Subclavius muscle
From Wixpert
The subclavius muscle is a muscle of the shoulder located under the
clavicle (collarbone) that depressed the
clavicle to stabilize it during shoulder movements.
Origin
The subclavius originates from the first
rib. Specifically, it attaches at the
costochondral junction of the first
rib.
Insertion
The subclavius muscle inserts at the
clavicle, at the subclavian groove on lower surface of the middle third of the
clavicle.