Which muscle assists in the downward rotation of the scapula?

The pectoralis minor plays a key role in the downward rotation of the scapula. This muscle, located beneath the pectoralis major, attaches to the coracoid process of the scapula and the third to fifth ribs. When the pectoralis minor contracts, it pulls the scapula forward and downward, contributing to movements such as pushing the shoulders forward and stabilizing the scapula against the thoracic wall. This action is essential during various activities that require stabilization of the shoulder and movement of the upper limb, particularly those that involve downward motions.

The subclavius assists in stabilizing the clavicle but does not directly facilitate downward rotation of the scapula. The serratus anterior primarily contributes to the upward rotation of the scapula and helps in protraction rather than downward rotation. Pectoralis major, while involved in various arm movements, does not have a role in scapular rotation. Thus, the pectoralis minor is the best choice for assisting in the downward rotation of the scapula due to its anatomical positioning and function.