The peroneal nerve is a human nerve that controls most of the sensation for the lower leg, including the toes and feet. Many animals have it, too. It is a branch of the sciatic nerve and it interacts in a number of important ways with many of the major muscle groups of the leg, including the peroneus longus and the peroneus brevis. No nerves truly control movement — their job is primarily the transmission of sensations to the brain — but the extent to which this nerve connects with and stimulates muscles gives it an unusually large role when it comes to things like toe curling and foot stretching. Problems with the nerve can cause a number of mobility issues as a result, and people usually need prompt medical care in case of injury to avoid permanent issues with movement and leg strength.
Where to Find It
The nerve typically runs the entire length of the leg, and is made up of three key segments or “branches.” It begins in the upper thigh at the top of the femur, and winds down the front of the leg; right around the so-called “funny bone” near the knee, it splits in two. A branch known as the “superficial fibular nerve” sits nearer the top of the surface of the leg muscles, typically on the front of the leg near the shin; the “deep fibular nerve” courses across the back, in most cases winding under the hamstring. The two meet again in the foot.
Main Function
The peroneal nerve serves many purposes. Like most nerves, its primary role is in delivering sensations from the nearby environment, here the leg, to the brain, and vice versa. The nerve is also somewhat unique in that it plays a role in movement, too. This is known scientifically as “innervation.” The nerve helps assist the major muscles of the leg such that a person can walk straight and have strength in the ankles and feet in addition to experiencing sensation in these same areas. Without this important nerve, people would have weakness in the ankles or feet, toes that drag when walking, and ongoing numbness or tingling at the top of the foot and in the lower leg.
Another benefit of the peroneal nerve is that it provides control over certain leg and toe muscles. If the nerve is destroyed or degeneration occurs, there is a loss of muscle control and muscle tone. Without the support from this nerve, most of the muscle mass in the lower leg could simply deteriorate.
Possibility of Damage
There are a number of ways this nerve can be damaged, but one of the most common causes is injury or trauma to the knee. The knee is where the nerve branches out, and injuries here can cause problems all up and down the leg as a consequence. The sheer volume of tendons and ligaments in the joint means that there are a number of different ways the nerve could be pinched or twisted, too.
A person doesn’t have to be in an accident or suffer a direct injury to the leg to risk damaging the nerve, though. In some cases regularly wearing high-heeled shoes, habitual leg crossing, and even pressure to the knee during deep sleep can cause problems with the nerve. Wearing tall boots that are tight along the calf can also cause damage if they put too much pressure on the skin. In addition, people who are extremely thin are at an increased risk of suffering damage to the nerve, usually for reasons of insulation and muscular strength. Proper nutrition is vital to maintaining the nerve's health, too.
Common Treatment Options
It’s usually pretty easy to correct nerve strain and pressure, but once there’s actually been an injury things can be much harder to solve. Injuries to this nerve tend to recover very poorly. In an attempt to repair damage to the peroneal nerve doctors may use surgical repair techniques that include nerve grafting, nerve suture, or decompression. In some cases a person may need a nerve transfer. This involves taking a branch from the lower leg muscle and connecting it to the muscle responsible for lifting the foot.