Foot drop: causes, symptoms, treatment and recovery

Foot drop, also called drop foot, is where it is difficult to lift or move your foot and toes. The NHS says it usually affects 1 foot and can affect the way you walk.

It is a sign of an underlying problem in a nerve, the muscles or the brain or spinal cord rather than a condition on its own, so finding the cause matters.

The NHS says the most common cause is an injury to a nerve that runs down your leg and controls the muscles that lift your foot. It lists the following causes of that nerve injury.

• Sports injuries.

• A slipped disc in the spine.

• Crossing your legs, kneeling or squatting for long periods of time.

• Problems with your nerves (peripheral neuropathy) caused by diabetes.

• Hip or knee replacement surgery.

• Not moving for a long time, for example if you are staying in hospital.

The NHS says less common causes include inherited conditions such as Charcot-Marie-Tooth disease, muscle weakness caused by muscular dystrophy, spinal muscular atrophy or motor neurone disease, and damage to the brain or spinal cord caused by a stroke, cerebral palsy, Parkinson's disease or multiple sclerosis.

The Royal National Orthopaedic Hospital (RNOH) explains the common peroneal nerve (CPN) is in the lower leg behind the knee, and that nerves can be damaged by being stretched, squashed or cut, from a high-energy accident or from surgery, for example during a knee dislocation or after a total knee replacement.

The main symptom is difficulty lifting the front part of your foot and toes. RNOH lists the symptoms and signs of an injury to the common peroneal nerve as pain (commonly described as burning, crushing or like electric shocks), loss or change of feeling, with areas of numbness or reduced feeling, and foot drop, where you may have weakness in lifting your foot and toes up and out.

The NHS notes there is a higher risk of tripping and falling if you have foot drop.

The NHS says to see a GP if you find it difficult to lift the front part of your foot and toes. A GP will examine your leg and foot and look at the way you walk, and you may be referred to a specialist for more tests, such as an X-ray, ultrasound scan or CT scan, to find out what is causing it.

RNOH says you may be seen in clinic, where the doctor discusses how the injury happened and examines you, and further investigations such as an MRI scan, an X-ray or nerve conduction studies may be needed.

Foot drop that comes on suddenly with other symptoms, such as weakness elsewhere, facial droop, speech problems, or after a head injury, should be treated as urgent. Call 999 if you think you are having a stroke.

The NHS says treatment depends on what is causing it and how long you have had it, and that sometimes it can get better on its own. Common treatments include physiotherapy to strengthen or stretch the muscles in your leg and foot, a brace, splint or shoe insert to help hold the foot in position, and a small device put onto or under your skin that uses electrical signals to help your nerves work (electrical stimulation), especially if you have had a stroke or have multiple sclerosis.

If you have permanent loss of movement, you may have surgery to fuse the ankle and foot joints, or to repair or graft the nerve. RNOH describes nerve exploration, in which scar tissue around the common peroneal nerve may be released (neurolysis) and, if damage is more serious, nerve grafts may be needed. It says some injuries can be treated without surgery and may recover with time, and that currently no medicines are available that can improve these injuries, though analgesia may help if pain is a feature.

It varies. The NHS says foot drop can get better on its own and with treatment, but sometimes it can be permanent. RNOH explains that if the nerve has been squashed but not died back (a conduction block) it often resolves without surgery, like a hose-pipe that has been stepped on and takes time to open. If part of the nerve has died (a degenerative injury), it has to regrow, at about 1 mm a day.

RNOH says recovery time for the nerve injury itself is hugely variable, improvements are sometimes not seen for many months, and it may take up to two years to see the final function of the foot after surgery.

The NHS suggests simple changes to reduce the risk of tripping and falling.

• Wear shoes that fit well and support your feet.

• Use a walking aid, such as a stick, if you need one.

• Keep the floors in your home clear and remove things you could trip on, such as loose rugs and electrical cables.

• Keep your house well lit.

• Install handrails on stairs and put glow-in-the-dark (fluorescent) tape on the top and bottom step.

The Right Decisions Orthotics Evidence Portal, reviewed by the British Association of Prosthetists and Orthotists, covers drop foot arising from musculoskeletal causes such as peroneal nerve injury, lumbar nerve root entrapment or post-operative nerve damage. For neurological conditions such as cerebral palsy or stroke, it points to a separate neurology pathway. The NHS lists a brace, splint or shoe insert among common treatments.

If you are offered a brace or insert, ask who will fit and review it, and tell your clinician if it causes sore areas or changes how you walk.

On the NHS, a GP assesses foot drop and arranges imaging or nerve tests, with referral to physiotherapy, orthotics, neurology or orthopaedic and nerve-injury teams as needed. Some people choose private physiotherapy, orthotics or specialist assessment. In either setting the first step is working out whether the cause is in the nerve, spine or brain, because treatment differs.