Lower Extremity Nerves

Question 1

Iliohypogastric

Answer 1

T12-L1

Sensory - suprapubic

Motor - transversus abdominus and internal oblique

Injured in ab surgery –> burning in this region

Question 2

Genitofemoral

Answer 2

L1-L2

Sensory - scrotum, labia majora, inner thigh

Motor - cremaster

Injured in laproscopic surgery –> dec thigh sensation below inguinal ligament and loss of cremasteric reflex

Question 3

Lateral Femoral Cutaneous

Answer 3

L2-L3

Sensory - anterior and lateral thigh

Injured by obesity, tight clothing, pregnancy (SUPERFICIAL) –> dec sensation in thigh

Question 4

Obturator

Answer 4

L2-L4

Sensory - medial thigh

Motor - obturator externus, adductor longus, adductor brevis, gracilus, pectineus, adductor magnus

Injured in pelvic surgery –> dec medial thigh sensation and loss of adduction

Question 5

Femoral

Answer 5

L2-L4

Sensory - anterior thigh and medial lower leg

Motor - quads, iliopsoas, pectineus, sartorius

Injured in pelvic fracture –> dec thigh flexion (iliopsoas and pectineus) and dec leg extension (quads)

Question 6

Sciatic

Answer 6

L4-S3

Sensory - posterior thigh

Motor - semitendinous, semimembranous, biceps femoris, adductor magnus

Injured in herniated

Question 7

Common Peroneal

Answer 7

L4-S2 (splits off sciatic)

Sensory - dorsum of foot

Motor - biceps femoris, tibialis anterior, extensors of foot

Injured by fibular neck fracture, compression of lateral leg —> foot drop and loss of dorsum sensation

PED - peroneal everts and dorsiflexes (if injured - foot dropPED)

Question 8

Tibial

Answer 8

L4-S3 (splits off sciatic)

Sensory - sole of foot

Motor - triceps surae, plantaris, popliteus, flexors of foot

Injured by knee trauma, baker cyst (behind knee), tarsal tunnel syndrome –> loss of sensation in sole and cannot invert/plantar flex

TIP - tibial inverts and plantarflexes (if injured - cannot TIPtoe)

Question 9

Superior Gluteal

Answer 9

L4-S1

Motor - gluteus medius, gluteus minimus, tensor fascia latae

Injured by IM injections in upper medial gluteal region (use superolateral quadrant instead to avoid)

Trendelenberg Sign/Gait - wt bearing leg cannot stay aligned when walking on it so hip drops to opposite side as lesion when standing on affected leg

Question 10

Inferior Gluteal

Answer 10

L5-S2

Motor - gluteus max

Injured by posterior hip dislocation –> difficulty rising from chair and climbing stairs and w/ hip extension

Question 11

Pudendal

Answer 11

S2-S4

Sensory - perineum

Motor - external urethral and anal sphincters

Injured in childbirth –> fecal and urinary incontinence plus lack of sensation in perineum / genital area