Quick Overview
The deep peroneal nerve is a mixed nerve that supplies both motor and sensory functions to the lower leg and foot. It is a branch of the common fibular nerve, which itself is a branch of the sciatic nerve.
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Read also Femoral Vein Anatomy and Axillary Vein Anatomy
Anatomy of Deep Peroneal Nerve
It begins at the apex of the popliteal fossa, where the sciatic nerve divides into the common fibular and tibial nerves. It then courses laterally and inferiorly around the neck of the fibula, enters the anterior compartment of the leg, and descends to the foot.
This nerve is primarily responsible for innervating the muscles in the anterior compartment of the leg, which are essential for dorsiflexion of the foot (lifting the toes towards the shin) and maintaining ankle stability.
Location
The DPN is located in the anterior compartment of the leg, deep to the extensor digitorum longus muscle. It passes between the tibialis anterior and the extensor hallucis longus muscles.
Function
The primary function of the deep peroneal nerve is to control the muscles involved in dorsiflexion of the foot. These muscles include the tibialis anterior, extensor hallucis longus, and extensor digitorum longus.
Dorsiflexion is crucial for walking, running, and maintaining balance during various activities. Additionally, the deep peroneal nerve provides sensory innervation to the skin on the dorsal aspect of the foot, including the first and second toes.
Branches
it gives rise to several branches which are;
1- Motor Branches: These branches innervate the muscles responsible for dorsiflexion and toe extension.
2- Sensory Branches: These branches provide sensory information from the skin on the dorsum of the foot.
Supply
This nerve supplies motor and sensory function to the following areas:
- Lower leg: anterior compartment
- Foot: dorsum and first web space
Clinical Importance
Injury to this nerve can cause foot drop, which is a condition in which the person is unable to dorsiflex their foot. This can make it difficult to walk and can lead to falls.
- Foot Drop: Damage to the deep peroneal nerve can result in a condition known as foot drop. Patients with foot drop have difficulty lifting their toes and may drag their foot while walking. This condition can be caused by trauma, compression, or nerve entrapment.
- Compartment Syndrome: In cases of acute or chronic compartment syndrome, increased pressure within the anterior compartment of the leg can compress the DPN, leading to pain, sensory changes, and muscle weakness.
- Nerve Entrapment: This nerve is susceptible to entrapment or compression at various sites along its course, such as the ankle or anterior knee. This can result in neuropathic pain and muscle dysfunction.
- Diabetic Neuropathy: Patients with diabetes are at risk of developing neuropathy, which can affect the this nerve. This can lead to sensory deficits and muscle weakness in the leg and foot.
Question
1. What is deep peroneal nerve entrapment?
Deep peroneal nerve entrapment refers to the compression or pinching of the deep peroneal nerve, usually within the anterior compartment of the leg. This can lead to symptoms such as pain, numbness, or weakness in the affected area.
2. What does the deep peroneal nerve innervate?
The deep peroneal nerve primarily innervates the muscles responsible for dorsiflexion of the foot, including the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles. It also provides sensory innervation to the skin on the dorsal aspect of the foot.
3. What are the symptoms of deep peroneal nerve injury?
Symptoms of deep peroneal nerve injury may include foot drop (difficulty lifting the toes), numbness on the top of the foot, weakness in dorsiflexion, and altered sensation in the affected area.
4. How is deep peroneal nerve distribution in the leg and foot?
The deep peroneal nerve courses through the anterior compartment of the leg, running alongside the anterior tibial artery. It divides into branches that supply the muscles and skin on the dorsal (top) aspect of the foot.
5. What are the roots of the deep peroneal nerve?
The deep peroneal nerve is a branch of the common peroneal nerve, which, in turn, originates from the sciatic nerve in the thigh. The nerve roots involved include the L4, L5, and S1 spinal nerves.
6. What causes deep peroneal nerve pain?
Deep peroneal nerve pain can be caused by various factors, including trauma, nerve entrapment, neuropathies (such as diabetic neuropathy), or excessive pressure within the anterior compartment of the leg (as in compartment syndrome).