There are many reasons why you may experience knee or leg pain or have a loss of sensation in those areas.
One of the most common causes is damage to the common peroneal nerve.
This damage may be caused by a sports injury, due to a medical condition or it can also be caused by compression to the nerve.
Where is the Common Peroneal Nerve?
The common peroneal nerve is one part of the sciatic nerve and is located behind the knee.
Due to where it is located, this nerve sustains more injuries than most of the other nerves in the lower leg.
If the nerve is damaged, it can affect the ability to feel or move the lower part of the leg, the foot or toes.
Causes of Common Peroneal Nerve Damage
When a nerve is damaged, either its myelin sheath, which covers a branch of the nerve cell called the axon, can be damaged or the nerve cell itself can be destroyed.
This can cause several problems like affecting major motor functions and foot drop, because the peroneal nerve helps to stimulate the muscles that control the foot.
There are several reasons for common peroneal nerve pain caused by damage.
Since the nerve is located behind the knee, any trauma, such as a blow to the knee, or other injuries to it can compress or damage the nerve.
Damage to this nerve isn’t uncommon when playing football or participating in other sports.
The peroneal nerve is also located at the back of the fibula, at the top of it, and winds around it where it breaks off into two branches, the superficial and deep peroneal nerves.
Since it is wound around the fibula, a break or damage to this bone can also result in an injury to the common peroneal nerve.
Compression to the nerve can also result in damage and compression can be caused by doing something as simple as crossing your legs or wearing tall boots that come up to the back of the knee.
It can also be damaged when the leg is in awkward positions during sleep, surgery or a coma or it can be damaged by some type of constriction to the lower leg, such as having a cast on the leg if it has been broken.
Who is More Susceptible to Nerve Damage?
There are some people who are more susceptible to having common peroneal nerve pain or nerve damage.
People who are thin, especially when caused by issues such as anorexia, will experience more damage due to compression.
Diabetics may have neuropathy issues with the peroneal nerve or people with polyarteritis nodosa, which is a disease of the blood vessels, are more susceptible to having the peroneal nerve damaged.
People who have a disease called Charcot-Marie-Tooth may also have issues with their common peroneal nerve.
The disease is hereditary and all of the nerves in the body are affected with damage to the peroneal nerve often happening in the early stages of the disease.
Also, prolonged exposure to certain toxins can damage this nerve.
Symptoms of Common Peroneal Nerve Pain
There are several signs of problems with the common peroneal nerve, especially in regard to some loss of motor function.
Along with common peroneal nerve pain, you may also experience numbness or tingling in either the upper or the lower leg, in the foot or the toes.
The tingling or numbness may be more pronounced in the top of the foot.
Since the peroneal nerve helps to control the function of the foot, damage to this nerve can affect the ability to hold the foot in an up position.
In addition to foot drop, when you walk, your foot may make a slap against the ground or the toes may drag.
Damage to the common peroneal nerve can sometimes affect a person’s ability to walk unaided.
Testing for Common Peroneal Nerve Damage
When you consult with a doctor regarding the common peroneal nerve pain or numbness you’re having, there are certain tests they may do to help diagnose the problem.
A physical exam can help reveal problems such as problems with muscle control or atrophy of some of the muscles in your leg or foot.
It may also show you having difficulty being able to lift your foot or your toes.
Your doctor may also order some tests done that will help him or her make a diagnosis, such as nerve conduction tests, a MRI to look for nerve compression or Electromyography.
The EMG will help test the electrical activity in the muscles of your leg or foot. A nerve ultrasound may also be done to help make an accurate diagnosis.
Treating Common Peroneal Nerve Damage
Most of the treatments for common peroneal nerve pain due to damage are centered around helping the patient regain their mobility.
Any disease leading to nerve damage, such as diabetes, will need to be included in the treatment.
To help reduce any swelling or inflammation of the nerve, your doctor may administer corticosteroid shots.
If the nerve damage is because of issues like crossing your legs, you may be prescribed a pad to wear to discourage crossing your legs and to help prevent any further damage it can cause.
Surgery may be necessary if there is no sign of improvement with other treatments, if there is damage to the axon of the nerve or if there are mobility issues due to the common peroneal nerve being damaged.
The surgery may help relieve compression of the nerve or remove tumors that are present.
If you do have continued common peroneal nerve pain, your doctor may prescribe pain medications to reduce it.
In addition, you may need physical therapy and/or use some orthopedic devices to help reduce problems with damage to the nerve like braces, splints or orthopedic shoes.
These treatments can help you regain your independence by helping improve any problems you have with mobility due to nerve damage.