bundle (brachial plexus, subclavian artery/vein)

Innervation

Nerve to subclavius (C5-C6)

Movement & chain

Plays a limited role in depression of the clavicle and stabilization of the sternoclavicular joint during arm movements.

Palpation

Lies beneath the middle third of the clavicle; palpated by pressing superiorly and posteriorly under the clavicle.

Clinical

Protects underlying subclavian vessels and brachial plexus in clavicle fractures; hypertrophy contributes to costoclavicular thoracic outlet syndrome (TOS).

Segmental innervation

C5-C6.

In clinical practice

An anatomical landmark for subclavian vascular puncture and central line placement, where the muscle and the underlying costoclavicular ligament help protect the neurovascular bundle.

Region in the model

Upper limb