Nerve Roots, Myotomes, Dermatomes and DTR

Question 1

C1

Answer 1

Myotome: none

Dermatome: Skull Vertex

DTR: none

Question 2

C2

Answer 2

Myotome: Neck flexion: Rectus Capitus & SCM

Dermatome: Temple, Forehead, occiput

DTR: none

Question 3

C3

Answer 3

Myotome: Neck Side bending: Trapezius and Splenius Capitus

Dermatome: Cheek and Neck

DTR: none

Question 4

C4

Answer 4

Myotome: Shoulder Elevation: Levator Scapula and trapezius.

Dermatome: Clavicle & upper scapula.

DTR: none

Question 5

C5

Answer 5

Myotome: Shoulder ABD: Deltoid, supra/infra, biceps.

Dermatome: Shoulder to anterior arm and forearm to wrist.

DTR: Biceps

Question 6

C6

Answer 6

Myotome: Elbow Flexion and Wrist Extension: Biceps ECRL, ECRB, Supinator

Dermatome: Half of lateral arm to lateral forearm and 1st digit.

DTR: Brachiordialis and extensor digitorum

Question 7

C7

Answer 7

Myotome: Elbow Extension and Wrist Flexion: Triceps, FCU, FCR

Dermatome: Anteriorly just 2nd, 3rd digits. Posterior arm to 2nd and 3rd digits.

DTR: Triceps

Question 8

C8

Answer 8

Myotome: Thumb extension and ulnar deviation: EPL, EPB, FCU, ECU

Dermatome: Anteriorly medial forearm to 4th and 5th digits. Posteriorly the posterior medial arm and forearm.

DTR: Triceps

Question 9

L1

Answer 9

Myotome: None

Dermatome: Back to greater trochanter to inguinal region.

DTR: none

Question 10

L2

Answer 10

Myotome: Hip flexion: Psoas, Illiacus

Dermatome: Back to mid-anterior thigh to groin

DTR: Adductor

Question 11

L3

Answer 11

Myotome: Knee extension: Quadriceps

Dermatome: Back to upper buttock to distal anterior thigh medially (like over VMO)

DTR: None

Question 12

L4

Answer 12

Myotome: Dorsiflexion: Anterior Tibialis

Dermatome: Medial buttock to lateral thigh, corss over patella to medial tibia to big toe

DTR: Patellar

Question 13

L5

Answer 13

Myotome: Great toe extension: Extensor Hallicus Longus

Dermatome: Posterior lateral thigh, lateral leg to dorsum of foot to toes 2, 3 and 4

DTR: None

Question 14

S1

Answer 14

Myotome: Pantar flexion, eversion, knee flexion and hip exentsion.

Dermatome: Posterior/lateral thigh and lateral calve to 5th digit.

DTR: Achillies

Question 15

S2

Answer 15

Myotome: Plantar flexion, knee flexion and hip extension.

Dermatome: Posterior/medial thigh and calve

DTR: Hamstring

Question 16

DTR Grading

Answer 16

0 = Areflexia
1 = Hyporeflexia
2 = Average/normal
3 = Hyperflexia
4 = Clonus/ Markedly hyperactive

Question 17

T1

Answer 17

Myotome: None (Finger ABD and ADD)

Dermatome: Medial Upper arm to middle of forearm.

DTR: None

Question 18

T2

Answer 18

Myotome: None

Dermatome: Axilla

DTR: None