nerve roots 1/1

Question 1

C1

Answer 1

dermatome: vertex of skull
myotome: (cervical rotation)
reflexes: n/a
paresthesias: n/a

Question 2

C2

Answer 2

dermatome: forehead, temple, occiput
myotome: longus colli, SCM, rectus capitis (shoulder elevation)
reflexes: n/a
paresthesias: n/a

Question 3

C3

Answer 3

dermatome: neck, posterior cheek, temporal area, under mandible
myotome: trap, splenius capitis (shoulder elevation)
reflexes: n/a
paresthesias: cheek, side of neck

Question 4

C4

Answer 4

dermatome: shoulder area, clavicular area, upper scapula area, AC joint
myotome: trapezius, levator scapulae (shoulder elevation)
reflexes: n/a
paresthesias: horizontal band along clavicle and upper scapula

Question 5

C5

Answer 5

dermatome: deltoid area, anterior entire arm to base of thumb
myotome: biceps, supraspinatus, infraspinatus, deltoid (shoulder abduction, elbow flexion)
reflexes: biceps, brachioradialis
paresthesias: n/a

Question 6

C6

Answer 6

dermatome: anterior arm, radial side hand to thumb and index finger
myotome: biceps, supinator, wrist extensors (elbow flexion, wrist extension)
reflexes: biceps, brachioradialis
paresthesias: thumb, index finger

Question 7

C7

Answer 7

dermatome: lateral arm and forearm to index/long/ring fingers
myotome: triceps, wrist flexors (rarely wrist extensors) (elbow extension, wrist flexion)
reflexes: triceps
paresthesias: index, long, ring fingers

Question 8

C8

Answer 8

dermatome: medial arm and forearm to long, ring, and little finger
myotome: ulnar deviators, thumb extensors, thumb adductor, (rarely triceps) (thumb extension)
reflexes: n/a
paresthesias: little finger alone or with adjacent fingers

Question 9

T1

Answer 9

dermatome: medial side forearm to base of little finger
myotome: n/a (finger adduction)
reflexes: n/a
paresthesias: n/a

Question 10

T2

Answer 10

dermatome: medial side upper arm to medial elbow, pectoral and midscapular areas
myotome: n/a
reflexes: n/a
paresthesias: n/a

Question 11

T3-T12

Answer 11

dermatome: 
T3-T6 upper thorax
T5-T7 costal margin
T8-T12 abdomen and lumbar region
myotome: n/a
reflexes: n/a
paresthesias: n/a

Question 12

L1

Answer 12

dermatome: back, over trochanter and groin
myotome: n/a (hip flexion)
reflexes: n/a
paresthesias: groin after holding posture which causes pain

Question 13

L2

Answer 13

dermatome: back, front of thigh to knee
myotome: psoas, hip adductors (hip flexion)
reflexes: n/a
paresthesias: occasional anterior thigh

Question 14

L3

Answer 14

dermatome: medial femoral condyle, back, upper buttock, anterior thigh, anterior knee, medial lower leg
myotome: psoas, quads, thigh atrophy (knee extension)
reflexes: knee jerk sluggish
prone knee bend +
pain on full SLR
paresthesias: medial knee, anterior lower leg

Question 15

prone knee bend test

Answer 15

purpose: neural tension test stressing the femoral nerve and the mid lumbar (L2-L4) nerve roots
procedure: passively flex patient’s knee to end range and hold for 45 seconds, stabilize hip to avoid rotation
+: Pain in
anterior thigh may be tight/strained quadriceps muscle or neural tension of the femoral nerve.
unilateral lumbar area, buttock, or posterior thigh may be lumbar radiculopathy of L2-L3 nerve roots.

Question 16

L4

Answer 16

dermatome: medial malleolus, medial buttock, lateral thigh, medial leg, dorsum of foot, big toe
myotome: tibialis anterior, extensor hallucis (ankle DF) (knee extension, ankle DF)
reflexes: SLR limited
neck flexion pain
weak or absent knee jerk
side flexion limited
paresthesias: medial aspect of ankle

Question 17

L5

Answer 17

dermatome: 3rd MTP joint, buttock, posterior and lateral thigh, lateral aspect leg, dorsum foot, medial half of sole, 1-3rd toes
myotome: extensor hallucis, peroneals, gluteus medius, dorsiflexors, hamstrings and calf atrophy (ankle DF, great toe extension)
reflexes: SLR limited one side
neck flexion painful
ankle decreased
cross leg raising pain
paresthesias: lateral aspect of leg, medial 3 toes

Question 18

S1

Answer 18

dermatome: lateral and plantar foot
myotome: calf and hamstrings, wasting of gluteals, peroneals, plantar flexors (ankle PF)
reflexes: SLR limited
achilles reflex weak or absent
paresthesias: lateral 2 toes, lateral foot, lateral leg to knee, plantar aspect of foot

Question 19

S2

Answer 19

dermatome: popliteal fossa, buttock, thigh, posterior leg
myotome: calf and hamstrings, wasting of gluteals, plantar flexors
reflexes: SLR limited
achilles reflex weak or absent
paresthesias: lateral leg, knee, heel

Question 20

S3

Answer 20

dermatome: ischial tuberosity, groin, posteromedial thigh to knee
myotome: n/a
reflexes: n/a
paresthesias: n/a

Question 21

S4

Answer 21

dermatome: perineum, genitals, lower sacrum
myotome: bladder, rectum
reflexes: n/a
paresthesias: saddle area, genitals, anus, impotence, massive posterior herniation

Question 22

What dermatome is associated with the plantar surface of the foot?

Answer 22

S1

Question 23

Which dermatome would be tested by assessing the area of the middle third of the anterior thigh??

Answer 23

L3

Question 24

Which dermatome would be assessed by touching dorsal surface of the great toe?

Answer 24

L5