The Piriformis Syndrome: Kipper Feet

When World War 1 ended, doctors started to take a serious interest in patients with back problems. They were no longer content to believe that the rheumatic disorders stemmed from the circulation of an evil humour in the bloodstream, or form the absorption of poisons from the bowels. They felt there must be a mechanical explanation for many cases of lumbago an sciatica. An early product of this research was the identification of what came to be known as the Piriformis Syndrome. The first description of this entity, in a paper published in the Lancet in 1928, excited the medical profession …Here was a possible cause of sciatic pain which was easy to comprehend and simple to cure. But, despite its attractions, the Piriformis Syndrome had a life span as brief as that of a mayfly. Before it had time to establish its place in medical practice, it was usurped by a charismatic upstart – the Slipped Disc. From the moment in 1934 when doctors were informed that bulging spinal discs could cause pain by pressing on the emerging roots of the spinal nerves, it was accepted that this was the only important cause of severe back pain and sciatica. All rival theories were forced into obscurity. As a result most of today’s medical students receive their degrees without hearing a single word about the Piriformis Syndrome, yet this remains a frequent cause of back and leg pain.

The condition gets its name from the

piriformis muscle, a wedge shaped muscle which arises from the inside of the pelvic close to the sacro-iliac joint; this muscle becomes progressively tapered as it runs outward to finish as a tendon which is attached to the bump at the top of the hip bone. All anatomists agree that there is a very close relationship between the muscle and the sciatic nerve. In nine out of ten cases, the nerve runs under the belly of the muscle. In the remaining cases, the nerve takes one of three alternative routes. In just over seven per cent of individuals, part of the nerve passes through the piriformis muscle; in slightly more than two per cent, part of the nerve loops over the muscle belly and, in nearly one percent , the entire sciatic nerve travels through the substance of the piriformis muscle. In these anomalous situations in particular, it is possible for the become trapped or stretched by contraction of the piriformis muscle. This is the bass of the Piriformis Syndrome, which is characterised by pain in the buttock and leg which is often unrelated to movements of the spine, is usually not aggravated by coughing and sneezing, is relieved by rest and which is often most troublesome in the sitting position.

There are two reasons why the piriformis muscle is particularly prone to become bunched up and cause pressure on the sciatic nerve. In the first instance, the muscle derives some of its attachments from the ligaments spanning the sacro-iliac joint. Any strain of this joint can therefore cause reflex protective spasm of the piriformis muscles. The second reason for the peculiar vulnerability of the piriformis muscle is less easy to explain …(It occurs) whenever people walk with a flat-footed gait. This tends to rotate the whole leg inwards, As it is awkward and ungainly to walk with the knees pointing inwards, the body steps in at this point and makes an automatic adjustment. It rotates the entire leg outwards from the hip joint. … This is the best the body can do to correct the faulty gait, but the compensation has one serious mechanical drawback.

The piriformis muscle is an external rotator of the hip joint and will become shorter and fatter whenever the leg is held in a position of outward rotation. This increases the risk of sciatic nerve compression. If the leg is help permanently in this position, as happens whenever people walk with flat, kipper feet, the muscle undergoes adaptive shortening. This makes it less elastic and therefore more prone to strain…. There is one simple way to detect if the piriformis muscle on one side is shortened or in spasm. Lie relaxed on the flood for a few moments thinking about the weather, your mother in law, the state of your bank balance, or anything but the placing of your legs. Then glance down at the position of your legs. If one naturally, and habitually drops out further than the other, there is a probability that the piriformis muscle on that side is either shortened or contracted. … Strangely enough you are more likely to find piriformis shortening on the right-hand side of the body than on the left. This coincides with the finding that outward rotation of the leg is more than twice as common on the right-hand side than on the left. This may be due to an asymmetry of weight-bearing, for it is noted that five out of six children have a right foot which is broader than the left. ….An effective way of relieving spasm in the piriformis is to carry out the Yoga exercise known at ‘The Twist’, or to lie on the back, clasping the hands around the bent knee of the affected side, and slowly rotating it inwards. If the trouble has its origins in faulty body mechanics, as is so often the case, an attempt must be made to improve the gait and foot placement. Correct the tendency to walk with the legs turned outward like a penguin, and the feet to roll inwards. The latter can be done by wearing shoes with a strong inside counter and by strengthening the arch-supporting muscles. This can be done by slipping off the shoes and standing on one leg, an exercise which, for obvious reasons, I choose to call the stork. Piriformis shortening and spasm is a neglected cause of sciatic pain, which can be easily


( This item first appeared in Conquering Back Pain, second hand copies of which can still be bought online from Abe Books and Amazon for under £4 a copy, a price which includes postage and packing.)

Print This Post