What is Piriformis Syndrome?
Piriformis Syndrome is a fairly disabling neuromuscular condition. The piriformis muscle plays a key role in mobility – everything from walking to maintaining gait and balance to supporting the axial skeleton. On a ratio of 6:1, the majority of cases are reported in females.
Piriformis Syndrome accounts for almost 6% of all cases of sciatica.
The pyramid–shaped, obliquely-placed piriformis muscle serves as the external rotator of the hip when the hip joint is extended or flexed and is located in close proximity to the sciatic nerve.
Signs and symptoms of Piriformis Syndrome:
- pain felt in the region of buttocks or thigh;
- pain that is, at times, sharp and shooting as with sciatica and may involve the leg or calf and the foot;
- pain radiates into hamstring and calf muscles;
- a tingling sensation that may be associated with numbness;
- increase in the severity of pain after activities such as climbing stairs; prolonged hours of sitting; or an increase of pressure on the buttock;
- limitation in the range of hip motion;
- improvement in symptoms after rest.
How does it develop?
The piriformis muscle is a band-like muscle that attaches the femur or thigh bone to the hip bone. In 10% of the population the sciatic nerve actually passes through the piriformis muscle. In the other 90%, the nerve runs in close proximity to the muscle. Any trauma, over-use or long period of inactivity may cause the muscle to spasm and trap the nearby sciatic nerve beneath the muscle. Conditions that give rise to Piriformis Syndrome include but are not limited to:
- tissue injury or spastic conditions of the piriformis muscle normally seen in cases of tissue rupture or injury;
- inflammatory conditions of the piriformis muscle or of the neighboring joints or tissues (i.e. the sacro-iliac joint);
- high tension or stress in the adductor muscles of the hip joint that over-stretches piriformis muscle;
- hematoma formation in the region of piriformis muscle or in the vicinity that may press upon piriformis muscle.
Factors associated to an increased risk of developing Piriformis Syndrome include:
- professional sports, specifically running;
- occupations that involve long periods of driving, sitting on hard surfaces or extreme and strenuous physical activity;
- surgeries involving the hip joint (i.e. total hip arthroplasty);
- lumbar spinal issues and injuries that lead to fibrodysplasia.