Your doctor or physiotherapist has likely blamed that sciatic pain in your leg on problems with your spine, but as Dr Mitchell Yass argues, your back is not the culprit.
Up to 40 percent of all people worldwide suffer from the debilitating symptoms of sciatica—that pain that runs from the gluteal region to beyond the knee, most often to the foot.1
Initially you try the simple things—you change how you sit, try standing more and take medication—but eventually you can't take the symptoms anymore and seek medical attention.
This is the end of the line for any semblance of logic in understanding how to resolve sciatica.
As with most back symptoms, your doctor will usually suggest performing a magnetic resonance imaging (MRI) scan of the lumbar spine. Invariably, structural variations are identified: a herniated disc, stenosis (a narrowing of the spine) or a pinched nerve. It doesn't matter where on the spine the structural variations are present; they become the cause of the sciatic symptoms. All treatments will be aimed at fixing that part of the spine.
Doctors might start with epidural nerve blocks, cortisone shots, a bout of chiropractic care or even physical therapy, but most likely an epidural steroid injection will be recommended. Increasingly, epidural shots are the treatment of choice for back pain of all kinds, with over 10 million spinal injections now given annually in the US.2 These shots will eliminate the pain for a short period, ranging from a week to several months, but do nothing to fix whatever is causing the problem.
As time progresses, the symptoms begin to intensify and daily life becomes difficult, your doctor is likely to say, "There is nothing else that can be done except surgery." You agree to a highly invasive procedure—spinal fusion—not because of your doctor's logical and well-evidenced presentation as to what is causing sciatica, but simply because you can't take the pain any longer.
Sadly, for the millions who do agree to spinal fusion, the symptoms usually only continue and often increase in intensity. At this point, your surgeon looks at you and says, "All I can do is prescribe pain medication." You are left with an unpalatable choice: take medication to which you have a very high probability of becoming addicted 3 or live the rest of your life with increasing sciatic pain.
But these don't have to be your only two choices if you understand the real cause of sciatica—a cause very few in the medical establishment understand or attempt to treat.
What is sciatica?
By definition, sciatica is the irritation of the sciatic nerve, which starts in the gluteal region and ends at the back of the knee. This irritation of the nerve must occur somewhere along its path. However, what most people don't appreciate is that the sciatic nerve does not attach to the spine per se. Therefore, no altered structure at the lumbar spine can affect the entire sciatic nerve.
What does attach to the spine are the roots of smaller spinal nerves. They exit the spinal cord at every level, and those from the lower lumbar spine and sacrum join in the gluteal region to form the sciatic nerve.
An alteration to the structure of the spine can only affect the individual spinal nerve roots, not the sciatic nerve as a whole. Within the sciatic nerve, which innervates the entire leg, the nerve fibers from each individual spinal nerve all travel to the same area of skin. If a spinal nerve root is impinged, it creates symptoms only in that area of skin, not elsewhere on the leg.
Think of it like five tributaries that run into a river. If you block one tributary, you limit the flow of water to the river in just one of five sections. That is clearly not the same as blocking the entire river. Nerves work in the same way. If you impinge one nerve root that forms part of a larger nerve, this is not the same as impinging the entire nerve, which affects a much bigger area of the body. If a person's pain reaches from the gluteal region to the foot, it doesn't follow that their symptoms are caused by impingement of a particular nerve root attached to the lumbar spine, which only innervates the underside of the foot.
Instead, the impingement of the sciatic nerve must be occurring farther down the path of the nerve, from the gluteal region to the back of the knee.
The areas of skin covering the sciatic nerve are actually innervated by the different spinal nerves that exit the spinal cord at every level of the spine. No single spinal nerve runs from the gluteal region down the back or side of the leg to the foot. In order to cover all the portions of the leg and foot affected by sciatic pain, you have to include multiple spinal nerves—two from the lumbar spine and two from the sacrum.
It's also important to note that the sacral spine, a major source of spinal nerves that join the sciatic nerve, is composed of five fused bones. There are no discs at the sacral spine. By now, it should be overwhelmingly clear that sciatic symptoms cannot be created by any structural variation at the spine.
Even if you've had an MRI scan showing structural variations like a compressed disc at the time you had sciatic symptoms, chances are that if an MRI was taken even a year before you first experienced the symptoms, the exact same structural variations would have been found. Structural variations such as these are slow and progressive, and they take years, even decades, to develop.
Naturally, if structural variations were the cause of symptoms like sciatica, then people who experience no symptoms of sciatica also shouldn't have structural variations. However, as one study shows, 90 percent of people over the age of 60 who experience no back pain still show signs of bulging or degenerative discs,4 and up to three-quarters of people with no back pain have herniated discs.5 Even post-mortem studies going back to the 1950s found that the majority of cadavers show evidence of posterior disc herniations.6
If sciatica is not coming from the spine, what is creating the symptoms? In the two decades that I have been treating pain, I've discovered that the cause of most pain is muscular in nature. As we live in an environment with gravity, force is being pushed down upon you every time you try to perform a task or activity. The muscles responsible for generating movement must create forces that are equivalent to gravity or they will strain and elicit pain, cause other muscles to compensate, which themselves will cause or refer pain, or even strain and impinge on a nerve, causing the nerve to elicit pain. This cascade will cause what we refer to as sciatica.
One such muscle that can impinge on the sciatic nerve is the piriformis, which runs from the sacral spine across the gluteal region to the hip joint. In up to 30 percent of the population, the sciatic nerve actually runs through the piriformis muscle.7
The theory that the piriformis muscle is the main culprit in sciatic pain was put forward in 2005 by Aaron Filler and colleagues at the neurosurgery division of Cedars-Sinai Hospital in Los Angeles. They developed a technique called magnetic resonance neurography, or MRN, as a more sensitive method of MRI to detect nerves.
The researchers did not feel that the results being obtained with conventional MRI were accurate, because MRI can only identify the spinal cord and nerve roots coming off of it—it's incapable of differentiating the contribution of each nerve root to the larger nerve it joins. Instead, they thought, a more sophisticated mechanism would help to determine what was causing the symptoms of sciatica. In studies using this high-powered MRN, they found that in 68 percent of cases of sciatica that did not respond to conventional treatment, the cause was the piriformis muscle impinging on the sciatic nerve.8
Sciatica and hip function
The cause of sciatica actually has nothing to do with the spine. All the muscles that exist in the gluteal region attach to and are involved in hip motion and function. When standing or performing any weight-bearing activity, a key muscle called the gluteus medius, which sits above the hip joint on the side of the pelvis, is responsible for stabilizing the pelvis and providing balance, especially in cases such as walking when one foot is off the floor.
If this muscle strains, the muscle next in position to try to compensate and assist is the piriformis. Since it is not in the best position to create the needed force, eventually it is likely to strain too. Once strained, it can thicken and impinge on the sciatic nerve, causing it to refer symptoms.
When trying to diagnose the cause of symptoms, it is better to look at the body as a whole to see if there are any other physical presentations that can help to confirm a diagnosis other than the location or intensity of the pain. One important clue is where your pain begins. If a person has sciatica, their pain usually begins in the gluteal region. All standard diagnostic guidelines clearly indicate that sciatica elicits pain at the buttocks and legs.
You can test this just by sitting on a toilet too long. Chances are that you will experience severe sciatica symptoms, but as soon as you stand up the symptoms will almost immediately dissipate. What happens is that the inside edge of the toilet seat presses into the back of your thigh with enough pressure to impinge the sciatic nerve as it passes from the gluteal region along the back of the thigh to the back of your knee.
Another good clue is a person's posture and movement patterns. If the cause of the sciatica is a strained gluteus medius muscle, we should be able to see other physical signs, such as one hip being higher than the other when standing, greater difficulty standing on one leg versus the other, or waddling when walking, especially on one side. The only way to understand which tissue is responsible for the symptoms is to look at the entire body and the symptoms present.
Now that it's clear sciatica has a muscular cause, leading to a neurological symptom associated with hip dysfunction, there are two steps to resolving it. The first is to shut the nerve impulse off by strengthening the quads, the gluteus medius and the anterior tibialis. Then, once pain no longer runs down the leg and is isolated to the gluteal region, focus on strengthening all the muscles that work together to provide support—the hamstrings, gluteus medius and gluteus maximus—so the piriformis never has a reason to strain and thicken again.
I have used this methodology for decades and can barely remember a patient who didn't achieve full resolution of their sciatic symptoms and regain full functional capacity.
Walking back into life
Joan, age 64, was leaving for a walking tour of Europe exactly one week from the time she came to me for the treatment of severe sciatic symptoms. Her symptoms were bad enough that she needed to stand and walk with a cane. She was diagnosed with a herniated disc in the lumbar region and extremely concerned that the symptoms she was experiencing would inhibit her from being able to perform the level of walking that was anticipated during this vacation. On a Monday she asked me if she should cancel the tour. The cost of canceling so late would be enormous, and I was confident that I could resolve her sciatic symptoms quickly because to my mind, the cause was simply a muscular deficit. I told her to wait till Wednesday or Thursday before canceling, while I established which of the hip muscles was strained, leading to the piriformis straining and impinging on the sciatic nerve.
I performed massage and stretching followed by the set of exercises I had designed to resolve the muscular cause. By the end of the week her symptoms had been fully resolved. She was able to stand and walk pain-free, and she had a wonderful time on her vacation with no limitation in her ability to perform weight-bearing activities.
Back to school
Susan, a 19-year-old college student, was suffering from such severe sciatic symptoms that it was almost impossible for her to sit in class for her lectures. She sought treatment during the summer before she was to return to college, making it very clear that if her pain wasn't resolved, she would not be able to return to school. After determining which hip muscle had strained, I performed some massage and stretching and offered her the series of exercises I'd designed. Within three weeks, her pain had fully resolved. She was able to sit for any extended period of time and was confident that she would be able to return to college without symptoms, and remain symptom-free so long as she continued with the exercises.