dermatomes

C2

temple, forehead, occiput

C3

neck, posterior cheek, temporal area

C4

shoulder, clavicle and upper scapular area

C5

deltoid area, anterior (entire) arm

C6

anterior arm, radial side of hand (thumb to index finger)

C7

lateral arm and forearm to index, long and ring fingers

C8

medial arm and forearm to long, ring and little fingers

T1

medial side of forearm to base of little finger

T2

medial side of upper arm to medial elbow, pectoral and mid scapular areas

T3-6

upper thorax

T5-7

costal margin

T8-12

abdomen and lumbar region

L1

back, over trochanter and groin

L2

back, front of thigh to knee

L3

back, upper buttock, anterior thigh and knee, medial lower leg

L4

medial buttock, lateral thigh, medial leg, dorsum of foot, big toe

L5

buttock, posterior and lateral thigh, lateral aspect of leg, dorsum of foot, medial half of sole, first, second, and third toes

S1

buttock, thigh and leg posterior

S2

buttock (inc. perineum), thigh and leg posterior

S3

groin, medial thigh to knee

S4

perineum, genitals, lower sacrum