Piriformis syndrome is uncommonly diagnosed but is capable of producing sciatica like symptoms and back pain without there being any abnormality of the back itself. The syndrome refers to the capacity of the piriformis muscle of the pelvis to press on one of the largest nerves in the body, the sciatic nerve.
Piriformis syndrome can be caused by the muscle spasming or enlarging and it may be more common in more active people. It is also more common in women than men.
The symptoms of piriformis syndrome include simple lower back pain but it can cause shooting pains down the leg, mimicking sciatica caused by pressure on a nerve in the back itself.
The diagnosis can only be made reliably by a trained specialist. Tests such as a magnetic resonance imaging (MRI) scan may be used but primarily to exclude damage to the back itself as this scan, and other tests, are poor at identifying whether the piriformis muscle is truly pressing on or irritating the sciatic nerve.
If you think you have piriformis syndrome, consult your doctor. Simple stretching, exercise and physiotherapy may be beneficial as for other types of lower back pain.