Anatomy, Shoulder and Upper Limb, Dorsal Scapular Nerve

The dorsal scapular nerve (DSN) is a motor nerve arising from the ventral ramus of the C5 nerve root. Once branching from the brachial plexus, the DSN pierces the middle scalene muscle, coursing deep to the levator scapulae and the rhomboid major and minor muscles. Dorsal scapular nerve entrapment is a known, yet relatively uncommon, cause of neck and/or shoulder pain.