What Causes Foot Drop?

What Causes Foot Drop?

Foot drop occurs when the muscles responsible for lifting the front of the foot and toes cannot work normally.

This may happen because of a problem affecting:

• A peripheral nerve in the leg
• A nerve root leaving the spine
• The spinal cord
• The brain
• The muscles themselves
• Communication between the nerves and muscles

The most common cause is injury or compression of the nerve that controls the muscles used to lift the foot. The NHS also recognises spinal-disc problems, diabetes-related peripheral neuropathy, surgery, prolonged immobility, neurological conditions and inherited muscle or nerve disorders as possible causes.

Foot drop is therefore a symptom rather than one single medical condition.

How Is The Foot Normally Lifted?

During walking, muscles at the front of the lower leg contract to lift the ankle and toes upwards.

This movement is known as dorsiflexion.

Dorsiflexion helps:

• Clear the toes from the ground
• Prevent the foot catching during the swing phase
• Position the heel for the next step
• Control how the forefoot lowers after heel contact

These muscles rely on nerve signals travelling from the brain and spinal cord through the leg.

A problem at any point along this pathway can reduce the ability to lift the foot.

What Is The Common Peroneal Nerve?

The common peroneal nerve—also called the common fibular nerve—passes behind and around the outside of the knee before dividing into branches that control movement and sensation in parts of the lower leg and foot.

It contributes to:

• Lifting the foot
• Lifting the toes
• Turning the foot outwards
• Sensation over the top of the foot and outer lower leg

The Royal National Orthopaedic Hospital describes the common peroneal nerve as supplying sensation to the top of the foot and controlling movements that lift the ankle and foot upwards and outwards.

Because the nerve travels close to the surface near the head of the fibula—the prominent bone on the outside of the knee—it can be vulnerable to injury or prolonged pressure.

Is Common Peroneal Nerve Injury The Most Common Cause?

Yes.

The NHS identifies injury to the nerve controlling the foot-lifting muscles as the most common cause of foot drop.

A common peroneal nerve problem may follow:

• Direct trauma around the knee
• A sports injury
• A fracture or dislocation
• Prolonged pressure against the outside of the knee
• Leg crossing
• Extended kneeling or squatting
• Prolonged immobility
• Surgery around the hip or knee
• Compression from swelling or scar tissue

Symptoms can include:

• Weakness lifting the foot
• Weakness lifting the toes
• Numbness over the top of the foot
• Tingling
• Burning or electric-shock sensations
• Weakness turning the foot outwards

The Royal National Orthopaedic Hospital notes that common peroneal nerve injury may produce pain, altered sensation and weakness lifting the foot and toes.

Can Crossing Your Legs Cause Foot Drop?

Prolonged leg crossing can place pressure on the common peroneal nerve where it passes around the outside of the knee.

The NHS lists crossing the legs, kneeling or squatting for long periods among recognised causes of nerve injury leading to foot drop.

The risk may be greater when:

• The position is maintained for a long time
• There is little soft-tissue padding around the knee
• The person has recently lost a significant amount of weight
• Sensation is reduced
• The nerve is already vulnerable
• The person remains immobile for extended periods

Occasional brief leg crossing does not mean foot drop will develop. The concern is sustained or repeated compression sufficient to disturb nerve function.

Can Kneeling Or Squatting Cause Foot Drop?

Long periods of kneeling or deep squatting can compress or stretch the common peroneal nerve.

This may be relevant in:

• Certain manual occupations
• Gardening
• Floor-level work
• Repeated crouching
• Prolonged religious or cultural postures
• Extended DIY tasks
• Sport or training positions

The NHS includes prolonged kneeling and squatting among possible causes of the nerve injury associated with foot drop.

New weakness or numbness following prolonged positioning should be assessed rather than simply assumed to settle.

Can A Sports Injury Cause Foot Drop?

Yes.

Sports injuries can damage or stretch the common peroneal nerve, particularly when there is trauma around the outer knee.

Possible mechanisms include:

• A direct blow
• Knee dislocation
• Ligament injury
• Fibular fracture
• Severe ankle or knee trauma
• Excessive nerve stretching
• Swelling that compresses the nerve

The NHS lists sports injury as one of the possible causes of common peroneal nerve damage leading to foot drop.

Foot drop after an acute injury requires prompt assessment because other structures may also be damaged.

Can Surgery Cause Foot Drop?

Foot drop may occasionally develop after surgery, particularly procedures involving the hip or knee.

Potential mechanisms include:

• Direct nerve injury
• Stretching of the nerve
• Pressure during positioning
• Postoperative swelling
• Scar tissue
• A collection of blood placing pressure on the nerve
• Prolonged immobility following surgery

The NHS includes hip and knee replacement surgery among recognised causes of nerve injury associated with foot drop.

New weakness after an operation should be reported promptly to the surgical or medical team.

Can Staying In Bed For A Long Time Cause Foot Drop?

Prolonged immobility can increase pressure around vulnerable nerves and contribute to weakness.

This may occur during:

• A long hospital admission
• Intensive care
• Recovery from severe illness
• Extended bed rest
• Reduced consciousness
• Restricted movement after surgery

The NHS identifies prolonged immobility, including a hospital stay, as a possible cause of foot drop.

Correct positioning, regular movement and pressure management are particularly important for people who cannot reposition themselves independently.

Can Weight Loss Contribute To Foot Drop?

Significant weight loss may reduce the natural cushioning around the common peroneal nerve at the outside of the knee.

This may make the nerve more vulnerable to pressure from:

• Leg crossing
• Firm furniture
• Bed positioning
• Braces or supports
• Prolonged crouching
• Tight straps

Weight loss alone does not necessarily cause foot drop, but it may increase susceptibility when combined with sustained compression or another nerve problem.

A healthcare professional should assess new weakness rather than attributing it solely to a change in weight.

Can A Slipped Disc Cause Foot Drop?

Yes.

A slipped or prolapsed spinal disc can press against a nerve root supplying the muscles that lift the foot.

Foot drop caused by a spinal nerve problem may occur alongside:

• Lower-back pain
• Pain travelling through the buttock and leg
• Pins and needles
• Numbness
• Weakness elsewhere in the leg
• Altered reflexes

The NHS lists a slipped disc as a recognised cause of foot drop.

The weakness may be caused by compression or irritation of nerve roots in the lower back rather than damage to the common peroneal nerve near the knee.

What Is Lumbar Radiculopathy?

Lumbar radiculopathy occurs when a nerve root leaving the lower spine becomes irritated or compressed.

It is sometimes called:

• A trapped nerve
• Nerve-root compression
• Sciatica
• Radicular pain

Depending on which nerve root is affected, symptoms may include:

• Back pain
• Leg pain
• Numbness
• Tingling
• Weakness lifting the foot or toes
• Weakness in other ankle movements

A brace may improve foot clearance, but it does not remove pressure from a spinal nerve.

The spinal cause must still be investigated and treated appropriately.

When Is Back Pain With Foot Drop Urgent?

Foot drop with new or worsening back and leg symptoms may require urgent assessment, particularly when weakness is rapidly progressing.

Seek emergency help if weakness occurs with:

• Numbness around the buttocks, genitals or inner thighs
• Difficulty starting urination
• Inability to pass urine
• Loss of bladder control
• Loss of bowel control
• Reduced awareness of bladder or bowel function
• Sexual dysfunction
• Weakness affecting both legs

These symptoms can occur when the bundle of nerves at the lower end of the spine is compressed—a condition known as cauda equina syndrome. NHS neurosurgical guidance describes leg, ankle or foot weakness alongside urinary, bowel and saddle-area sensory changes as possible symptoms.

This requires emergency medical investigation rather than waiting to see whether an AFO helps.

Can Diabetes Cause Foot Drop?

Yes.

Diabetes can damage peripheral nerves, a condition known as diabetic peripheral neuropathy.

The NHS lists diabetes-related peripheral neuropathy as a recognised cause of foot drop.

Diabetes-related nerve damage may cause:

• Numbness
• Tingling
• Burning pain
• Reduced sensation
• Muscle weakness
• Balance difficulties
• Greater risk of skin damage

Where sensation is reduced, brace selection and skin monitoring are particularly important because rubbing or pressure may not be felt normally.

What Is Peripheral Neuropathy?

Peripheral neuropathy is damage to nerves outside the brain and spinal cord.

Depending on which nerves are affected, it may cause:

• Weakness
• Numbness
• Tingling
• Burning
• Pain
• Reduced balance
• Loss of position awareness
• Foot drop

Peripheral neuropathy can have several causes, including diabetes.

Foot drop caused by a widespread neuropathy may affect both feet and may require more comprehensive support than a single lightweight lifting strap.

Can Stroke Cause Foot Drop?

Yes.

A stroke can damage the part of the brain responsible for controlling movement on one side of the body.

Foot drop after stroke may occur alongside:

• Weakness in the leg
• Weakness in the arm
• Facial weakness
• Reduced balance
• Altered sensation
• Muscle stiffness or spasticity
• Reduced coordination

The NHS lists stroke among the less common causes of foot drop resulting from damage to the brain or spinal cord.

Stroke-related foot drop may involve a more complex movement pattern than isolated peripheral-nerve weakness.

When Could Sudden Foot Drop Be A Stroke?

Call 999 where sudden foot or leg weakness occurs alongside:

• Facial drooping
• Arm weakness
• Speech difficulty
• Confusion
• Sudden one-sided numbness
• Visual disturbance
• Dizziness
• Sudden loss of balance
• A severe headache

The NHS advises using the FAST signs—face, arms, speech and time to call 999—and seeking immediate help even when symptoms improve after a short time.

Do not drive yourself to hospital or delay emergency care while trying a brace.

Can Multiple Sclerosis Cause Foot Drop?

Yes.

Multiple sclerosis can disrupt nerve signals travelling between the brain, spinal cord and muscles.

Foot drop associated with multiple sclerosis may vary according to:

• Fatigue
• Temperature
• Relapse activity
• Muscle stiffness
• Balance
• Sensory changes
• Walking distance

The NHS identifies multiple sclerosis as one of the neurological conditions that can cause foot drop.

Some people may benefit from an AFO, physiotherapy or functional electrical stimulation following specialist assessment.

Can Cerebral Palsy Cause Foot Drop?

Cerebral palsy can affect muscle control, coordination and tone.

A person may experience:

• Difficulty lifting the foot
• Spasticity
• The foot turning inwards
• Toe walking
• Reduced ankle movement
• Knee-control problems

The NHS lists cerebral palsy among conditions where damage to the brain may produce foot drop.

A simple elastic foot-lifting brace may not provide sufficient control where spasticity or fixed deformity is present.

Can Parkinson’s Disease Cause Foot Drop?

Parkinson’s disease can affect movement, walking speed, step length and the ability to initiate movement.

The NHS includes Parkinson’s disease among neurological conditions that may be associated with foot drop.

However, toe catching in Parkinson’s disease may also arise from:

• Shortened steps
• Reduced foot clearance
• Freezing
• Rigidity
• Balance impairment
• Generalised movement slowing

A full gait assessment is important before assuming that a dorsiflexion brace alone will solve the walking difficulty.

Can A Spinal Cord Injury Cause Foot Drop?

Yes.

Damage to the spinal cord can interfere with the nerve signals controlling the lower limbs.

The resulting movement pattern may include:

• Weakness
• Paralysis
• Spasticity
• Reduced sensation
• Balance problems
• Loss of selective muscle control
• Foot drop affecting one or both sides

The brace required depends on the neurological level, muscle tone, knee control and remaining sensation.

Can Charcot-Marie-Tooth Disease Cause Foot Drop?

Yes.

Charcot-Marie-Tooth disease is an inherited neurological condition that damages peripheral nerves.

It may cause:

• Progressive weakness in the lower legs
• Foot drop
• High arches
• Toe deformities
• Reduced sensation
• Balance difficulties
• Weakness affecting both sides

The NHS lists Charcot-Marie-Tooth disease among inherited causes of foot drop.

Because the condition can change foot shape and affect both legs, individual orthotic or footwear assessment may be required.

Can Muscle Disease Cause Foot Drop?

Yes.

Foot drop can occur when the muscles responsible for lifting the foot become weak because of a neuromuscular condition.

The NHS lists:

• Muscular dystrophy
• Spinal muscular atrophy
• Motor neurone disease

among the less common causes of foot drop.

The weakness may be progressive and may involve other muscle groups.

Brace selection should account for:

• Knee strength
• Hip strength
• Upper-limb function
• Fatigue
• Balance
• Ability to fit the device
• Expected progression

Can Foot Drop Be Caused By Motor Neurone Disease?

Motor neurone disease can cause progressive weakness, including weakness affecting the ankle and foot.

Foot drop may occur with:

• Muscle wasting
• Cramping
• Weakness elsewhere
• Reduced walking endurance
• Progressive mobility difficulty

The NHS identifies motor neurone disease as one of the muscle or nerve disorders that can produce foot drop.

Progressive weakness requires medical assessment and coordinated management rather than independent brace selection alone.

Can Foot Drop Affect Both Feet?

Yes.

Bilateral foot drop may be associated with:

• Peripheral neuropathy
• Inherited neurological conditions
• Muscle disease
• Spinal-cord problems
• Multiple nerve-root problems
• Generalised neurological illness
• Prolonged critical illness

Two-sided weakness may require assessment of:

• Hip and knee strength
• Balance
• Sensation
• Fatigue
• Upper-limb ability
• Walking-aid requirements
• Different support requirements on each side

The two feet should not automatically be treated with identical braces.

Does The Pattern Of Numbness Help Identify The Cause?

It may provide clues, but it cannot confirm the diagnosis by itself.

For example:

• Numbness over the top of the foot may accompany common peroneal nerve injury.
• Back and radiating leg pain may suggest a spinal nerve problem.
• Widespread numbness in both feet may suggest peripheral neuropathy.
• Weakness with facial, arm or speech symptoms may suggest a stroke.
• Saddle-area numbness with bladder changes may indicate cauda equina compression.

The Royal National Orthopaedic Hospital notes that common peroneal nerve injury may cause altered sensation over the top of the foot as well as foot-lifting weakness.

A clinician uses the complete history, examination and investigations rather than one sensory symptom alone.

Does Pain Help Identify The Cause?

Pain may offer useful information.

Possible patterns include:

Burning Or Electric-Shock Pain Near The Knee Or Foot

This may occur with peripheral-nerve injury.

Back Pain Travelling Down The Leg

This may suggest irritation or compression of a spinal nerve root.

No Pain

Some nerve injuries and neurological conditions cause weakness without significant pain.

Sudden Severe Back Pain With Neurological Changes

This may require urgent spinal assessment.

Common peroneal nerve injuries can produce burning, crushing or electric-shock sensations, but they can also present mainly as weakness or sensory loss.

Can Foot Drop Develop Without Pain?

Yes.

Foot drop can be painless.

A person may first notice:

• Scuffing the toe
• Tripping
• A slapping sound
• Difficulty walking on the heel
• Needing to lift the knee higher
• Uneven shoe wear
• Reduced control of the foot

Painless weakness still requires assessment because significant nerve or neurological problems do not always cause pain.

Is Sudden Foot Drop More Concerning Than Gradual Foot Drop?

Both require assessment, but sudden onset may be more urgent.

Sudden foot drop may occur after:

• Trauma
• Nerve compression
• Surgery
• A spinal-disc problem
• Stroke
• Acute neurological injury

Gradual foot drop may occur with:

• Progressive neuropathy
• Inherited neurological disease
• Muscle disease
• Longstanding spinal problems
• Progressive neurological conditions

The NHS advises seeing a GP whenever lifting the front of the foot or toes becomes difficult.

Rapidly worsening weakness should not wait for a routine brace purchase.

Can The Cause Be Temporary?

Yes.

Foot drop may improve where:

• Pressure on a nerve is relieved
• Swelling settles
• A mild nerve conduction block recovers
• The underlying injury heals
• Rehabilitation restores remaining muscle function
• A temporary postoperative problem resolves

The Royal National Orthopaedic Hospital explains that some common peroneal nerve injuries involve a temporary conduction block and may recover, while more severe degenerative injuries require the nerve to regrow and can take considerably longer.

The NHS states that foot drop may improve spontaneously or with treatment, although it can sometimes be permanent.

Can The Cause Be Permanent?

Yes.

Long-term foot drop may result from:

• Severe nerve injury
• Permanent neurological damage
• Progressive nerve or muscle disease
• Incomplete recovery following stroke
• Longstanding spinal-cord injury
• Irreversible muscle weakness

Where recovery is limited, treatment may focus on:

• Safer walking
• Foot clearance
• Preventing contracture
• Maintaining ankle position
• Improving stability
• Reducing falls
• Conserving energy

A long-term AFO may be required even when the original cause cannot be reversed.

How Is The Cause Diagnosed?

A clinician may ask about:

• When the weakness began
• Whether onset was sudden or gradual
• Recent surgery or injury
• Back or leg pain
• Numbness or tingling
• Diabetes
• Existing neurological conditions
• Recent weight loss
• Prolonged immobility
• Whether one or both feet are affected
• Falls or tripping

The examination may assess:

• Dorsiflexion strength
• Toe-lifting strength
• Other ankle movements
• Sensation
• Reflexes
• Muscle tone
• Knee and hip strength
• Walking pattern
• Balance

The NHS states that a GP may examine the leg and foot, observe walking and arrange referral for investigations such as imaging.

What Tests May Be Needed?

Tests depend on the suspected cause and may include:

• X-rays
• Ultrasound
• CT scanning
• MRI scanning
• Nerve-conduction studies
• Electromyography
• Blood tests
• Neurological assessment

The Royal National Orthopaedic Hospital notes that common peroneal nerve injury may be investigated using imaging and nerve-conduction studies.

Not every person requires every investigation.

Why Does The Cause Matter When Choosing A Brace?

Different causes produce different movement patterns.

A person with isolated flaccid weakness may mainly require assistance lifting the forefoot.

A person with spasticity may also require control of:

• Inward foot movement
• Ankle stiffness
• Toe curling
• Knee position
• Involuntary muscle activity

A person with peripheral neuropathy may need:

• Greater skin protection
• Pressure reduction
• Frequent monitoring
• More stable ankle control

A person with severe knee weakness may require an orthosis extending beyond the ankle.

The correct brace is determined by what needs controlling, not solely by the label “foot drop”.

What Is Flaccid Foot Drop?

Flaccid foot drop involves weakness with reduced muscle activity and little or no involuntary stiffness.

The foot may feel:

• Loose
• Weak
• Difficult to lift
• Uncontrolled during swing
• Prone to slapping down

This pattern may occur with some common peroneal nerve injuries or peripheral nerve problems.

The Boxia® Drop Foot AFO is specifically indicated for flaccid-paralysis foot drop.

What Is Spastic Foot Drop?

Spastic foot drop occurs where a brain or spinal-cord condition causes increased or involuntary muscle stiffness.

The foot may:

• Point downwards
• Turn inwards
• Resist correction
• Become stiff
• Develop toe curling
• Affect knee movement

A lightweight elastic support may not control significant spasticity, ankle instability or inward rotation.

A rigid, articulated or custom-made AFO may be required following professional assessment.

Can The Boxia® Treat The Cause Of Foot Drop?

No.

The Boxia® provides functional support by assisting forefoot lifting during walking.

It does not:

• Repair an injured nerve
• Remove spinal-nerve compression
• Reverse a stroke
• Cure peripheral neuropathy
• Restore permanently lost muscle
• Treat an underlying neurological disease

Its elastic tension strap helps lift the forefoot during the swing phase and may improve toe clearance for selected users with flaccid foot drop.

Who May Find The Boxia® Suitable?

The Boxia® may be considered where:

• Foot drop is flaccid
• The foot remains flexible
• The ankle retains adequate side-to-side stability
• Adjustable dorsiflexion assistance is required
• A lightweight external support is preferred
• A suitable secure shoe can be worn
• The user can monitor their skin and fit the device safely

Its features include:

• Adjustable elastic dorsiflexion assistance
• An ankle cuff
• External shoe attachment
• Breathable perforated material
• Gel-padded areas
• Multiple sizes
• Black and beige options
• Low bulk inside the shoe

The product contains latex.

Who May Need A Different AFO?

A more structured or custom-made AFO may be required where there is:

• Significant spasticity
• Severe ankle instability
• Strong inward turning of the foot
• A fixed deformity
• Major knee-control difficulty
• Significant sensory loss
• Fragile or damaged skin
• Bilateral complex weakness
• Insufficient control from elastic assistance
• A latex allergy
• Difficulty fitting or adjusting the product

Read:

How To Choose A Foot Drop Brace

Can Treating The Cause Improve Foot Drop?

Sometimes.

Treatment may involve:

• Relieving pressure on a nerve
• Managing a spinal-disc problem
• Treating diabetes or another neuropathy cause
• Rehabilitation after stroke
• Physiotherapy
• Electrical stimulation
• Nerve surgery
• Tendon transfer
• Ankle or foot surgery in selected cases

The NHS states that treatment depends on the cause and duration and may include physiotherapy, a brace or splint, electrical stimulation or surgery.

An AFO can provide functional support while recovery or investigation continues.

When Should You See A GP?

Arrange an assessment if:

• You cannot lift the front of the foot normally
• Your toes drag
• The foot slaps down
• You have started lifting the knee higher
• You are tripping more frequently
• Numbness or tingling has developed
• Weakness is worsening
• Foot drop follows injury or surgery
• Both feet are affected

The NHS specifically advises seeing a GP when it becomes difficult to lift the front of the foot and toes.

When Should You Call 999?

Call 999 where sudden weakness occurs with possible signs of stroke, including:

• Facial weakness
• Arm weakness
• Speech difficulty
• Confusion
• One-sided numbness
• Sudden visual disturbance
• Severe dizziness
• Sudden loss of balance
• A severe headache

Stroke symptoms may improve temporarily, but the NHS still advises immediate emergency help.

When Is Emergency Spinal Assessment Needed?

Seek urgent emergency assessment where foot drop or leg weakness occurs with:

• Severe or rapidly worsening back pain
• Weakness affecting both legs
• Numbness around the genitals or buttocks
• Difficulty starting urination
• Inability to pass urine
• Loss of bladder control
• Loss of bowel control
• Reduced awareness of bladder or bowel function
• New sexual dysfunction

These symptoms can indicate compression of the cauda equina nerves at the bottom of the spine. Early investigation is important because surgery can prevent further nerve damage but cannot always reverse damage that has already occurred.

The Key Takeaway

The most common cause of foot drop is injury or compression affecting the common peroneal nerve.

Other causes include:

• Sports injury
• Prolonged leg crossing, kneeling or squatting
• A slipped disc or compressed spinal nerve
• Diabetes-related peripheral neuropathy
• Hip or knee surgery
• Prolonged immobility
• Stroke
• Multiple sclerosis
• Cerebral palsy
• Parkinson’s disease
• Charcot-Marie-Tooth disease
• Muscular dystrophy
• Spinal muscular atrophy
• Motor neurone disease
• Brain or spinal-cord injury

The cause determines whether the weakness may recover and which treatment or brace is most appropriate.

A lightweight support such as the Boxia® may assist selected cases of flaccid foot drop, but it does not treat the underlying medical cause and will not provide enough control for every person.

New, sudden or worsening foot drop should be medically assessed—particularly where it is associated with stroke symptoms, severe back pain, bladder or bowel changes or rapidly progressive weakness.