Peroneal nerve injury is a neurological condition that can significantly affect foot movement and walking. Many people are unaware that simple factors, such as sitting for prolonged periods in an improper position or continuous pressure on the knee, may contribute to this injury. Although the condition may initially present with mild numbness or slight weakness in the foot, it can progress to difficulty walking or a condition known as foot drop if not properly managed.The risk of developing a peroneal nerve injury is higher in certain individuals, particularly those with diabetes or those who have sustained injuries to the knee or lower leg. Therefore, it is important to recognize the symptoms early and understand the underlying causes, available treatment options, and methods of diagnosis. Treatment may include medications, physical therapy, or surgical intervention in severe cases.In this article by Dalili Medical, we will discuss the causes of peroneal nerve injury, its most common symptoms, diagnostic methods, and available treatment options. We will also explore whether the condition can indeed result from prolonged sitting or diabetes.

What Is a Peroneal Nerve Injury?

A peroneal nerve injury is a condition in which the peroneal nerve, located along the outer side of the knee and lower leg, becomes compressed or damaged. This can affect both foot movement and sensation. One of the most common signs of this injury is foot drop, a condition in which the affected person has difficulty lifting the foot or toes while walking. Peroneal nerve injuries are often caused by leg fractures, sports-related knee injuries, or direct pressure on the nerve due to prolonged sitting in improper positions.

Is a Peroneal Nerve Injury Serious?

Not all peroneal nerve injuries are serious. The severity depends on the underlying cause and the extent of nerve damage. In mild cases caused by temporary nerve compression, symptoms may gradually improve with rest and appropriate treatment. However, severe injuries or cases involving nerve laceration may require long-term treatment and, in some instances, surgical intervention to restore nerve and foot function.

Can a Peroneal Nerve Injury Be Caused by Sitting?

Yes, improper sitting positions are among the common causes of peroneal nerve injury, especially when:

• Sitting for long periods with one leg crossed over the other

• Applying continuous pressure to the outer side of the knee

• Remaining in positions that place direct pressure on the nerve for extended periods

Does the Peroneal Nerve Affect the Toes?

Yes, a peroneal nerve injury can affect the toes and may cause:

• Difficulty lifting the toes

• Numbness or loss of sensation in the toes

• Difficulty controlling toe movements while walking

Can a Peroneal Nerve Injury Cause Muscle Atrophy?

If the injury remains untreated for a prolonged period, weakness or atrophy of the muscles in the front part of the lower leg may occur due to impaired nerve signals supplying those muscles.

Can a Peroneal Nerve Injury Cause Frequent Falls?

Yes, the injury can increase the risk of tripping and falling because of difficulty lifting the foot and impaired balance during walking, particularly in severe cases of foot drop.

Does Diabetes Increase the Risk of Peroneal Nerve Injury?

Yes, diabetes is an important risk factor that can contribute to nerve damage, including damage to the peroneal nerve. Additionally, prolonged high blood sugar levels may slow the nerve’s recovery process compared with individuals who do not have diabetes.

Can Vitamin Deficiencies Affect the Peroneal Nerve?

Yes, deficiencies in certain vitamins, particularly B vitamins such as Vitamin B12, can contribute to nerve dysfunction and worsen symptoms such as numbness, pain, and muscle weakness.

Can Poor Sleeping Positions Affect the Peroneal Nerve?

Yes, sleeping for long periods while placing pressure on the outer side of the knee can increase compression of the peroneal nerve, potentially worsening symptoms or causing temporary numbness and weakness.

Can Rapid Weight Loss Affect the Peroneal Nerve?

Yes, rapid weight loss may reduce the protective fat padding around the knee, making the peroneal nerve more vulnerable to compression and injury.

Can Children Develop Peroneal Nerve Injuries?

Yes, children can develop peroneal nerve injuries, although they are less common than in adults. They typically occur as a result of:

• Direct injury to the leg or knee

• Continuous pressure on the leg

• Sports-related injuries or fractures

Symptoms in children may include foot weakness, foot drop, or difficulty walking.

Types of Peroneal Nerve Injury

First: Types of Peroneal Nerve Injury Based on Severity

1. Neuropraxia – The Mildest Form of Injury

In this type, the nerve is compressed or temporarily affected without being severed or permanently damaged. As a result, nerve signal transmission is disrupted for a short period.

Common causes include:

• Prolonged sitting in improper positions

• Direct pressure on the outer side of the knee

In most cases, symptoms improve gradually within a short period with rest and appropriate treatment.

2. Axonotmesis – Partial Nerve Damage

In this condition, the internal nerve fibers are damaged while the outer nerve sheath remains intact.

This type is characterized by:

• Noticeable weakness or difficulty moving the foot

• Numbness and sensory disturbances

• A longer recovery period

Recovery may take several months and often requires intensive physical therapy and a structured rehabilitation program.

3. Neurotmesis – Complete Nerve Transection

This is the most severe type of peroneal nerve injury, in which the nerve is completely severed or extensively damaged.

It often results in:

• Significant loss of foot movement

• Severe weakness or foot drop

• Loss of sensation in parts of the leg or foot

In most cases, surgical intervention is required, followed by a prolonged rehabilitation and recovery period.

Second: Types of Injury Based on the Location of Nerve Damage

1. Injury at the Fibular Head

This is the most common site of injury because the nerve lies very close to the skin surface, making it particularly vulnerable to compression and direct trauma.

2. Injury Around the Knee or Upper Leg

This type commonly occurs as a result of:

• Knee injuries

• Fractures

• Surgical procedures

Symptoms may be more severe depending on the extent of nerve involvement.

3. Injury to the Superficial or Deep Peroneal Nerve Branches

Superficial Peroneal Nerve Injury:
Primarily affects sensation in the foot and the outer aspect of the lower leg.

Deep Peroneal Nerve Injury:
Primarily affects foot movement and toe elevation, often causing significant difficulty while walking.

Causes of Peroneal Nerve Injury

1. Direct Nerve Compression

Because the peroneal nerve passes close to the skin surface around the knee, it is particularly susceptible to compression, especially in the following situations:

• Sitting for long periods with one leg crossed over the other

• Sleeping on one side for prolonged periods

• Improper use of tight casts, braces, or bandages

• Rapid weight loss, which reduces the protective fat cushion around the nerve

2. Trauma and Fractures

Significant injuries to the knee or lower leg can damage the peroneal nerve, including:

• Fibular fractures or other leg fractures

• Knee dislocation

• Sports injuries and accidents

3. Surgical Procedures

In some cases, surgical procedures may stretch or compress the nerve, including:

• Knee surgeries

• Total knee replacement surgery

• Ligament repair procedures

4. Chronic Medical Conditions

Certain medical conditions can weaken nerves and increase the risk of peroneal nerve injury, including:

• Diabetes mellitus, one of the most common risk factors

• Peripheral neuropathies

• Autoimmune disorders

5. Tumors or Compressing Masses

A cyst, tumor, or other mass located near the course of the nerve—even if benign—may compress the nerve and interfere with its normal function.

6. Poor Daily Habits

Certain daily habits may increase the risk of peroneal nerve injury, such as:

• Prolonged squatting

• Sitting positions that place pressure on the outer side of the knee

• Improper or excessive use of exercise equipment that places stress on the leg and knee

Symptoms of Peroneal Nerve Injury

1. Foot Weakness

Foot weakness is one of the most common symptoms and may include:

• Difficulty lifting the foot upward (dorsiflexion)

• Difficulty moving the foot outward (eversion)

• Foot drop, in which the foot drags during walking and becomes difficult to control

2. Difficulty Walking

The injury may significantly affect gait, causing:

• Dragging of the foot on the ground

• Excessive lifting of the knee to compensate for foot weakness

• Frequent tripping or balance problems

3. Numbness or Loss of Sensation

The injury may affect sensation in the leg and foot, leading to:

• Numbness along the outer side of the lower leg

• Numbness on the top of the foot

• Tingling or a “pins and needles” sensation

4. Pain

Although pain is not present in all cases, it may occur as:

• Mild to moderate pain along the side of the knee or lower leg

• Increased pain with movement or direct pressure on the nerve

5. Muscle Weakness

Nerve impairment may weaken certain muscles, particularly those in the front of the lower leg, resulting in:

• Weakness of the anterior leg muscles

• Difficulty lifting the toes

• Early fatigue while walking

6. Changes in Walking Pattern

An abnormal gait may develop as a result of foot weakness, including:

• High-stepping gait

• Increased reliance on the unaffected leg during movement

Diagnosis of Peroneal Nerve Injury

1. Medical History

The physician will ask about several important factors, including:

• When did the symptoms begin, and did they appear suddenly or gradually?

• Is there a history of knee or leg injury or fracture?

• Has there been prolonged sitting or pressure on the outer side of the knee?

• Has the patient undergone previous knee surgery?

• Does the patient have chronic conditions such as diabetes?

Second: Physical Examination

The physician will examine the foot and lower leg to assess nerve function. This typically includes:

• Testing the ability to lift the foot upward (dorsiflexion)

• Evaluating for the presence of foot drop

• Assessing the strength of the muscles at the front of the lower leg

• Testing sensation in:

  • The top (dorsum) of the foot

  • The outer aspect of the lower leg

• Observing the patient’s gait, as a high-stepping gait may develop to compensate for foot weakness

Third: Neurological Testing

1. Electromyography and Nerve Conduction Studies (EMG & NCS)

These are among the most important tests used to confirm a peroneal nerve injury. They help evaluate:

• The speed of nerve signal conduction

• The strength of nerve impulses

• The extent to which the affected muscles have been impacted

These studies also help determine:

• Whether the injury is caused by temporary nerve compression or actual nerve damage

• The severity of the injury

2. Imaging Studies

Magnetic Resonance Imaging (MRI)

MRI may be used to identify:

• Compression of the nerve

• Tumors or cysts near the nerve

• Knee or lower-leg injuries

X-rays

X-rays help detect:

• Fractures of the fibula or knee

• Bone abnormalities that may compress the nerve

3. Nerve Ultrasound

Ultrasound imaging may be used to visualize:

• The structure of the nerve itself

• Areas of compression or swelling surrounding the nerve

Complications of Peroneal Nerve Injury

1. Chronic Foot Drop

Chronic foot drop is one of the most common complications of peroneal nerve injury. It may result in:

• Persistent drooping of the foot during walking

• Permanent difficulty lifting the front part of the foot

• Progressive impairment of mobility and balance

2. Gait and Balance Disturbances

The injury may cause significant walking difficulties, including:

• Continuous dragging of the foot along the ground

• Frequent tripping and an increased risk of falls

• Greater reliance on the unaffected leg during movement

3. Muscle Weakness or Atrophy

If left untreated, the injury may lead to:

• Weakness of the muscles at the front of the lower leg

• Progressive muscle wasting (atrophy)

• A visibly thinner appearance of the affected leg

4. Loss or Reduction of Sensation

Chronic nerve injury may result in:

• Persistent numbness over the top of the foot or lower leg

• Reduced sensitivity to touch or temperature

• An increased risk of unnoticed injuries or wounds

5. Progressive Foot Deformities

Over time, some patients may develop structural changes in foot position, including:

• A permanently downward-pointing foot position

• Altered weight distribution during walking

• Increased stress on joints and muscles

6. Chronic Pain

Some patients may experience:

• Recurrent or persistent pain in the leg or knee

• Burning sensations or electric shock-like pain associated with nerve damage

7. Psychological and Lifestyle Impact

Peroneal nerve injury can affect a patient's daily life by causing:

• Difficulty participating in sports and routine activities

• Feelings of frustration or anxiety due to walking difficulties

• Dependence on assistance in severe cases

Medications for the Treatment of Peroneal Nerve Injury

The goals of medication therapy in peroneal nerve injury include:

• Relieving pain

• Supporting nerve function

• Reducing inflammation

• Promoting nerve recovery indirectly

It is important to note that medications alone are usually insufficient. In most cases, they are used alongside physical therapy and rehabilitation programs.

1. Pain Relievers and Anti-Inflammatory Medications

These medications may be prescribed when pain or inflammation is present around the nerve.

Paracetamol (Acetaminophen)

Paracetamol can help relieve mild to moderate pain.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Examples include:

• Ibuprofen

• Diclofenac

These medications help reduce pain and inflammation around the affected nerve.

⚠️ NSAIDs should be used with caution in individuals with stomach, kidney, or gastrointestinal disorders.

2. Medications for Neuropathic Pain

These are among the most commonly prescribed medications for nerve injuries because they specifically target nerve-related pain.

Common examples include:

• Gabapentin

• Pregabalin

These medications may help:

• Reduce numbness and tingling sensations

• Relieve burning or electric shock-like pain

• Calm excessive nerve signaling

3. Nerve-Supporting Vitamins

Certain vitamins may be used to support nerve health and promote recovery, including:

• Vitamin B1 (Thiamine)

• Vitamin B6 (Pyridoxine)

• Vitamin B12 (Cobalamin)

These vitamins may help:

• Improve nerve nutrition

• Support nerve regeneration

• Gradually reduce numbness and sensory symptoms

4. Corticosteroids in Selected Cases

In certain situations, a physician may prescribe corticosteroid medications such as:

• Prednisolone

These medications may be considered when:

• Severe inflammation is compressing the nerve

• Significant swelling develops following injury or surgery

⚠️ Corticosteroids are not routinely used for all patients and should only be administered under close medical supervision.

Additional Supportive Medications

Depending on the patient's condition, additional medications may be recommended, including:

• Muscle relaxants to reduce muscle tightness and spasms

• Medications that improve blood circulation, based on the physician's assessment and the patient's overall health status

Surgical Treatment of Peroneal Nerve Injury

1. Nerve Decompression

Concept

The goal of nerve decompression surgery is to relieve pressure on the peroneal nerve as it passes near the fibular head.

Procedure

• A small surgical incision is made on the side of the knee

• The tunnel through which the nerve passes is opened

• Any compressive structures, such as ligaments, scar tissue, or enlarged muscles, are removed

Indications

• Chronic nerve compression

• Nerve compression related to prolonged improper sitting

• Compression caused by tight casts or braces

• Early stages of nerve injury

Outcome

This procedure often produces favorable results when performed early.

2. Neurolysis (Nerve Release)

Concept

Neurolysis involves freeing the nerve from scar tissue or adhesions that interfere with its normal function.

Types

External Neurolysis
Removal of scar tissue surrounding the nerve.

Internal Neurolysis
Release of adhesions within the nerve itself. This technique is more delicate and less commonly performed.

Indications

• Cases resulting from previous inflammation

• Patients with scar tissue following surgery

3. Direct Nerve Repair

Concept

Direct nerve repair reconnects the two ends of a completely severed nerve.

Procedure

• Surgical exposure of the injured area

• Alignment of the severed nerve ends

• Precise microsurgical suturing using specialized surgical microscopes

Indications

• Sharp lacerations

• Acute traumatic nerve injuries

Note

Outcomes are generally better when surgery is performed soon after the injury and when the damaged segment is relatively short.

4. Nerve Grafting

Concept

A healthy nerve segment is used to bridge a damaged section of the peroneal nerve.

Procedure

• Removal of the damaged nerve segment

• Harvesting a donor nerve from another area of the body, such as the leg or forearm

• Using the donor nerve as a bridge between the two nerve ends

Indications

• Large nerve defects

• Severe or complex injuries

5. Nerve Transfer

Concept

A functioning nerve is redirected to restore muscle function affected by the damaged peroneal nerve.

Procedure

• Connecting a healthy nerve branch to the peroneal nerve or its target muscles

• Gradually retraining the brain to utilize the new neural pathway

Indications

• Severe or longstanding injuries

• Situations where the original nerve cannot be repaired

6. Tendon Transfer

Concept

A functioning tendon from a healthy muscle is transferred to restore foot movement when nerve recovery is unlikely.

Procedure

• Transferring a tendon from a healthy muscle in the leg

• Reattaching it to the foot to restore lifting function

Indications

• Chronic foot drop

• Irreparable nerve damage

7. Removal of the Compressing Cause

Concept

The procedure aims to eliminate any external structure compressing the nerve, such as:

• Cysts

• Benign tumors

• Hematomas (blood collections)

Procedure

• Surgical removal of the compressive lesion

• Immediate release of pressure on the nerve

8. Additional Orthopedic Procedures

In selected cases, additional orthopedic surgeries may be necessary, including:

• Correction of bone deformities compressing the nerve

• Stabilization of fractures affecting the nerve pathway

Tips for Managing Peroneal Nerve Injury

Reduce Pressure on the Nerve

Because the peroneal nerve is particularly vulnerable to compression around the outer aspect of the knee, patients are advised to:

• Avoid crossing their legs for prolonged periods

• Avoid sitting on the floor or in positions that place pressure on the knee

• Avoid excessively tight braces, wraps, or supports around the knee

• Change sitting positions regularly during prolonged periods of sitting

Protect the Foot While Walking

To improve balance and reduce the risk of falls:

• Wear comfortable, supportive footwear

• Choose shoes with non-slip soles whenever possible

• Use an ankle-foot orthosis (AFO) if foot drop is present

• Walk carefully and at a controlled pace

Adhere to Physical Therapy

Physical therapy is one of the most important components of recovery and may include:

• Strengthening exercises for the anterior lower-leg muscles

• Foot and toe lifting exercises

• Balance and gait-training exercises

• Electrical stimulation therapy (TENS) when recommended by a healthcare professional

Care for the Skin and Sensory Function

If numbness or reduced sensation is present:

• Inspect the feet daily for cuts, blisters, or injuries

• Avoid exposure to extremely hot or cold temperatures

• Use moisturizing creams to prevent skin cracking

Lifestyle Modifications

• Maintain a healthy body weight to reduce pressure on the nerves

• Avoid prolonged standing without movement

• Take regular breaks during work or extended walking activities

Sleep in Proper Positions

• Avoid sleeping directly on the affected side

• Avoid placing pressure on the knee while sleeping

• Consider using a small pillow to support the leg and improve positioning

Maintain Regular Medical Follow-Up

• Attend regular follow-up appointments with a neurologist or orthopedic specialist

• Undergo repeat EMG and nerve conduction studies when indicated

• Seek medical attention promptly if symptoms worsen or weakness increases

Psychological Support and Rehabilitation

Peroneal nerve injury can be frustrating at first, but many cases improve significantly with proper treatment.

• Consistent participation in physical therapy can greatly enhance recovery

• Patience is essential, as nerve healing often requires considerable time

• Maintaining a positive and realistic outlook can help patients stay engaged in their rehabilitation program