Dermatomal Innervation

• A dermatome is an area of skin that is mainly supplied by a single spinal nerve.
• C2-4 innervate the posterior head, neck and shoulder
• C5-T2 innervate the arm
• T2-L1 innervate the thorax and abdomen like a stack of discs

• T6 is at the level of the xiphoid process, T10 is at the horizontal level of the umbilicus

• L2-S4 innervate the legs, progressively moving medio-superiorly, then disto-laterally, then back up to the buttocks