Deep Fibular Nerve Flashcards Preview

► Med Misc 25 > Deep Fibular Nerve > Flashcards

Flashcards in Deep Fibular Nerve Deck (31):
1

What is the deep fibular nerve?

One of the terminal branches of the common fibular nerve

2

What are the nerve roots of the deep fibular nerve?

L4 and L5

3

What are the motor functions of the deep fibular nerve?

Innervates the muscles in the anterior compartment of the leg, as well as some of the intrinsic muscles of the foot

4

What are the sensory functions of the deep fibular nerve?

Supplies the triangular region of skin between the 1st and 2nd toes

5

How does the deep fibular nerve originate?

The sciatic nerve bifurcates into the common fibular and the tibial nerves at the apex of the popliteal fossa, at the back of the knee. The common fibular nerve wraps around the neck of the fibula, moving anterolaterally, and gives rise to the two terminal branches- superficial and deep fibular nerve

6

Where does the deep fibular nerve arise?

In the superolateral aspect of the leg, between the fibularis longus muscle and the neck of the fibula

7

What is the anatomical course of the deep fibular nerve?

The nerve moves from the lateral compartment to the anterior compartment of the leg. It then follows the course of the anterior tibial artery, in an inferomedial direction. Together, teh two structures pass between the tibialis anterior and the extensor digitorum longus in the superior portion of the leg, and between the tibialis anterior and the extensor hallucis longus in the inferior leg 
The deep fibular nerve crosses the ankle joint, passing anterior to the distal tibia, and travels deep to the extensor retinaculum

8

Where does the deep fibular nerve terminate?

In the dorsum of the foot

9

How does the deep fibular nerve terminate?

It divides into a lateral branch and a medial branch do

10

What does the lateral branch of the deep fibular nerve do?

Supplies motor innervation to some of the intrinsic muscles of the foot

11

What does the medial branch of the deep fibular nerve do?

Innervates the skin between the 1st and 2nd toes

12

Where are the muscles that the deep fibular nerve innervates found?

In the anterior compartment of the leg 
Some intrinsic muscles of foot

13

What muscles of the anterior leg does the deep fibular nerve innervate?

Tibialis anterior
Extensor halucis longus 
Extensor digitorum longus 
Fibularis tertius

14

What are the muscles of the anterior leg innervated by the deep fibular nerve responsible for?

Dorsiflexion of the foot

15

When is dorsiflexion of the foot required during the gait cycle for walking?

When a person strikes their heel on the floor in the stance phase
During the swing phase

16

Which intrinsic muscles of the foot are innervated by the deep fibular nerve?

The extensor digitorum brevis and extensor hallucis brevis

17

What are the intrinsic foot muscles innervated by the deep fibular nerve responsible for?

Extending the toes at the metatarsophalangeal joints and interphalangeal joints

18

Where does the deep fibular nerve terminate?

In the dorsum of the foot as the cutaneous nerve

19

What does the cutaneous nerve of the deep fibular nerve innervate?

The webbed space of skin between the great toe (hallux) and second toe

20

When can the deep fibular nerve become entrapped or compressed?

During its course through the anterior compartment of the leg

21

What does entrapment or compression of the deep fibular nerve cause?

Paralysis of the muscles in the anterior compartment of the leg, and so a patient loses the ability to dorsiflex the foot

22

What happens with unopposed plantarflexion?

The foot drops

23

What does footdrop give?

The patien’t foot difficulty in clearing the group during the swing phase of walking, and the limb looks too long
The foot will slap down on the floor when the patient walks, because it can’t be lowered in a controlled manner

24

How is footdrop compensated for when walking?

The patient develops an abnormal gait

25

What abnormal gaits may arise from footdrop?

Waddling gait
Swing-out gait 
High steppage gait

26

What happens in waddling gait?

The patient leans excessively onto the normal limb

27

What is swing-out gait?

The patient abducts the abnormal limb

28

What is high-steppage gait?

The patient flexes the hip and knee excessively on the abnormal limb, so as to clear the dropped foot from the floor

29

What are the main reasons that the deep fibular nerve could be compressed?

Anterior leg muscles may have been excessively used, and so are compressing the nerve within the anterior compartment 
Tight-fitting shoes may compress the nerve beneath the extensor retinaculum

30

What will the patient experience when the deep fibular nerve is compressed because of excessive anterior leg muscle usage?

Pain the anterior leg

31

What will the patient experience when the deep fibular nerve is compressed because tight fitting shoes?

Pain in the dorsum of the foot