The piriformis muscle is a small muscle deep in the buttock area. It attaches at one end to the sacrum or the tailbone, and at the other to the femur - the long thigh bone.
Despite being small the muscle has an important role. Its main action (job) is to turn the hip joint outward, but it only does this when the hip joint is in a neutral position (which means not bent up). If the hip joint is bent up then piriformis also moves the leg outwards or away from your midline. The technical term for this is abduction.
You would be using it:
The muscle is also very important for stabilising the hip joint and the pelvis so it is also in action:
You can feel the muscle by feeling along the edge of the sacrum or the tailbone where it is attached. It's worth noting though that this muscle is deep in there and has close relationships with other pelvic muscles - look at the diagram above to see what I mean. Tis means it is very hard to feel it unless you know exactly what you are looking for.
An important point to make about this muscle is that the sciatic nerve either runs through it (in 30% of us) or very close by in the rest of us. This can sometimes lead to misdiagnosis of sciatic nerve problems caused by lumbar disc herniations.
Its a bit difficult to diagnose this problem yourself so you would probably need to be examined by a health care professional to make sure that you have the right diagnosis and can get the correct treatment..
Treatment for this syndrome involves accurate diagnosis of the cause of the problem. You need to find out if the muscle is short and tight or simply overactive because of core stability and hip muscle weakness. If the problem is one of shortness then I have a nice stretch video you can see. If the problem is more hip and core muscle patterning problems you need to look for a strengthening programme for the abdomen and pelvis. Your physio can help with that.