The Common Peroneal Nerve begins as the Sciatic nerve from the spine and winds its way to behind the knee. There it enters a tunnel on the outside of the knee, just below the head of the Fibula (“funny bone of the leg”). Here the nerve passes in an anatomic tunnel formed by the Peroneal muscles and Fascia. This nerve innervates the outside of the lower leg and also the top of the foot.
Compression of the Peroneal Nerve produces sensory symptoms like numbness or burning pain from the top of the foot to the knee. Muscular symptoms of this compression produce a drop foot with the leg and foot unable to walk on. Some experience Restless Leg syndrome while others describe unbearable pain in the leg or ankle.
Compression of this nerve is commonly seen in Diabetics or those with Neuropathy. Sports injuries like ankle sprains; broken ankles or knee sprains commonly seen in soccer, basketball, football, lacrosse, baseball, field hockey place patients at great risk for this injury.
Deep Peroneal Nerve Compression
Other branches of the Common Peroneal Nerve are exposed to compression on the top of the foot where a small tendon crosses over a smaller branch of the nerve and compresses it against the underlying bone. The injury produces strictly sensory pain like a knife sticking into the top of the foot. Pain may travel to the first and second toes. This compression occurs from too tightly tied laces, tight shoes, and direct trauma to the top of the foot producing a crush injury; a broken bone and arthritis.
Superficial Peroneal Nerve Compression
The least common area injury is in the lower outer leg where the Superficial Peroneal Nerve may be compressed. Symptoms are a burning to the area over the outer ankle and pain. Sprains and fractures usually produce this injury.