‘Drop Foot’ and ‘Foot Drop’ are interchangeable terms that describe an abnormal neuromuscular (nerve and muscle) disorder that affects the patient’s ability to raise their foot at the ankle. Drop foot is further characterized by an inability to point the toes toward the body or upwards (dorsiflexion) or move the foot at the ankle inward or outward. Pain, weakness, and numbness may accompany loss of function. 1
A couple of common causes:
- The peroneal nerve (a division of the sciatic nerve) runs along the outside of the lower leg (below the knee) and branches off into each ankle, foot, and first two toes. It innervates or transmits signals to muscle groups responsible for ankle, foot, and toe movement and sensation.1
- Compression from lumbar disc herniation (ex. L4, L5, S1), or from a lesion of the forth or fifth lumbar root.1
Similiarly, patients with certain spinal tumors (that cause compression of the lower bundle of nerves in the spinal cord) may have a combination of symptoms. As the tumor grows:2
- Numbness or loss of sensation to the afflected toes and the dorsal surface of the foot.
- Weakness or loss of muscle tone of the legs (atrophy of the lower-lateral leg muscles). Muscular twitching of contiguous groups of muscle fibers might also then be observed in the atrophied muscles.
- Walking abnormalities (poor gait).
- Toes drag while walking.
• The Brace Shop – Foot Braces
2 Foot Drop : Article by James W Pritchett, MD, FACS – eMedicine
- MedlinePlus Medical Encyclopedia: Common peroneal nerve dysfunction
- Peroneal Mononeuropathy : Article by Pinky Agarwal, MD – eMedicine
- Foot Drop, Injury – Before and Afters – Texas Nerve & Paralysis Institute
- Foot Drop, Injury – Interactice Diagram – Texas Nerve & Paralysis Institute
- Nerve Transfers › Foot Drop – Washington University, Center for Nerve Injury & Paralysis