Foot Drop
Foot Drop
Foot drop, often manifest as the foot dragging during the swing phase of the gait, causing tripping and/or falls, may be due to upper or lower motor neurone lesions, which may be distinguished clinically.
- Stiff foot drop, with upper motor neurone lesions:
leads to a circumducting gait; it may be possible to see or hear the foot dragging or scuffing along the floor, and this may cause excessive wear on the point of the shoe. There will be other upper motor neurone signs (hemiParesis; Spasticity, clonus, hyperreflexia, Babinski’s sign).
- Floppy foot drop, with lower motor neurone lesions:
leads to a stepping gait (steppage) to try to lift the foot clear of the floor, and a slapping sound on planting the foot. At worst, there is a flail foot in which both the dorsiflexors and the plantar flexors of the foot are weak (e.g., in high sciatic nerve or sacral plexus lesions). Other lower motor neurone signs may be present (hypotonia, areflexia or hyporeflexia).
Causes of floppy foot drop include:
Common peroneal nerve palsy Sciatic neuropathy Lumbosacral plexopathy L4/L5 radiculopathy
Motor or sensorimotor polyneuropathy (e.g., hereditary motor and sensory neuropathy)
Motor neuronopathy (anterior horn cell disease) Mononeuropathy multiplex
These may be distinguished on clinical and/or neurophysiological grounds
References
McNamara B. Foot drop. Advances in Clinical Neuroscience &Rehabilitation 2003; 3(1): 24-25
Cross References
Cauda equina syndrome; Hemiparesis; Lower motor neurone (LMN) syndrome; Steppage, stepping gait; Upper motor neurone (UMN) syndrome
