What is the primary function of the rhomboids in shoulder movement?

The primary function of the rhomboids in shoulder movement is to retract the scapula. The rhomboid major and minor muscles are located between the spine and the scapula, and when they contract, they pull the scapula toward the spine. This action is crucial for various upper body movements, especially those involving pulling actions, such as rowing or pulling the shoulder blades together during exercises like a seated row or during certain phases of overhead lifting.

Retracting the scapula helps to stabilize the shoulder girdle and maintain proper posture, which is essential for effective movement mechanics. In activities that require shoulder stability, the rhomboids' action supports the positioning of the glenohumeral joint (the ball-and-socket joint of the shoulder), allowing for more efficient movement patterns and reducing the risk of injury from improper alignment.