Hello everyone,its good to see you alla again and hope you all are doing well and i am too.we all know that we finished upperlimb and now we entered into lowerlimb in learning.and in previous post we learned about lumbosacral plexus and the major nerves which are originating from it.now we are going to see the major nerve common peroneal nerve its course and its muscle supply all the things.

COMMON PERONEAL NERVE/FIBULAR NERVE

We know that sciatic nerve is combination of tibial nerve and common peroneal nerve.so in the posterior region of thigh in the popliteal fossa sciatic nerve divided into tibial nerve and common peroneal nerve.you can see in the diagram.

Image source
The root value of it is posterior division of L4,L5,S1,S2

It is again divided into two nerves as Deep peroneal nerve and Superficial nerve

Image source

We learned that superficial nerve supplies lateral compartment of leg and deep peroneal nerve supplies anterior compartment of leg.so first we have to know what muscles are present in these compartments and their actions.

Anterior compartment of Leg

• Muscles -
  Peroneus tertius
  Tibialis anterior
  Extensor hallucis longus
  Extensor digitorum longus

• Action of muscles - Dorsiflexion/extension of foot

The below two images will make you understand the action of the anterior compartment muscles

No dorsiflexion/extension action of muscles

Dorsiflexion/Extension of foot

• Nerve supply - Deep peroneal nerve

• Sensory supply - 1st web space(skin in the cleft of 1st toe and 2nd toe

You can see below in my image that i made on my foot

Lateral compartment of leg

• Muscles -
  Peroneus longus
  Peroneus brevis

• Action of muscles - Eversion of foot

Eversion of foot

• Nerve supply - Superficial peroneal nerve

• Sensory supply - skin on the dorsum of the foot

CLINICAL CONDITIONS

we have understood the nervse supply to muscles and their actions and sensory supply.

Now we have to know what is going to happen if common peroneal nerve and its branches are injured.

• Deep peroneal nerve injured -

1)The anterior compartment muscles are paralysed so no dorsiflexion/extension of foot and it presents as FOOT DROP
2)Loss of sensation in 1st web space

Image source

• superfical peroneal nerve injured

1)If this nerve is injured then patient cannot perform eversion of foot as i shown in the image with my foot in one of the previous image.so EVERSION OF FOOT IS LOSS

2)Loss of sensation on dorsum of foot

This is all about common peroneal nerve its course and its supply to muscle and their action and sensory supply and clincal conditions.the next upcoming post is about tibial nerve.it is more to learn.stay tuned for that.

Thanks for reading,
With regards