Foot Drop: When You Cannot Lift Your Foot While Walking — Causes and Treatment

Foot drop is the inability to dorsiflex (lift) the foot at the ankle — the affected person cannot raise the toes or front of the foot while walking, causing the foot to drag along the ground. To clear the foot during walking, the patient compensates by lifting the knee higher than normal (steppage gait) or by swinging the leg outward (circumduction gait). Foot drop is a symptom — not a diagnosis — and can result from pathology at multiple levels of the nervous system.

Causes by Level

Common peroneal nerve palsy (most common peripheral cause): The common peroneal nerve wraps around the head of the fibula at the knee — extremely vulnerable to compression from habitually crossing the legs, prolonged squatting (agricultural workers, craftsmen), plaster cast pressure, or weight loss (loss of the protective fat pad). Causes foot drop + numbness over the lateral leg and dorsum of foot. Usually recoverable with nerve regeneration if the cause is removed.

Lumbar disc herniation (L4-L5): A large disc herniation at L4-L5 compresses the L5 nerve root — causing foot drop with pain radiating from the back down the lateral leg to the big toe. This is radiculopathy-caused foot drop — associated with back pain and a positive straight leg raise test. Spontaneous recovery in 85% with conservative management; surgical decompression if not improving after 6 weeks.

Stroke or brain tumour: A cortical or subcortical lesion affecting the motor cortex or corticospinal tract produces upper motor neuron foot drop — spastic, with brisk reflexes, a Babinski sign, and often accompanied by arm weakness and hemispatial neglect.

Peripheral neuropathy: Severe diabetic or hereditary neuropathy can cause bilateral foot drop with a symmetrical presentation.

Treatment

Ankle-foot orthosis (AFO) — a plastic brace that holds the foot in neutral position during walking — improves gait safety immediately while the nerve recovers. Physiotherapy: strengthening of ankle dorsiflexors; gait retraining. FES (functional electrical stimulation): a device that electrically stimulates the peroneal nerve during walking — an alternative to AFO. Surgical decompression if nerve compression from disc is the cause. Sri Anand CNC, Chanda Nagar, Hyderabad. Call +91 90633 66983.