Muscle · Glutes

Piriformis

Musculus piriformis

A flat, pear-shaped muscle that leaves the front of the sacrum, passes out of the pelvis through the greater sciatic notch, and ends on the top of the greater trochanter. It rotates the hip outward, and once the hip is flexed toward ninety degrees its line of pull changes and it abducts instead. Its clinical fame comes from its address rather than its action: the sciatic nerve leaves the pelvis alongside it, usually just beneath its lower border, so the state of this one muscle sits directly on the path of the largest nerve in the body. The founder's system calls that relationship 'sciatic protection', lists piriformis in the TIGHT column, and names piriformis tension as one of the three causes of sciatica — which makes it the muscle at the centre of the sciatica treatment flow.