Nerves of the Lower Limb

Question 1

Which 8 spinal nerve roots innervate the lower limb?

Answer 1

L1 - S3

L1-L4 branch within psoas major (hip flexor)
supplies anterior and medial compartments of thigh
- leg extension + adduction

Question 2

Describe the sciatic nerve location

Answer 2

Largest nerve in body
5 branches converge into 1 under piriformus muscle
runs between ischial tuberosity and greater trochanter

Question 3

What does the sciatic nerve supply?

Answer 3

Muscles in posterior thigh
Bifurcates into
- tibial nerve
- common peroneal (fibular nerve)

Question 4

What are the branches of the common peroneal nerve?

Answer 4

winds around neck of fibula
Superficial - plantarflexion of foot (down)
Deep - dorsalflexion (upward)

Question 5

Where is the tibial nerve found?

Answer 5

Arises at popliteal fossa apex and runs through it into the leg

Question 6

Name the calf muscles

Answer 6

Soleus
Gastrocnemius

collectively referred to as triceps surae
tibial nerve supply
attach to achilles tendon

Question 7

What is the role of quadricep muscles?

Answer 7

hip flexion

leg extension

Question 8

Which nerve supplies the quadriceps?

Answer 8

Femoral nerve supplies anterior thigh (quads) and sartorius

Question 9

What does the obturator nerve supply?

Answer 9

medial (adductor) compartment of thigh

Question 10

Summarise the lower limb nerve supply

Answer 10

Sciatic - Posterior - flexion
Femoral - Anterior - extension
Obturator - Medial - adduction