Which muscle retracts the scapula and pulls it downward?

The trapezius inferior muscle plays a crucial role in scapular movement, particularly in retraction and downward rotation. It is positioned at the lower portion of the trapezius muscle group, which extends across the upper back and neck. When the trapezius inferior fibers contract, they pull the scapula medially (retraction) and also assist in rotating it downwards. This action is significant for various movements that require stabilization and positioning of the shoulder girdle during activities like pulling or lifting.

The rhomboid major, while capable of retracting the scapula, does not play a significant role in its downward movement specifically. The latissimus dorsi primarily contributes to the extension and internal rotation of the shoulder rather than directly influencing the scapula's retraction and downward pull. The serratus anterior is primarily responsible for protracting the scapula and facilitating upward rotation, but not for retracting and pulling it downward. Hence, the trapezius inferior is the most appropriate muscle that fulfills the requirement of both retracting the scapula and pulling it downward.