Piriformis Syndrome

Reviewed on 3/18/2022

Facts You Should Know About Piriformis Syndrome

Picture of the piriformis muscle and sciatic nerve
Picture of the piriformis muscle and sciatic nerve
  • Piriformis syndrome is characterized by pain in the area of the buttock and hip area, although the discomfort can also extend down to the lower leg. It can cause symptoms very similar to sciatica.
  • Piriformis syndrome occurs when the piriformis muscle, which is located in the deep buttock area, compresses and irritates the sciatic nerve.
  • Risk factors for developing piriformis syndrome include being female, prolonged sitting, direct trauma, anatomical variation, and overuse seen with various athletic activities.
  • The symptoms of piriformis syndrome include pain and discomfort in the buttock area, sometimes radiating down into the lower leg. Some individuals may also experience numbness and tingling in the buttock and leg along the course of the sciatic nerve.
  • Piriformis syndrome is diagnosed by history and physical examination. Various imaging tests may be ordered to aid in excluding other causes of sciatica.
  • Treatment of piriformis syndrome may include a variety of interventions, including physical therapy, stretching, injections, nonsteroidal anti-inflammatory drugs, muscle relaxants, and as a last resort, surgery.
  • If properly diagnosed, piriformis syndrome is usually readily treatable, though some individuals may suffer from recurrence of symptoms or from chronic discomfort.
  • Piriformis syndrome sometimes can be prevented by modifying activity, stretching, and maintaining a proper rehabilitation program.

What Is Piriformis Syndrome?

Piriformis syndrome is a neuromuscular condition characterized by pain in the buttock and hip area from sciatic nerve compression or irritation. The discomfort may extend down to the lower leg, and it may be associated with numbness and tingling. It causes symptoms similar to sciatica, however the origin of the problem is not in the spine itself as with most cases of sciatica. Consequently, misdiagnosis or delayed diagnosis of piriformis syndrome is common.

This disorder was first described by Yeoman in 1928, and the term piriformis syndrome was subsequently coined by Robinson in 1947. The diagnosis of piriformis syndrome can be elusive. There is not a definitive uniform consensus on how to diagnose it, and there is not a single routine test that is diagnostic and specific for establishing the presence of piriformis syndrome. Therefore, the exact incidence and prevalence of piriformis syndrome is difficult to ascertain, with some authors estimating that 6% of cases of sciatica and low back pain are due to piriformis syndrome, while others claim that the actual percentage is much higher or much lower.

What Are Symptoms and Signs of Piriformis Syndrome?

Individuals with piriformis syndrome may experience a variety of symptoms, which may occur intermittently or they may be present chronically. The symptoms of piriformis syndrome are often made worse by prolonged sitting, prolonged standing, squatting, and climbing stairs.

  • Pain in the buttock or hip area is the most common symptom.
  • Pain may radiate from the buttock area down into the lower leg along the path of the sciatic nerve. Some patients may complain of low back pain.
  • There may be numbness and tingling in the buttock area, which can sometimes radiate down to the lower leg.
  • Pain with bowel movements may be present.
  • Women can sometimes experience painful intercourse.
  • There may be tenderness in the buttock area when pressure is applied. Certain patients may have a palpable "sausage shaped" mass in the buttock area from piriformis muscle contraction/spasm.

What Causes Piriformis Syndrome?

Piriformis syndrome is caused by compression of the sciatic nerve as it passes through the buttock. Typically, this occurs from spasm or contracture of the piriformis muscle. When the sciatic nerve is constricted and irritated, the individual will experience the symptoms of piriformis syndrome.

The piriformis muscle is a flat band-like muscle located deep in the buttock area. It functions to rotate the hip and turn the leg and foot outward. The sciatic nerve is a large nerve that exits from each side of the lower back and courses deep in the buttock region, down the back of the leg, and eventually branches off into smaller nerves ending in the foot. In most people, the sciatic nerve will course beneath the piriformis muscle in the deep buttock area. Normally, the sciatic nerve functions to connect the spinal cord to the muscles and sensory nerves of the legs.

What Are Piriformis Syndrome Risk Factors?

There are various risk factors that may make individuals more likely to develop piriformis syndrome.

  • Some studies suggest that piriformis syndrome is more common in females by a 6:1 ratio, thought to be due to anatomical differences.
  • Anatomical variation in the positioning of the sciatic nerve in relationship to the piriformis muscle may lead to piriformis syndrome. In some people, the sciatic nerve traverses through the piriformis muscle, for example, perhaps increasing the likelihood of sciatic nerve compression.
  • Direct trauma or injury to the buttock area can lead to swelling, hematoma formation, or scarring, which may lead to compression or entrapment of the sciatic nerve.
  • Prolonged sitting may lead to direct compression against the sciatic nerve. Piriformis syndrome has, therefore, sometimes been referred to as "fat wallet syndrome" or "wallet sciatica," as it has been found to occur in people continually sitting against their wallet on a hard surface.
  • Overuse or repetitive movements, such as occur with long-distance walking, running, cycling, or rowing can lead to inflammation, spasm, and hypertrophy (enlargement) of the piriformis muscle. This can increase the likelihood of sciatic nerve irritation or entrapment.

What Procedures and Tests Diagnose Piriformis Syndrome?

There is no single definitive test to diagnose piriformis syndrome. Piriformis syndrome is largely based on the individual's clinical symptoms and the findings on physical exam. Your health care professional may perform various maneuvers while examining you to see if the pain can be reproduced. These maneuvers can aid in diagnosing piriformis syndrome when your pain is exacerbated while stretching the piriformis muscle and thus irritating the sciatic nerve.

Imaging studies, such as MRI, are often ordered to exclude any other potential causes of sciatic nerve compression in the spine, such as disc herniation. Magnetic resonance neurography is an imaging technique that can be used to visualize sciatic nerve irritation and anatomic variations. Other imaging studies of the affected area, such as CT scanning and ultrasound, have limited diagnostic usefulness. Electrophysiologic nerve studies may also be undertaken in certain cases.

What Exercises, Pain Medicine, and Surgery Treat Piriformis Syndrome?

Piriformis syndrome can be treated using a variety of different approaches. There is no universal consensus on treatment for this condition, however, conservative treatment measures are usually attempted initially, with varying degrees of success.

  • Avoid strenuous activities that may exacerbate the pain, and avoid prolonged sitting, especially against a pressure area such as a wallet. Ice and rest may be helpful.
  • Individuals with piriformis syndrome may be taught various stretching and strengthening exercises that they can do at home.
  • For piriformis syndrome pain include
    • stretching and strengthening exercises,
    • massage,
    • myofascial release techniques, and
    • physical therapy.
  • Medications, such as NSAIDs (nonsteroidal anti-inflammatory drugs) or muscle relaxants, may provide pain relief for certain individuals.
  • Local injections of the piriformis muscle with corticosteroids, anesthetics, or botulinum toxin (Botox) may be treatment options for select patients.
  • Patients who have failed all conservative treatment measures may consider surgery as a last resort. This operation can take pressure off of the sciatic nerve by interrupting the piriformis muscle.

What Is the Prognosis for Piriformis Syndrome?

The prognosis for piriformis syndrome varies, often depending on when it is diagnosed. Since it is a condition that is often overlooked and misdiagnosed, delayed diagnosis is common. Generally speaking, individuals who are diagnosed earlier on in the course of the condition have a better prognosis and respond more favorably to conservative treatment. Those individuals who are not diagnosed in a timely manner may develop chronic piriformis syndrome, which can be more challenging to treat.

Tips to Prevent Piriformis Syndrome

Since piriformis syndrome is often caused by activities that cause repeated stress and microtrauma to the piriformis muscle, you can implement various measures to prevent this.

  • Properly warm up and stretch prior to engaging in strenuous physical activities.
  • Maintain proper form, balance, and posture when exercising.
  • Avoid those strenuous and physical activities that can potentially cause or exacerbate piriformis syndrome. If you experience pain or discomfort in the gluteal area during exercise, then cease the activity to prevent further injury.
  • Wear proper protective gear during work or sporting activities if direct trauma to the buttock area is possible.
  • Avoid periods of prolonged sitting on hard surfaces and avoid sitting on your wallet.

Piriformis Syndrome Cause

Symptoms of a Pinched Nerve

The symptoms of a pinched nerve depend on what nerve is affected. Each nerve is responsible for sending information to or from specific parts of the body.

The most common symptoms of a pinched nerve are:

  • pain,
  • numbness,
  • tingling (pins and needles), or
  • weakness of the muscles along the path of the nerve.
Reviewed on 3/18/2022
Boyajian-O'Neill, L.A., R.L. McClain, M.K. Coleman, and P.P. Thomas. "Diagnosis and Management of Piriformis Syndrome: An Osteopathic Approach." The Journal of the American Osteopathic Association 108.11 Nov. 2008: 657-664.