Dermatomes, Myotomes, & Reflexes

Question 1

Dermatome: L1

Answer 1

Groin

Question 2

Dermatome: L2

Answer 2

Anterior proximal thigh

Question 3

Dermatome: L3

Answer 3

Medial aspect of distal thigh and knee

Question 4

Dermatome: L4

Answer 4

Lat aspect of knee and Medial distal leg

Question 5

Dermatome: L5

Answer 5

Dorsum of foot

Question 6

Dermatome: S1

Answer 6

Lateral foot

Question 7

Dermatome: S2

Answer 7

Medial aspect of heel

Question 8

Myotome: L2

Answer 8

Hip Flexion (Psoas)

Question 9

Myotome: L3

Answer 9

Knee Extension (Quads) – slightly bent

Question 10

Myotome: L4

Answer 10

DF/ Inv (Anterior Tibialis) – pull down and out; stab laterally

Question 11

Myotome: L5

Answer 11

Toe Extension (EHL and EDL)

Question 12

Myotome: S1

Answer 12

Gastrocnemius/soleus; Eversion (Peroneals) – pull in

Question 13

Myotome: S2

Answer 13

Toe Flexion (FDL)

Question 14

Reflex: L3

Answer 14

Patellar Tendon – back of hammer

Question 15

Reflex: L4

Answer 15

(Patellar Tendon)

Question 16

Reflex: L5

Answer 16

Medial Hamstring Tendon – on semitendinosus

Question 17

Reflex: S1

Answer 17

Achilles Tendon – slight dorsiflexion

Question 18

Dermatome: Groin

Answer 18

L1

Question 19

Dermatome: Anterior proximal thigh

Answer 19

L2

Question 20

Dermatome: Medial aspect of distal thigh and knee

Answer 20

L3

Question 21

Dermatome: Lat aspect of knee and Medial distal leg

Answer 21

L4

Question 22

Dermatome: Dorsum of foot

Answer 22

L5

Question 23

Dermatome: Lateral foot

Answer 23

S1

Question 24

Dermatome: Medial aspect of heel

Answer 24

S2

Question 25

Myotome: Hip Flexion (Psoas)

Answer 25

L2

Question 26

Myotome: Knee Extension (Quads) – slightly bent

Answer 26

L3

Question 27

Myotome: DF/ Inv (Anterior Tibialis) – pull down and out; stab laterally

Answer 27

L4

Question 28

Myotome: Toe Extension (EHL and EDL)

Answer 28

L5

Question 29

Myotome: Gastrocnemius/soleus; Eversion (Peroneals) – pull in

Answer 29

S1

Question 30

Myotome: Toe Flexion (FDL)

Answer 30

S2

Question 31

Reflex: Patellar Tendon

Answer 31

L3/L4

Question 32

Reflex: Medial Hamstring Tendon/Semitendinosus

Answer 32

L5

Question 33

Reflex: Achilles Tendon

Answer 33

S1

Question 34

Dermatome: C2

Answer 34

Side of head

Question 35

Dermatome: C3

Answer 35

Anterior and lateral neck

Question 36

Dermatome: C4

Answer 36

Supraclavicular area/Over trap

Question 37

Dermatome: C5

Answer 37

Lateral Arm

Question 38

Dermatome: C6

Answer 38

Pad of thumb

Question 39

Dermatome: C7

Answer 39

Pad of index/middle finger

Question 40

Dermatome: C8

Answer 40

Hypothenar eminence and 5th finger

Question 41

Dermatome: T1

Answer 41

Medial forearm

Question 42

Myotome: C1

Answer 42

Rectus Capitis Anterior and lateral (flexion)

Question 43

Myotome: C2

Answer 43

Rectus Capitis Posterior (extension)

Question 44

Myotome: C3

Answer 44

Scalenes; Erector Spinae (side bend)

Question 45

Myotome: C4

Answer 45

Scapular elevation (Upper trapezius; levator scapulae)

Question 46

Myotome: C5

Answer 46

Shoulder abduction/Middle deltoid OR Elbow Flexion/Biceps

Question 47

Myotome: C6

Answer 47

Extensor Carpi Radialis/Wrist extension (Pressure down and out)

Question 48

Myotome: C7

Answer 48

Triceps (elbow extension)

Question 49

Myotome: C8

Answer 49

Thumb Extension (EPL)

Question 50

Myotome: T1

Answer 50

Finger adduction (PAD)

Question 51

Reflex: C4

Answer 51

Levator Scapulae

Question 52

Reflex: C5

Answer 52

Deltoid

Question 53

Reflex: C6

Answer 53

Biceps

Question 54

Reflex: C7

Answer 54

Triceps

Question 55

Reflex: C8

Answer 55

Long Finger Flexors

Question 56

Dermatome: Side of head

Answer 56

C2

Question 57

Dermatome: Anterior and lateral neck

Answer 57

C3

Question 58

Dermatome: Supraclavicular area/Over trap

Answer 58

C4

Question 59

Dermatome: Lateral Arm

Answer 59

C5

Question 60

Dermatome: Pad of thumb

Answer 60

C6

Question 61

Dermatome: Pad of index/middle finger

Answer 61

C7

Question 62

Dermatome: Hypothenar eminence and 5th finger

Answer 62

C8

Question 63

Dermatome: Medial forearm

Answer 63

T1

Question 64

Myotome: Rectus Capitis Anterior and lateral (flexion)

Answer 64

C1

Question 65

Myotome: Rectus Capitis Posterior (extension)

Answer 65

C2

Question 66

Myotome: Scalenes; Erector Spinae (side bend)

Answer 66

C3

Question 67

Myotome: Scapular elevation (Upper trapezius; levator scapulae)

Answer 67

C4

Question 68

Myotome: Shoulder abduction/Middle deltoid OR Elbow Flexion/Biceps

Answer 68

C5

Question 69

Myotome: Extensor Carpi Radialis/Wrist extension (Pressure down and out)

Answer 69

C6

Question 70

Myotome: Triceps (elbow extension)

Answer 70

C7

Question 71

Myotome: Thumb Extension (EPL)

Answer 71

C8

Question 72

Myotome: Finger adduction (PAD)

Answer 72

T1

Question 73

Reflex: Levator Scapulae

Answer 73

C4

Question 74

Reflex: Deltoid

Answer 74

C5

Question 75

Reflex: Biceps

Answer 75

C6

Question 76

Reflex: Triceps

Answer 76

C7

Question 77

Reflex: Long finger flexors

Answer 77

C8

Question 78

Reflex Grading

0

1+

2+

3+

4+

Answer 78

0 = no response

1+ = low normal (present, depressed)

2+ = normal

3+ = possible abnormal (brisk)

4+ = abnormal (very brisk)

Question 79

Reflex Mechanism (5)

Answer 79

1. Tap tendon
2. Stretches muscle
3. Spindle feel stretch
4. Sensory 1a fibers send signal to spinal cord
5. Motor neuron in spinal cord tells muscle to contract

* Simple reflex response - doesn’t travel to brain

Question 80

Abnormal response: Too much/hyper

Answer 80

Upper motor neuron lesion

Question 81

Abnormal response: Too little/hypo

Answer 81

Lower motor neuron lesion

Question 82

T/F: To determine if it is too much/little of a response is based on average response times.

Answer 82

False: key is symmetry

abnormal = asymmetric response bilaterally

normal = symmetric response bilaterally

Question 83

Dermatome Diagram

Answer 83