LE Innervations

Question 1

Inferior gluteal nerve motor innervation

Answer 1

L5-S2

motor:
gluteus maximus

Question 2

Superior gluteal nerve motor innervation

Answer 2

L4-S1

motor:
gluteus medius
gluteus minimus
tensor fascia latae

Question 3

Nerve to piriformis motor innervation

Answer 3

Ventral rami of L5-S2

motor:
piriformis

Question 4

Obturator nerve motor innervation (5)

Answer 4

L2-4
passes through obturator canal
Ant/post divisions

motor:
Adductor magnus
Adductor longus
Adductor brevis
Gracilis
Obturator externus

Question 5

Obturator nerve sensory innervation

Answer 5

L2-4

Cutaneous branch of obturator nerve - skin of medial thigh

Question 6

Nerve to quadratus femoris motor innervation

Answer 6

L4-S1

motor:
Gemellus inferior
Quadratus femoris

Question 7

Nerve to obturator internus

Answer 7

L5-S2

motor:
Gemellus superior
Oburator internus

Question 8

Sciatic nerve motor innervation (4)

Answer 8

L4-S3

motor:
Biceps femoris
Semitendinosus
Semimembranosus
Adductor magnus

Question 9

Sciatic nerve injury

Answer 9

Sciatica
- herniated disc or bone spur that compresses the sciatic nerve and cause radiating pain

Piriformis syndrome
- piriformis spasm or tightness compresses the sciatic nerve

Question 10

Femoral nerve motor innervation (7)

Answer 10

L2-4
Passes thru femoral triangle w/ femoral a.

motor:
Iliacus
Pectineus
Sartorius
Rectus femoris
Vastus medialis
Vastus intermedius
Vastus lateralis

Question 11

Femoral nerve sensory innervation

Answer 11

L2-4

medial cutaneous nerve of thigh (branch of ant. div. fem. n.) - skin on medial side lower 2/3 thigh

Intermediate cutaneous nerve of thigh (branch of ant. div. fem. n.) - skin on front of thigh

Saphenous nerve (branch of post. div. fem. n.) - skin on medial side leg

Question 12

Tibial nerve motor innervation (7)

Answer 12

L4-S3
Terminal branch sciatic n.
Branches into medial/lateral plantar nn.

motor:
Gastrocnemius
Soleus
Plantaris

Popliteus
Tibialis posterior
Flexor hallucis longus
Flexor digitorum longus

Question 13

Tibial nerve injury

Answer 13

Tarsal tunnel syndrome
- comprression/irritation of posterior tibial n. by flexor retinaculum

Question 14

Medial plantar nerve motor innervation (4)

Answer 14

L4-S3
Branch of tibial n.

Motor:
Abductor hallucis
Flexor hallucis brevis
Flexor digitorum brevis
Lumbrical 1

Question 15

Lateral plantar nerve motor innervation (6)

Answer 15

L4-S3
Branch of tibial n.

motor:
Plantar interossei
Dorsal interossei
Quadratus plantae
Abductor digiti minimi
Lumbricals 2, 3, 4
Adductor hallucis

Question 16

Tibial nerve sensory innervation

Answer 16

L4-S3??

Tibial n. branch combines w/ common peroneal n. branch to form sural n - skin over lower posterolateral leg

Medial calcaneal branches - skin over heel

Medial plantar n. - skin on medial side of sole

Lateral plantar n. - skin on lateral side sole

Question 17

Deep peroneal nerve motor innervation

Answer 17

L4-S1
Bifurcates from common peroneal n. just below neck of fibula

motor:
Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Extensor digitorum brevis
Peroneus tertius

Question 18

Deep peroneal nerve injury

Answer 18

Foot drop and unopposed eversion during gait

Question 19

Superficial peroneal nerve motor innervation

Answer 19

L4-S2
Bifurcates from common peroneal n. just below the neck of the fibula

motor:
Peroneus longus
Peroneus brevis

Question 20

Deep peroneal nerve sensory innervation

Answer 20

L4-S1

Webbing b/t 1st and 2nd toes of foot on dorsal surface

Question 21

Superficial peroneal nerve sensory innervation

Answer 21

L4-S2

dorsum of foot (except webbing b/t 1st/2nd toes) and anterolateral part of lower leg