- Piriformis Syndrome
Piriformis syndrome, the most common cause for sciatica nerve pain, occurs when the piriformis muscle places pressure on and irritates the sciatic nerve. This can cause a feeling of pain from your buttocks, and in extreme cases, down to your knees.
What Causes Piriformis Syndrome?
In most cases, imbalances in the core muscles pull the pelvic bones and hip joints out of place, which causes the piriformis muscle to contract and shorten, creating pressure on the nerve.
Other Common Causes of Piriformis Syndrome
In 15-30% of the population the sciatic nerve passes through the piriformis muscle, rather than underneath it. These people have been reported by some studies to have a greater incidence of piriformis syndrome than does the general population.
In addition to imbalanced muscles, sometimes piriformis pain is caused by overuse. Overuse injury is common when the legs are strenuously used while in the sitting position, i.e. rowing or bicycling.
Runners, bicyclists and other athletes involved in forward-moving activities are particularly susceptible to developing piriformis syndrome if they do not engage in the proper stretching and strengthening exercises. Repeated forward movements can lead to disproportionately imbalanced muscle groups.
Another purported cause for piriformis syndrome is stiffness, or hypomobility, of the sacroiliac (SI) joints where the pelvis meets your spine (aka tailbone). The resulting compensatory changes in flexibility would then result tearing the piriformis muscle, resulting not only in piriformis pain but in other low back pain syndromes as well.
Piriformis syndrome can also be caused by overpronation of the foot. When a foot overpronates it causes the knee to turn inward, causing the piriformis to activiate to prevent over-rotating the knee. This causes the piriformis to become overused and therefore tight, eventually leading to piriformis syndrome.
Piriformis syndrom may also be associated with falling injury.
Piriformis syndrome is also known as “wallet sciatica” or “fat wallet syndrome,” as the condition can be caused or aggravated by sitting with a large wallet in the affected side’s rear pocket.