From the Research
Foot drop can result from either peroneal nerve damage or central/back issues, with distinct characteristics that help differentiate the cause, and the most recent study 1 suggests that iatrogenic nerve injury is a significant cause of foot drop, with 83% of patients showing improvement in ankle dorsiflexion after surgical intervention. The differences between foot drop caused by peroneal nerve damage and foot drop resulting from central or lumbar pathologies are crucial for diagnosis and treatment.
- In peroneal nerve foot drop, weakness is typically limited to the ankle dorsiflexors and evertors, causing difficulty lifting the foot while walking and resulting in a characteristic "steppage gait" where patients lift their knee higher to avoid dragging their toes.
- Sensory loss is usually confined to the dorsum of the foot and lateral lower leg, and reflexes remain normal except for a potentially diminished ankle jerk.
- Common causes include compression at the fibular head, trauma, or mononeuropathy. In contrast, central or back-related foot drop often presents with additional neurological signs beyond just ankle weakness, including:
- Involvement of other muscle groups in the leg
- Possible bilateral symptoms
- Hyperreflexia rather than normal reflexes
- Potential bladder or bowel dysfunction
- Back-related foot drop typically stems from L4-L5 radiculopathy or lumbar stenosis and may be accompanied by back pain radiating down the leg. The pattern of sensory loss is broader, following dermatomal distributions rather than peripheral nerve territories. Electromyography (EMG) and nerve conduction studies are valuable diagnostic tools to confirm the location of the lesion, with peroneal nerve issues showing conduction abnormalities specifically in that nerve, while central causes demonstrate broader neurological involvement, as noted in the study 1. The treatment approach should be based on the underlying cause, with surgical intervention being a viable option for iatrogenic nerve injury, as shown in the study 1, and conservative management being considered for cases of lumbar disk herniation, as suggested by the study 2.