Img 1 : Subclavius Muscle

Muscle Anatomy And Insertions

Subclavius muscle (as the name suggests: sub – under) is a small, triangular muscle located under the clavicle bone. The muscle arises by a short, thick tendon from the first rib in front of the costoclavicular ligament. From this point, the subclavius muscle extends upwards and lateralward to be inserted into the groove on the underside of the clavicle1.

Muscle Function And Innervation

The main function of the muscle is shoulder depression – the muscle draws the clavicle bone downward and forward. Another main function of the muscle is protection – it protects the brachial plexus and major blood vessels which run  under the clavicle bone. The subclavian nerve is responsible fur the muscle innervation.

Muscle Variations

The muscle may insert into the coracoid process (located on the scapula) instead of the groove on the underside of the clavicle.


  • (1912.) Gray H. Muscles Of The Upper Extremity, Anatomy Of The Human Body, page 438.
  • Img 1 source: