Piriformis syndrome is a condition of sciatic nerve entrapment in Piriformis muscle at the greater sciatic notch which leads to pain in buttock region, numbness and tingling along the back of the leg (sciatic pain). Abnormal condition of the Piriformis muscle such as hypertrophy/spasm, inflammation, or anatomic variations (SIJ dysfunction) may lead to this condition.

Piriformis syndrome is often misdiagnosed cause of cause of low back pain as it may mimic with various other conditions such as lumbar canal stenosis, disc inflammation, or pelvis causes. Piriformis syndrome occurs most frequently during the fourth and fifth decades of life and affects individuals of all occupations and activity levels. It is more common in women than men.