The medial border of the scapula at the level of the spine is the insertion of which muscle?

• A. Rhomboid major
• B. Levator scapulae
• C. Serratus anterior
• D. Rhomboid minor

Answer: (D)

Understanding where muscles attach on the medial border of the scapula helps you tell apart the rhomboid group. The spine of the scapula marks the upper part of that border, and the rhomboid minor attaches exactly there—originating from the spinous processes of C7 to T1 and inserting along the medial border at the level of the scapular spine. That precise placement distinguishes it from rhomboid major, which inserts lower on the medial border toward the inferior angle. (Serratus anterior attaches to the costal (anterior) surface of the medial border, not the posterior side at the spine level, and levator scapulae attaches higher up at the superior part of the medial border.) So, the muscle that inserts at the medial border at the level of the spine is rhomboid minor. It retracts and stabilizes the scapula and is innervated by the dorsal scapular nerve (C4–C5).