Piriformis syndrome describes a pattern of pain in the lower back or buttock which may radiate down the leg as far as the foot. It is often accompanied by other disturbances such as pain in the groin, pins and needles or numbness in the leg, and sometimes bladder disturbances. We have been treating it successfully for the past 35 years with gentle osteopathic manipulation and acupuncture.
It can mimic other conditions such as 'slipped disc', sciatica, sacroiliitis or bursitis. it frequently goes unrecognised or is misdiagnosed and this often leads to extensive and inappropriate investigations with no conclusive findings. Just as often, because it is overlooked this hip and buttock pain is wrongly and ineffectually treated; yet when correctly diagnosed it is usually straightforward to treat using simple measures.
What is piriformis syndrome? To understand this you need to know a bit of basic anatomy.
The piriformis muscle (piriformis means 'pear shaped') lies in the big mass of muscles in your buttock which are usually called 'the glutes'.
It actually lies deeper than the gluteal muscles and it runs from the part of the pelvis called the sacrum to the outer side of the thigh bone - the femur. It is a very important muscle for posture and walking and running and its main action is to turn the thigh bone, and therefore the leg, outwards. If you lie on your back in bed and look down at your feet and see that one foot turns out more than the other this could well be due to a tight piriformis muscle.
Piriformis syndrome happens when the sciatic nerve which is the main nerve to the leg is irritated by pressure on it from a tight or tense piriformis muscle. Human anatomy can vary from one person to another. In most people the sciatic nerve passes out from the pelvis into the leg UNDER piriformis muscle. But in 6-22% of the population (estimates vary) the nerve passes THROUGH the body of the muscle, rather than under it. You can see that any spasm of the muscle will pinch or trap the sciatic nerve and put pressure on it. This pressure gives rise to the pain pattern of piriformis syndrome.
These spasms can be caused by an acute injury such as a fall onto the buttock, or from overuse in long distance running or walking, or repeated sitting on hard surfaces. In my experience one of the commonest causes is sitting on a long car journey.
The pattern of pain can vary but patients usually complain of some or all of the following symptoms;
Piriformis muscle may also be a major factor in restless legs syndrome, and releasing spasm in this muscle can make a substantial difference to RLS.
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