A patient develops weakness of retraction of the scapula against resistance after a penetrating wound just medial to the scapula. Examination shows the scapula displaced laterally on the affected side. Which nerve and root are involved?

• A Lower subscapular nerve, C5, C6
• B Long thoracic nerve, C5, C6, C7
• C Spinal accessory nerve, cranial nerve XI
• D Dorsal scapular nerve, C5 ✓

Explanation

The dorsal scapular nerve arises directly from the C5 root, passes deep to levator scapulae, and supplies the rhomboids (and usually levator scapulae). Rhomboid paralysis weakens scapular retraction and allows the scapula to drift laterally away from the midline. Long thoracic nerve injury produces winging worsened by pushing against a wall, while spinal accessory injury droops the shoulder and weakens shrugging via trapezius.

Reference: Moore's Clinically Oriented Anatomy, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.