Dermotomes and Myotomes of Lower Extremities

Question 1

L2 Dermatome

Answer 1

Medial thigh-mid-distance

Question 2

L3 Dermatome

Answer 2

Medial knee

Question 3

L4 Dermatome

Answer 3

Medial Malleolus

Question 4

L5 Dermatome

Answer 4

Base of great toe (and lateral aspect leg/plantar aspect to heel)

Question 5

S1 Dermatome

Answer 5

Lateral Heel (base of 5th digit, fibula head, lateral malleolus, little toe)

Question 6

L2 Myotome

Answer 6

Hip Flexion, femoral nerve

Question 7

L3 Myotome

Answer 7

Knee extension, femoral nerve

Question 8

L4 Myotome

Answer 8

Ankle Dorsiflexion, deep fibular nerve

Question 9

L5 Myotome

Answer 9

Great toe extension, long toe extensors, deep fibular nerve

Question 10

S1 Myotome

Answer 10

Ankle Plantar Flexion, tibial nerve

Question 11

L2 Dermatome Key points and peripheral nerve overlap

Answer 11

Obturator Nerve (more medially);
Anterior Cutaneous Branches of Femoral Nerve

Question 12

L3 Dermatome Key points and peripheral nerve overlap

Answer 12

Infrapatellar Branch of Saphenous Nerve

Question 13

L4 Dermatome Key points and peripheral nerve overlap

Answer 13

Medial Crural Cutaneous Branches of Saphenous Nerve

Question 14

L5 Dermatome Key points and peripheral nerve overlap

Answer 14

Deep Fibular Nerve (1st dorsal web space) and Superficial Fibular Nerve

Question 15

S1 Dermatome Key points and peripheral nerve overlap

Answer 15

Sural Nerve