Lower Extremity

Question 1

Obturator N. (nerve roots, 2/5 innervations, injury cause and presentation)

Answer 1

L2-L4
Hip adductors: obturator externus, adductor magnus, longus and brevis
1 knee extensor, gracilis
Pelvic surgery or anterior hip displacement
Decreased medial thigh sensation and decreased adduction

Question 2

Femoral N. (nerve roots, 2/6 innervations, injury cause and presentation)

Answer 2

L2-L4
Hip flexors: iliopsoas (made of psoas and ilacus), pectineus, and sartorius
Also knee extensors: quadriceps (vastus lateralis, rectus femoris, vastus medialis)
Injure with pelvic fracture, decreased thigh flexion and leg extension

Question 3

Common Peroneal N. (nerve roots, injury cause and presentation)

Answer 3

L4-S2

Trauma or compression of lateral aspect of leg or fibular fracture, causes foot drop (steppage gait)

Question 4

Tibial N. (nerve roots, cause of injury and presentation)

Answer 4

L4-S3
Knee trauma, Baker cyst (proximal lesion)
Inability to curl toes and loss of sensation on sole of foot.

Question 5

Superior Gluteal N. (nerve roots, 3 innervations, injury causes and presentation)

Answer 5

L4-S1
Hip abduction and medial rotation: tensor fasciculata, gluteus medius, gluteus minimus
Iatrogenic injury during intramuscular injection to upper medial gluteal region (also polio and posterior hip dislocation)
Trendelenburg sign gait: when stand on ipsilateral leg as lesion, contralateral hip sags

Question 6

Inferior Gluteal N. (nerve roots, innervation, injury cause and presentation)

Answer 6

L5-S2
Hip extension and lateral rotation of thigh, gluteus maximus
Difficulty climbing stairs/rising from seated position because impaired hip extension

Question 7

2 Nerves Controlling Foot

Answer 7

PED - Peroneal Everts and Dorsiflexes, if injured, foot dropPED
TIP - Tibial Inverts and Plantarflexes, if injured, can’t stand on TIPtoes

Question 8

Sciatic Nerve (roots, what it does and splits into)

Answer 8

L4-S3

Innervates posterior thigh (hip extension and knee flexion), splits into common peroneal and tibial nerves

Question 9

Pudendal Nerve (roots, what it innervates and blockage)

Answer 9

S2-S4
Innervates perineum
Can be blocked with LA during childbirth using ischial spine as a landmark for injection

Question 10

Dantrolene

Answer 10

Inhibits Ryanodine Receptor, so treats malignant hyperthermia (overcontraction of muscles caused by using inhaled anesthetics + succinyl-choline (paralyzer))
Also Neuroleptic Malignant syndrome, antipsychotics causing the same thing

Question 11

Type 1 vs. Type 2 Fibers

Answer 11

Type 1 is slow twitch, red, lotsa mt and myoglobin and good at oxphos for sustained contract
Type 2 is opposite. Good at aerobic