Foot Drop: Causes, Symptoms, L5 Nerve Compression and Treatment

Foot drop is a weakness that makes it difficult to lift the front of your foot and toes towards your shin. It can cause your toes to drag along the ground, repeated tripping, or a noticeable change in walking. The most common causes include injury to the common peroneal nerve near the knee and compression of a nerve root in the lower spine, particularly L5.

Foot drop is not a disease itself. It is a sign that the muscles responsible for lifting the foot are not working normally.

Some people develop foot drop suddenly, while others notice gradually increasing weakness. It can occur with or without back pain, sciatica or numbness.

New foot drop needs prompt medical assessment, even when there is little pain. If it appears with stroke symptoms, new bladder or bowel dysfunction, or numbness around the groin, seek emergency medical care.

If your symptoms also include tingling or loss of sensation in the toes, read DRFK's guide to foot numbness by location and the nerves involved.

This guide explains the causes of foot drop, how doctors distinguish L5 nerve root compression from peroneal nerve injury, when MRI or EMG may be useful, and which treatments can support recovery.

Medical information associated with Op. Dr. Fatih Kırar, neurosurgeon and spine specialist at DRFK Dubai. Formal medical review is pending approval.

What Is Foot Drop?

Foot drop, also called drop foot or dropped foot, refers to reduced strength in the muscles that lift the front of the foot.

The movement is known as ankle dorsiflexion.

During normal walking, the toes must lift clear of the floor as the leg moves forwards.

When dorsiflexion becomes weak, the toes may drag along the ground. To compensate, a person may lift the knee unusually high.

This movement is known as a steppage gait.

Other people notice a slapping sound when the affected foot reaches the floor.

Foot drop may involve:

• One foot or both feet.
• Mild or severe weakness.
• Sudden or gradual symptom development.
• Weakness with or without numbness.
• Difficulty walking despite minimal pain.

The most important question is not simply whether the foot can move, but which nerve or neurological structure is responsible for the weakness.

What Are the First Signs and Symptoms of Foot Drop?

The earliest signs are often noticed during walking.

Common symptoms include:

• Difficulty lifting the front of the foot.
• Toes catching on the ground.
• Frequent tripping.
• Difficulty walking on the heel.
• Raising the knee higher than usual while walking.
• The foot slapping against the ground.
• Difficulty lifting the big toe.
• Reduced balance.
• Numbness or tingling over the top of the foot in some cases.

Some patients initially believe that their shoe is catching on the carpet or that they have simply become clumsy.

However, a repeated inability to clear the toes from the ground may indicate a loss of motor nerve function.

Is Foot Drop the Same as Foot Numbness?

No.

Foot drop is primarily a movement problem. Foot numbness is a sensory problem.

Foot drop affects the ability to lift the foot.

Numbness causes reduced or altered sensation, including tingling, pins and needles or loss of feeling.

Both may occur together when a nerve is affected, but one does not necessarily cause the other.

For example, pressure on the L5 nerve root may produce weakness and altered sensation in the foot, while other patients experience only sensory symptoms.

Learn more in our article on foot numbness, L5 and S1 nerve patterns.

What Causes Foot Drop?

Foot drop occurs when the muscles that lift the foot receive inadequate nerve signals or cannot function normally.

The cause may involve a peripheral nerve, a spinal nerve root, the brain, the spinal cord or the muscles.

Common Peroneal Nerve Compression

The common peroneal nerve, also called the common fibular nerve, is important for movement of the foot and toes.

It passes around the outside of the knee, near the head of the fibula.

Because it runs close to the surface in this area, it can be vulnerable to pressure and injury.

Possible causes include:

• Sitting with the legs crossed for long periods.
• Repeated squatting or kneeling.
• Direct injury near the outside of the knee.
• Tight casts or bandages.
• Prolonged immobilisation.
• Significant weight loss in some individuals.
• Certain surgical or traumatic injuries near the knee.

Compression may lead to weakness lifting the foot and turning it outwards.

Some patients also notice numbness over the top of the foot or the outside of the lower leg.

However, similar symptoms can occur when the source of the problem is in the lower spine.

L5 Nerve Root Compression

The L5 spinal nerve root contributes to the muscles that lift the foot and extend the big toe.

If this nerve root becomes compressed or irritated, muscle weakness may develop.

Potential causes include:

• Lumbar disc herniation.
• Lumbar foraminal stenosis.
• Degenerative changes in the spine.
• Narrowing around the spinal nerve root.

A disc herniation at L4-L5 can affect the traversing L5 nerve root, depending on its location.

Possible symptoms include:

• Difficulty lifting the foot.
• Weakness extending the big toe.
• Pain travelling from the buttock into the leg.
• Altered sensation over the top of the foot.
• Difficulty walking on the heel.

An important distinction is that L5 refers to the nerve root, while L4-L5 refers to a spinal disc level.

The two terms are related but are not interchangeable.

A disc abnormality shown on MRI also does not automatically prove that the disc is causing the weakness.

DRFK explains this distinction in its guide to nerve root compression on MRI and when it may require treatment.

Sciatic Nerve Injury

The sciatic nerve carries nerve fibres that contribute to movement and sensation in much of the lower limb.

Injury to this nerve may lead to weakness affecting the foot.

Potential causes include trauma, compression or injury affecting the hip and pelvic region.

A clinical examination, often supported by nerve testing, may be needed to distinguish this from an L5 nerve root problem.

Peripheral Neuropathy

Peripheral neuropathy refers to disorders affecting nerves outside the brain and spinal cord.

Conditions that may contribute include:

• Diabetes-related neuropathy.
• Hereditary neuropathies, including Charcot-Marie-Tooth disease.
• Inflammatory nerve disorders.
• Certain metabolic conditions.
• Some medication-related or toxic nerve injuries.

Not everyone with peripheral neuropathy develops foot drop.

When weakness occurs, the symptoms may affect several muscle groups or both feet.

Brain, Spinal Cord and Neuromuscular Disorders

Less commonly, foot drop may be caused by neurological conditions affecting the central nervous system or muscles.

Examples include:

• Stroke.
• Multiple sclerosis.
• Spinal cord disorders.
• Motor neurone disease.
• Certain muscular or neuromuscular conditions.

These conditions require different investigations and treatment pathways.

Sudden foot weakness accompanied by facial drooping, arm weakness or speech difficulty may indicate a stroke. Call emergency services immediately.

L5 Nerve Compression vs Peroneal Nerve Injury: How Are They Different?

Both L5 nerve root compression and peroneal nerve injury can cause foot drop.

However, the affected nerve is located in a different part of the body.

Signs That May Suggest L5 Nerve Root Compression

A clinician may suspect L5 radiculopathy when there is:

• Back or buttock pain radiating into the leg.
• Weakness lifting the foot and big toe.
• Weakness in other muscles receiving L5 nerve input.
• Sensory changes compatible with L5 involvement.
• Lumbar MRI findings consistent with the examination.

Signs That May Suggest Peroneal Nerve Injury

Peroneal neuropathy becomes more likely when there is:

• Previous pressure or injury around the outer knee.
• Weakness lifting the foot and turning it outwards.
• Sensory changes over parts of the outer lower leg and top of the foot.
• Nerve conduction abnormalities involving the peroneal nerve.

How Does the Neurological Examination Help?

One useful examination finding is the strength of ankle inversion, which turns the sole of the foot inwards.

This movement involves muscles supplied by the tibial nerve, with an important contribution from L5.

In an isolated peroneal nerve injury, inversion may remain relatively preserved.

With L5 nerve root dysfunction, inversion may also become weak.

However, these patterns are not absolute.

A patient may have more than one nerve affected, and weakness patterns can vary.

The diagnosis must be based on the complete examination, not one symptom or movement test.

Can a Herniated Disc Cause Foot Drop?

Yes.

A lumbar herniated disc can contribute to foot drop if it compresses a nerve root involved in lifting the foot.

L5 nerve root compression is one possible mechanism.

But there are three important points:

1. •Not every lumbar disc herniation causes foot drop.
2. •Not every case of foot drop originates in the lumbar spine.
3. •MRI findings must correspond with symptoms and muscle weakness.

For example, a patient may have an L4-L5 disc bulge on MRI while the actual cause of foot drop is compression of the common peroneal nerve near the knee.

Conversely, a person may develop foot weakness from an L5 nerve root problem despite having relatively little back pain.

If an MRI report mentions nerve narrowing, our article on foraminal stenosis and its neurological symptoms provides additional information.

Can Foot Drop Occur Without Back Pain?

Yes. Foot drop can occur without back pain, and the absence of pain does not mean the weakness is harmless.

Peripheral nerve compression around the knee can cause foot weakness without involving the lumbar spine.

Some cases of lumbar nerve root compression can also cause predominant weakness rather than severe back pain.

Therefore, the amount of pain is not a reliable measure of the severity of motor weakness.

A new inability to lift the foot requires prompt medical assessment.

Is Sudden Foot Drop an Emergency?

Sudden foot drop can indicate acute neurological dysfunction.

New foot drop should be assessed promptly, ideally on the same day, especially when the weakness is unexplained or worsening.

Immediate emergency assessment is necessary when it occurs with certain warning signs.

Stroke Warning Signs

Call emergency services immediately if sudden foot weakness is accompanied by:

• Facial drooping.
• Arm weakness.
• Speech difficulty.
• Sudden visual disturbance.
• Sudden loss of balance.
• Other sudden one-sided neurological symptoms.

Do not wait for symptoms to resolve.

Cauda Equina Syndrome Warning Signs

Cauda equina syndrome is a rare but serious condition affecting nerves in the lower spinal canal.

Warning signs include:

• New numbness around the groin, genitals or anus.
• New urinary retention or difficulty passing urine.
• New loss of bladder or bowel control.
• Rapidly worsening weakness in the legs.

These symptoms require immediate emergency assessment.

Rapidly Progressive Weakness

Seek emergency assessment if weakness rapidly worsens, becomes severe, affects both legs, or causes major new difficulty standing or walking.

A routine consultation booking should never delay emergency medical care.

How Is Foot Drop Diagnosed?

The purpose of diagnosis is to determine where the weakness originates and whether neurological function is stable or deteriorating.

1. Medical History

The doctor may ask:

• When did the weakness begin?
• Did it develop suddenly or gradually?
• Is one foot or are both feet affected?
• Is there back pain or radiating leg pain?
• Have you experienced knee injury or prolonged pressure around the knee?
• Have you been tripping or dragging the toes?
• Is there numbness?
• Are there changes in bladder or bowel function?
• Do you have diabetes or another neurological condition?

2. Neurological Examination

The examination may assess:

• Strength lifting the foot.
• Big-toe extension.
• Foot inversion and eversion.
• Leg and hip muscle strength.
• Tendon reflexes.
• Sensation in the feet and legs.
• Heel walking.
• Balance and walking pattern.

These findings help identify whether a nerve root, peripheral nerve or another neurological structure may be involved.

3. MRI Scan

A lumbar MRI may be appropriate when the examination suggests nerve root compression.

MRI may identify:

• Lumbar disc herniation.
• Foraminal stenosis.
• Spinal canal narrowing.
• Other abnormalities affecting nerve roots.

However, MRI is not automatically required for every person with foot drop.

Depending on the suspected cause, imaging of the knee, another part of the limb, the brain or spinal cord may be more appropriate.

For additional context, see Nerve Root Compression on MRI: Is It Serious and Does It Need Surgery?.

4. EMG and Nerve Conduction Studies

Electromyography (EMG) and nerve conduction studies (NCS) may help identify the location and type of nerve dysfunction.

These tests can help differentiate between:

• Common peroneal neuropathy.
• L5 radiculopathy.
• Sciatic nerve injury.
• More generalised peripheral neuropathy.

An early EMG can be inconclusive in certain recent nerve injuries because some electrical changes take time to develop.

The appropriate timing depends on the clinical question.

Urgent imaging or treatment should not be delayed solely to wait for an EMG test.

5. Additional Tests

Other investigations may be considered when peripheral neuropathy, metabolic disease, muscle disorders or central neurological conditions are suspected.

These may include blood tests or targeted imaging.

What Is the Best Treatment for Foot Drop?

There is no single treatment for every person with foot drop.

The most suitable treatment depends on:

• The cause of weakness.
• The location of nerve dysfunction.
• How long symptoms have been present.
• The severity of muscle weakness.
• Whether the condition is stable or deteriorating.
• The patient's overall health and mobility needs.

Treatment may include rehabilitation, orthotic support, management of the underlying disease or surgery in selected cases.

Can Foot Drop Improve Without Surgery?

Yes. Some cases improve without surgery, depending on the cause.

Non-surgical management may include physiotherapy, bracing and treatment of an underlying medical condition.

However, conservative treatment is not appropriate for every patient.

Significant or progressive weakness associated with nerve compression may require urgent specialist evaluation.

Physiotherapy for Foot Drop

Physiotherapy may support:

• Ankle mobility.
• Muscle strength where appropriate.
• Walking technique.
• Balance and coordination.
• Prevention of joint stiffness.
• Fall prevention.

Exercises should be selected according to the cause and degree of weakness.

Physiotherapy does not remove a serious structural compression that requires surgical treatment.

Ankle-Foot Orthosis (AFO)

An ankle-foot orthosis is a brace that helps support the foot in a safer position.

It may:

• Reduce toe dragging.
• Improve walking stability.
• Lower the risk of tripping.
• Support everyday mobility.

An AFO does not repair the damaged nerve, but it can improve safety and function during recovery or longer-term management.

Functional Electrical Stimulation

Functional electrical stimulation (FES) can activate appropriate muscles through timed electrical impulses.

It may help selected patients with foot drop arising from certain central neurological disorders, such as stroke or multiple sclerosis.

It is not suitable for every peripheral nerve injury.

For more information about different forms of nerve stimulation, read DRFK's peripheral nerve stimulation guide.

When Does Foot Drop Require Surgery?

Surgery may be considered when a structural problem is causing significant nerve dysfunction and treatment of that problem is likely to provide benefit.

Situations that may require a surgical opinion include:

• Lumbar disc herniation associated with clinically significant motor weakness.
• Progressive weakness caused by nerve root compression.
• Certain peripheral nerve entrapments.
• Traumatic nerve injuries.
• Persistent functional disability where reconstructive procedures may help.

For lumbar compression, surgery may involve decompression of the affected nerve root.

For selected peripheral nerve injuries, treatment may include decompression, repair or reconstruction.

In longstanding cases, tendon transfer may sometimes improve function.

Not every case of foot drop requires an operation.

The decision depends on the cause, neurological examination, investigations and likely benefits and risks of treatment.

How Long Does Foot Drop Take to Recover?

Foot drop recovery varies considerably.

Some patients improve over weeks or months, while others need a longer period of rehabilitation.

Some people experience persistent weakness.

Factors influencing recovery include:

• The type and severity of nerve injury.
• How long the weakness has been present.
• Whether the underlying cause can be treated.
• The extent of nerve damage.
• Other medical conditions.
• The response to appropriate treatment.

No reliable recovery timetable can be given from the symptom alone.

Follow-up assessment may be required to monitor strength and decide whether additional treatment is necessary.

Can Foot Drop Be Permanent?

Yes, but not always.

Severe or prolonged nerve injury may lead to lasting weakness.

However, certain causes of foot drop are reversible, and some patients regain substantial movement after appropriate treatment.

The prognosis depends on the underlying diagnosis rather than the term foot drop itself.

An MRI scan, examination and sometimes electrodiagnostic testing may help inform the prognosis, but none guarantees a particular outcome.

How Can You Prevent Falls With Foot Drop?

Foot drop increases the risk of tripping.

Practical safety measures include:

• Wearing supportive, properly fitted shoes.
• Removing loose rugs and cables.
• Keeping walking areas well lit.
• Using handrails on stairs.
• Asking whether a walking aid is appropriate.
• Discussing an AFO with a clinician.
• Avoiding activities that require reliable foot control until the weakness has been evaluated.

These measures support safety but do not treat the underlying cause.

Which Specialist Should Assess Foot Drop?

The appropriate specialist depends on the suspected diagnosis.

A neurologist may investigate unexplained weakness, peripheral nerve disorders and other neurological causes.

A neurosurgeon or spine specialist may assess patients when spinal nerve root compression is suspected.

Peripheral nerve specialists and rehabilitation teams may also be involved.

The aim is to establish where the nerve problem is located and how best to protect or restore function.

Foot Drop and L5 Nerve Assessment With Op. Dr. Fatih Kırar

Op. Dr. Fatih Kırar is a neurosurgeon specialising in brain, nerve and spine conditions at DRFK Turkish International Day Surgery Center in Dubai.

For patients with stable symptoms who have completed any necessary emergency assessment, a specialist consultation may help clarify the cause of weakness and the available treatment options.

Assessment may involve:

• Reviewing the onset and progression of weakness.
• Testing muscle strength and neurological function.
• Comparing symptoms with MRI findings.
• Considering whether peripheral nerve testing is needed.
• Evaluating possible lumbar nerve root compression.
• Discussing appropriate rehabilitation or treatment options.
• Planning further follow-up or referral where necessary.

The clinical objective is to determine whether the weakness originates in the lower spine, a peripheral nerve or another neurological structure.

European patients considering travel for specialist care should obtain urgent assessment locally first if the foot weakness is new, unexplained or progressing.

Book an Appointment With Dr. Fatih Kırar at DRFK Dubai

If your foot drop is stable and you need further neurological or spine evaluation, you can request a consultation at DRFK Dubai.

Book an Appointment at DRFK Dubai

You can select a relevant service such as Brain & Neurosurgery, Spine Treatment or Spine Surgery.

Patients who already have investigations should bring:

• MRI images and reports.
• Previous EMG or nerve conduction results.
• Relevant medical records.
• Current medications.
• Any previous specialist assessments.

Emergency reminder: Sudden foot drop accompanied by stroke symptoms, saddle numbness, bladder or bowel dysfunction, or rapidly progressive weakness requires emergency care rather than routine appointment booking.

Frequently Asked Questions About Foot Drop

What is the main cause of foot drop?

Common peroneal nerve injury or compression is a frequent cause. L5 nerve root compression and other neurological disorders can also produce foot drop.

Can L4-L5 disc herniation cause foot drop?

Yes. An L4-L5 disc herniation may affect the L5 nerve root, depending on the location of the disc abnormality.

Is sudden foot drop serious?

It can be. Sudden foot drop indicates new weakness that requires prompt medical evaluation. Additional neurological warning signs may make it an emergency.

Can foot drop happen without back pain?

Yes. It can arise from a peripheral nerve injury or from nerve root dysfunction with little or no back pain.

Is foot drop caused by nerve compression?

Sometimes. Common peroneal nerve compression and L5 nerve root compression are important causes, but there are other possible neurological and muscular conditions.

Can crossing your legs cause foot drop?

Prolonged pressure near the outer knee can compress the peroneal nerve. Certain leg-crossing positions may contribute to this in susceptible individuals.

Does foot drop always need surgery?

No. Some patients improve with non-surgical treatment, while others require a specialist surgical opinion.

Can physiotherapy cure foot drop?

Physiotherapy may improve walking and support recovery, but its effectiveness depends on the underlying cause. It does not resolve every form of nerve injury.

Can foot drop be cured completely?

Some people regain normal or near-normal function. Others experience incomplete recovery. The outcome depends on the cause and severity of nerve dysfunction.

How long does recovery from foot drop take?

Recovery may take weeks or months in some cases, longer in others, and may be incomplete. An individual prognosis requires medical assessment.

Can foot drop be caused by L5 nerve damage?

Yes. Dysfunction of the L5 nerve root may weaken muscles involved in lifting the foot and big toe.

What tests diagnose foot drop?

Diagnosis usually begins with neurological examination. MRI, EMG, nerve conduction studies or other tests may be used according to the suspected cause.

Is foot drop the same as sciatica?

No. Foot drop refers to impaired foot lifting, while sciatica generally describes symptoms associated with irritation of lumbar or sacral nerve roots. They may occur together.

When should I seek emergency treatment?

Seek emergency medical attention if foot weakness occurs with symptoms of stroke, new urinary retention, loss of bladder or bowel control, saddle numbness, or severe rapidly progressive weakness.

Conclusion: Why Early Diagnosis Matters

Foot drop is a loss of strength in the muscles responsible for lifting the front of the foot. It may result from common peroneal nerve injury, L5 nerve root compression, lumbar disc disease or another neurological condition.

The key to appropriate treatment is identifying the source of weakness.

Some cases improve with non-surgical treatment and rehabilitation. Others require specialist or surgical intervention.

New or worsening weakness should be assessed promptly, regardless of how much pain is present.

For patients needing further evaluation of a stable condition, book a consultation with Op. Dr. Fatih Kırar at DRFK Dubai to discuss appropriate investigations and treatment options.

Medical disclaimer: This article is provided for general educational purposes and does not replace an individual medical examination, diagnosis or treatment. Emergency neurological symptoms require immediate medical care.