Piriformis Syndrome (Sciatica)

Piriformis Syndrome is one of the causes of sciatica in which the inflammation occurs in the piriformis muscle as a result of a fall, injury, overwork, or extended periods of sitting or standing.

The sciatic nerve is one of the largest nerves in the body. If runs from the lower back and all the way into the feet. When the sciatic nerve is irritated or compressed, we may experience pain and other symptoms near the site where the sciatic nerve has been affected. These symptoms may also radiate down the leg. The sciatic nerve may be affected by irritation or compression of the nerves. Piriformis Syndrome is one of the causes of sciatica in which the piriformis muscle irritates the sciatic nerve.

Anatomy of the piriformis muscle: The piriformis originates in the anterior part of the sacrum, the greater sciatic notch, and the sacrotuberous ligament. The muscle exits the pelvis through the greater sciatic foramen and inserts onto the greater trochanter of the femur. The action of the piriformis muscle is lateral rotation of the hip.



The piriformis muscle lies just above the sciatic nerve in the buttocks region. This group of muscle is responsible for medial (turning in towards the body) and lateral (rotation of the leg away from the body) rotation of the hips and legs. This set of muscles the hips inward when sitting, and outwards when standing. Inflammation may occur in these muscles due to muscle strain, injury, overwork, and repetitive stress. Because of inflammation, the muscle may swell, pressing into the sciatic nerve, causing the symptoms of sciatica.

The symptoms of sciatica include lower back pain, pain in the buttocks, hips, legs and feet. The pain experienced may be a dull ache, or it may be sharp and radiating towards the feet. The compression of the nerve may also cause neurologic symptoms such as numbness, tingling, achiness, and weakness.

The people that are most often affected by piriformis syndrome are those whose occupation requires them to sit for extended periods, such as truck drivers, and people who work in office settings. People who have long work commutes may also be affected. People who need to stand for long periods of time may also be affected by this syndrome. Also, people who perform repeated tasks that stress the piriformis muscles may also be affected. Activities that may overstress the piriformis muscle include shoveling snow and playing golf, and too much aerobic exercise. Accidents or falls that strain this muscle, or slips that result in landing full force onto the muscle may also inflame it.

The primary symptom of piriformis syndrome is tenderness, and intermittent pain. The pain may come suddenly or gradually as a result of sitting or first getting up in the morning. The pain and discomfort may occur in the backside only, or it may also involve radiating pain down the leg, along the pathway of the sciatic nerve. Sitting may exacerbate the pain and radiating pain and other symptoms such as numbness and tingling in the buttocks.

Diagnosis: Patients who present with one or more of these symptoms will receive the following upon a physician visit:
  • A physical examination
  • Musculoskeletal examination
  • A history of the injury
  • The location of pain
  • Assessment of muscle strengths and weaknesses
  • Testing of reflexes