The subclavius is important, but for all its importance, it is relatively simple to study because it is simple in function and appearance.
The subclavius is a muscle that starts at the first rib and attaches to the base of the collarbone, as shown in the photo.
The subclavius will perform the function of elevating the ribs and lowering the clavicle.
However, the subclavius is more significant than this movement in that it contributes to the stability of the clavicle and ribs.
This muscle is also associated with ‘rounded shoulders’, which can be caused by weakness in the upper trapezius or overuse of the pectoralis major. ‘Rounded shoulders’ can make the subclavius stiff.