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 levator scapulae and the rhomboid muscles. DSN entrapment is a known, yet relatively uncommon, the cause of neck and/or shoulder pain.[1][2][3]