The pectoralis minor muscle is the smaller of the two sets of muscles that connect the bones of the chest to the shoulder and upper arm. Sitting in the axilla and largely below the pectoralis major, the thin pectoralis minor muscle fastens to the shoulder blade (scapula) at the coracoid process and connects it to the center of each side of the chest near the cartilage of the middle ribs (anterior, Continue Scrolling To Read More Below...