The nerve to subclavius (or subclavian nerve) innervates the muscle. The subclavian nerve provides motor innervation to the subclavius muscle. Behind the veins, the nerve to the Subclavius descends in front of the artery. The subclavius moves the shoulder downward and forward. The subclavius depresses the shoulder, carrying it downward and forward. The subclavius is a small triangular muscle, placed between the clavicle and the first rib.