Which action is performed by rhomboid major?

Which action is performed by rhomboid major?

• A. Rotates glenoid fossa down
• B. Retracts the scapula
• C. Fixes scapula against thoracic wall
• D. Elevates the scapula

Answer: (B)

Rhomboid major primarily pulls the scapula toward the spine, i.e., retracts (adducts) the scapula. Its fibers run from the thoracic vertebrae to the medial border of the scapula, so when it contracts it draws the inner edge of the scapula medially and upward, bringing the shoulder blades closer together. This retraction is what you’re doing when you pinch your shoulder blades. In addition, it can elevate the scapula and downwardly rotate the glenoid, but the most characteristic and defining action is retraction. The other actions are possible but are either secondary or shared with other muscles.

Rhomboid major primarily pulls the scapula toward the spine, i.e., retracts (adducts) the scapula. Its fibers run from the thoracic vertebrae to the medial border of the scapula, so when it contracts it draws the inner edge of the scapula medially and upward, bringing the shoulder blades closer together. This retraction is what you’re doing when you pinch your shoulder blades. In addition, it can elevate the scapula and downwardly rotate the glenoid, but the most characteristic and defining action is retraction. The other actions are possible but are either secondary or shared with other muscles.