neurology of lower limb

Question 1

How to test lower limb nerve injuries

Answer 1

Spinaal root-dermatomes, myotomes

peripheral nerves-cutaneous branches, motor branches

Question 2

Draw legs and shade in where each nerve distributed to and state its derivations

Answer 2

ref. notes

Question 3

List where lower limb flexors and extensors derive from

Answer 3

Hip: flexor L2,3 extenror, L4,5
Knee extensor L3,L4, flexor L5, S1
Ankle: extensor, L4, L5, flexor S1, S2
Foot: inversion L4,5 Eversion L5, S1, intrinsic S2

Question 4

Lumbar plexus draw

Answer 4

ref. notes 1,2,1,2,2,3,3 SIIGLOF T12-L4

Question 5

Femoral nerve derivation and function

Answer 5

Derivation: L2-4
Motor Functions: Innervates the muscles: Illiacus, pectineus, sartorius, all the muscles of quadriceps femoris.
Sensory Functions: Innervates the skin on the anterior thigh and the medial leg.

Question 6

Obturator nerve derivation and functionss

Answer 6

Derivation: L2-4
Motor Functions: Innervates the muscles: obturator externus, pectineus, adductor longus, adductor brevis, adductor magnus, gracilis.
Sensory Functions: Innervates the skin over the medial thigh.

Question 7

Why do you get referred pain in hips and knees

Answer 7

Hip and knee shares common innervations (femoral and obturator nerves) so pain referred from hips to knees vice versa

Question 8

Lateral femoral cutaneous nerve derivation and what happens if damaged

Answer 8

Derivation: L2-3
Damaged: paraesthesisa (pins and needles sensation)+pain, burning sensation

Question 9

Sacral plexus from where to where, list derivations for tibial, common peroneal, superior gluteal, inferior gluteal, post cutaneous nerve of thigh, piriformis

Answer 9

L4-S3
Tibial (L4-S3) anterior division
common peroneal (L4-S2) posterior division
superior gluteal (L4-S1) posterior division
Inferior gluteal (L5-S2) posterior divission
Post cutaneous nerve of thigh (S2-3) direct
Piriformis (S1-2) direct

Question 10

What do the gluteal nerves motor supply and state its derivations

Answer 10

Superior gluteal (L4-S1): gluteus medius, gluteus minimus, tensor fascia lata, hip joint
Inferior gluteal (L5-S2): gluteus maximus
NB no sensory function

Question 11

What does the sciatic nerve split into

Answer 11

tibial nerve and common fibular nerve (on deep level) NB posterior cutaneous nerve runs superficial to it

Question 12

How to test for sciatica

Answer 12

Legs up and straight and lie down to then dorsi flex foot to see if shooting pain (caused by stretching sciatic nerve) important to do wihtout bending knees because it shows how the tibial and peroneal branch arise from scciatic

Question 13

What happens if tibial nerve damaged

Answer 13

sensory loss in solle of foot

Question 14

How to damage common peroneal nerve

Answer 14

fracture neck of fibula

Question 15

What is the root and the sensory and motor functions of the sciatic nerve

Answer 15

L4-S3
Sensory Functions:
Tibial portion: Innervates the skin on the posterolateral and medial surfaces of the foot as well as the sole of the foot.
Common fibular portion: Innervates the skin on the anterolateral surface of the leg and the dorsal aspect of the foot.
Motor Functions:
Tibial portion – Innervates the muscles in the posterior compartment of the thigh (apart from the short head of the biceps femoris), and the hamstring component of adductor magnus. Innervates all the muscles in the posterior compartment of the leg and sole of the foot.
Common fibular portion – Short head of biceps femoris, all muscles in the anterior and lateral compartments of the leg and extensor digitorum brevis.