Which spinal segments give rise to the dorsal scapular nerve, and what is the consequence of its injury?

• A C5, C6; levator scapulae paralysis alone with no visible deformity
• B C5, C6, C7; serratus anterior paralysis with severe winging on pushing
• C C7, C8; latissimus dorsi paralysis with weak shoulder adduction
• D C5 only; rhomboid paralysis with the scapula displaced laterally and slightly elevated ✓

Explanation

The dorsal scapular nerve arises exclusively from the C5 root, pierces scalenus medius, and descends deep to levator scapulae to supply both rhomboids (and often levator scapulae). Rhomboid weakness allows the scapula to drift away from the midline with slight elevation, producing a mild winging far less dramatic than serratus anterior failure, which is caused by the long thoracic nerve from C5, C6 and C7 and worsens on wall push-up.

Reference: Moore's Clinically Oriented Anatomy, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.