The smaller pectoral muscle, also known as the pectoralis minor, is a muscle located in the upper chest area. It is situated beneath the larger pectoral muscle, known as the pectoralis major. The pectoralis minor is a thin, triangular-shaped muscle that attaches to the front surface of the third, fourth, and fifth ribs, near their cartilages.
This muscle originates from the coracoid process, a bony structure located on the shoulder blade (scapula). From there, it extends downwards and laterally, eventually merging into a flat tendon. This tendon then inserts into the upper portion of the arm bone, known as the humerus.
The main function of the smaller pectoral muscle is to stabilize and position the shoulder blade. It plays a crucial role in various movements of the shoulder girdle, particularly in pulling the shoulder blade downwards and forwards. This action is commonly referred to as scapular depression and protraction. Additionally, the pectoralis minor aids in rotating the shoulder blade, enabling a more optimal position during overhead movements such as throwing or reaching.
Strengthening this muscle is important for maintaining proper posture and shoulder stability, as it helps balance the actions of its larger counterpart, the pectoralis major. Rehabilitation exercises targeting the pectoralis minor are commonly prescribed for individuals experiencing shoulder instability, scapular dyskinesis, or other conditions affecting the shoulder girdle.
