What is the action of the rhomboid minor?

• A. Protracts the scapula
• B. Elevates the ribs
• C. Retracts the scapula and downwardly rotates the glenoid; helps fix scapula to thorax
• D. Abducts the scapula

Answer: (C)

Rhomboid minor mainly pulls the scapula toward the spine (retraction) and rotates the scapula so the glenoid cavity faces downward (downward rotation). It also helps fix the scapula to the thoracic wall, stabilizing it during arm movements. Its fibers run from the vertebrae to the medial border of the scapula, so when it contracts, the medial border is drawn medially and slightly upward, producing retraction and downward rotation. Protracting the scapula or elevating the ribs are actions of different muscles (for example, serratus anterior protracts, while rib elevation involves respiration muscles), so those options don’t describe this muscle’s primary actions.