Subclavius is a small muscle that arises from the costochondral junction of the first rib and is inserted into the subclavian groove on the inferior surface of the clavicle. Together with the pectoralis major and pectoralis minor, the subclavius form the anterior wall of the axilla.
Subclavius Origin and Insertion
The subclavius muscle originates by a short thick tendon from the junction of the 1st rib and its costal cartilage as the fleshy fibers move obliquely superolaterally and inserts at the inferior surface of the middle third of clavicle.
The subclavius is innervated by the subclavian nerve (C5, C6) this arises from the upper trunk of the brachial plexus.
Subclavius Action and Function
The subclavius anchors and depresses the clavicle. This muscle assists in stabilizing the clavicle in movements of the pectoral girdle and may also prevent the jagged ends of a fractured clavicle from damaging the adjacent subclavian vein.