When suffering from leg symptoms caused by a pinched nerve, the trick is figuring out whether the site of the nerve compression is in the leg itself or in the lower back. The leg has only a few major nerves and a limited number of places where those nerves could be pinched. Physical examination is the most important tool in making an accurate diagnosis. A nerve test called an electromyogram (EMG) can provide additional information, if needed. Treatment depends on the site and underlying cause of the pinched nerve, and may include physical therapy, medication or surgery, in some cases.
In the Back
The lower back is the most common location for a pinched nerve leading to leg symptoms. Radiculopathy refers specifically to compression of a nerve root where it comes out of the spine. This condition typically causes tingling and/or pain partially or all the way down the leg. With severe compression, the muscles controlled by the affected nerve might also become weak. Treatment depends on the underlying condition leading to the pinched nerve, such as a herniated disc, arthritis or scar tissue. Physical therapy can often relieve the problem, but spinal injections are sometimes necessary for pain relief. Surgery may be needed to definitively solve the problem, particularly if the condition is progressive.
In the Buttock
Sciatica is a general term describing pain that radiates down the back of the leg, and piriformis syndrome is one of the more common possible causes. The syndrome most often occurs when the piriformis muscle in the middle of the buttock spasms and compresses the large sciatic nerve that runs under or through it -- although other factors might contribute to nerve compression at this site. With piriformis syndrome, aching buttock pain and sciatica typically worsen with prolonged sitting and walking up stairs. Physical therapy is the primary treatment for piriformis syndrome. The goal is to loosen the muscle and its grip on the sciatic nerve. Physical therapy also aims to correct the underlying issues that contributed to the development of piriformis syndrome. Very rarely, surgical release of the muscle is necessary.
At the Knee
The peroneal nerve, a major branch of the sciatic nerve, wraps around the outside of the knee just under the skin. Being so superficial, it is prone to compression -- most commonly by the other knee when your legs are crossed. This typically results in temporary tingling or numbness of the lower leg or foot, or even foot weakness. Symptoms are usually self-limited and no treatment is needed. However, if the nerve was pinched for a prolonged period or symptoms do not resolve quickly, there may be nerve damage. Again, physical therapy would be the main treatment to address nerve stimulation and strengthening as needed. If you're experiencing foot drop, an orthotic boot or plastic mold may be needed to support the foot.
At the Ankle
Tarsal tunnel syndrome refers to compression of the posterior tibial nerve within the tarsal tunnel on the inside of the ankle. Bones and the overlying connective tissue form this tunnel through which nerves and some tendons travel on their way to the foot. Tarsal tunnel syndrome is similar to the carpal tunnel syndrome at the wrist. Symptoms can include numbness, tingling, pain, and cramping on the bottom of the foot. Anti-inflammatory drugs can relieve inflammation in the tunnel that may contribute to the nerve compression. Physical therapy is used to further relieve the pressure in the tunnel and restore normal nerve function. Steroid injections can be of benefit in some cases. Surgery is sometimes necessary to open the tunnel and relieve the pressure on the nerve.
In the Foot
Morton neuroma is a knot of thickened tissue around an irritated nerve, usually on the undersurface of the foot between the third and fourth toes. Commonly resulting from tight shoes, neuromas develop due to constant pressure or irritation on the forefoot and cause numbness, stinging pain or tingling in the toes. A change of shoes, use of shoe inserts or orthotics, steroid injections, and physical therapy are all potential treatments. Surgery is possible but not usually necessary.
Other Considerations and Precautions
The ailments discussed are just some of the many medical conditions that can potentially lead to nerve compression with leg symptoms. An accurate diagnosis is the key to determining the best treatment options. Therefore, see your doctor as soon as possible if you experience leg symptoms that might indicate a pinched nerve. Seek immediate medical care if your symptoms started abruptly in association with a fall or accident, or if experience any warning signs or symptoms that might signal a serious underlying problem requiring urgent treatment. Possible warning signs and symptoms include:
-- new onset urinary or fecal incontinence
-- loss of sensation around the anus
-- sudden or rapidly progressive leg numbness or weakness
Reviewed and revised by: Tina M. St. John, M.D.