A dermatome is the area of skin in which the sensory supply is derived from the same spinal nerve root. The lower limb dermatomes are as follows: L1 supplies the inguinal and top of medial thigh. L2 middle and lateral aspect of thigh. L3 covers the medial condyle of femur. L4 for medial malleolus. L5 covers dorsum of foot. S1 covers lateral aspects of calcaneous. S2 covers popliteal fossa. S3 covers gluteal crease And S 4/5 cover perianal region.