Subclavian nerve

The subclavian nerve (a.k.a. the nerve to subclavius muscle) is a small motor nerve that arises from the upper trunk of the brachial plexus, typically from the C5 and C6 nerve roots. It descends anterior to the middle and inferior trunks of the brachial plexus and the subclavian artery, to innervate the subclavius muscle. This muscle, located beneath the clavicle, helps stabilize the sternoclavicular joint.

The subclavian nerve's relatively short course makes it susceptible to injury during clavicular fractures or surgical procedures in the area.

Additional connection with the phrenic nerve

The subclavian nerve primarily innervates the subclavius muscle but often gives rise to the accessory phrenic nerve. This accessory nerve typically joins the phrenic nerve in the thorax, assisting in the diaphragm's innervation. Aside from this contribution via the accessory phrenic nerve, there is no direct connection between the subclavian nerve and the main phrenic nerve.