This region contains four muscles that provide movements to the upper limbs or ribs.
It serves to flex, extend, and rotate the humerus, the long bone of the upper arm.
It attaches to the ribs, and serves to stabilize the scapula, the large bone of the shoulder.
The pectoral fascia is a thin layer of tissue over the pectoralis major, extending toward the latissimus dorsi muscle on the back.
It moves the scapula forward around the torso, as when throwing a punch.