Human Movement Science & Functional Anatomy of the:

Subclavius

by Brent Brookbush DPT, PT, MS, PES, CES, CSCS, ACSM H/FS

 

The Subclavius Muscle - http://upload.wikimedia.org/wikipedia/commons/3/32/Subclavius_muscle_frontal3.png

 

What’s in a name

  • Clavicle – Etymology: L, clavicula, little key (Medical Dictionary)
  • Sub -  word-forming element meaning "under, beneath; behind; from under; resulting from further division," from Latin preposition sub "under, below, beneath, at the foot of," also "close to, up to, towards;" of time, "within, during;" figuratively "subject to, in the power of;" also "a little, somewhat" (as in sub-horridus "somewhat rough"). (Etymology Online)

    • Muscle under the key-shaped bone

 

Origin of Subclavius - http://upload.wikimedia.org/wikipedia/commons/3/3d/Gray115.png

Origin: Attaches to the junction of the first rib with its cartilage, by a short thick tendon (8, 11).

Insertion: Inferior surface of middle 1/3 of clavicle in the "subclavian groove" (8, 11).

Insertion of Subclavius - http://upload.wikimedia.org/wikipedia/commons/f/f0/Gray201.png

Nerve: Subclavian nerve, arsing from the the junction of nerve roots C5 and C6 (11).

Note the "nerve to subclavius" originating from the junction of nerve roots C5 & C6 - http://upload.wikimedia.org/wikipedia/commons/thumb/0/0e/Brachial_plexus_2.svg/864px-Brachial_plexus_2.svg.png

 

Action:

  • Clavicle:  Anterior rotation, protraction and depression of the clavicle (8, 11)

    • In quadrupeds this muscle is larger and plays an important role in stabilization of the shoulder girdle for locomotion.  In humans this muscle is a small, secondary muscle (14).
  • Respiration:  The subclavius may aid in forceful inspiration by elevating the first rib (14).

 

Note how the brachial plexus courses under the subclavius, but splits at the pectoralis minor.

 

Relative Location:

  • The subclavius muscle is a deep