The Sciatic nerve exits the spine right above the tail bone and travels down the back of the leg. The sciatic nerve is the main nerve for the entire leg, so if it is compromised or injured, you may loose the function of the leg. Sciatica is an early warning that the nerve is being compromised. Sciatica pain is often felt in the low back which would be the area where it exits the spine. Pain from a pinched sciatic nerve is often felt in the buttock and may radiate down the full length of the leg, all the way to the toes. The discomfort or pain from Sciatica can be a general painful ache, tingling and numbness at the back of the leg and may cause a weakness if the leg. Sciatic pain does have a few impersonators, which is why paying close attention to the symptoms and behavior of the pain is important.
Sciatic nerve pain can be caused both by structural and functional problems. The reason most often quoted by surgeons is that there is a narrowing in the channel where the nerve exits the spine. Dr. Janet Travell discovered a more frequent and easier to fix functional problem. The Sciatic nerve can become trapped by the Piriformis muscle which is one of the muscles serving to externally rotate the femur.
The mechanics of the Piriformis muscle is important. When hip flexion is less than 90 degrees (typical for walking and standing), the muscle serves to externally rotate the femur and the leg. If the leg is constantly being internally rotated by over-pronation, the Piriformis muscle will have to work harder. Harder working muscles become bigger, but they can also develop trigger points - taught bands within the muscles that cause cramping and pain.
The Sciatic nerve travels through the hip girdle through the same opening (greater sciatic foramen) as the Piriformis muscle, so you can immediately start seeing the problem. They both require space to function properly, and if the Piriformis muscle is in a state of over-use, it may put the squeeze on the Sciatic nerve. This is called Piriformis Syndrome, and is a frequent cause of Sciatica. Sometimes the muscle itself can squeeze the nerve, but this is less prevalent. In about 15% according to Dr. Travell, the Sciatic nerve is actually routed through the body of the Piriformis muscle, which increases the chance of sciatic pain.
The sciatic pain imposters differentiate themselves by the pain pattern. First, trigger points in the Piriformis muscle itself can create a similar pain pattern in the buttock and upper thigh. Trigger points in the glutes, your buttock muscles can give you a simplar pain pattern. These trigger points will often add a few painful areas such as pain in the tailbone and over the top posterior ridge of your hips that will help differentiate a true nerve entrapment. These trigger points will however not weaken the lag or radiate past the upper portion of the thigh. One of the ways to amplify the glute imposters is to carry your wallet in your back pocket and sitting on it.
How to eliminate the pain
Relatively few people diagnosed with Sciatica pain have disc problems. Many doctors will prescribe anti-inflammatory, pain reducing drugs for Sciatica, but while it may mask the pain, it will probably not get to the root cause and eliminate the problem. Bed rest may also help alleviate the problem, but it is seldom a permanent solution. At some point you need to get back on your feet again, and what happens then? Your body mechanics will be the same.
As simple as it may seem, a posture correction and correction of your gait mechanics may be sufficient to alleviate the pressure exerted on the Sciatic nerve. As mentioned above the Piriformis muscle is one of several muscles that externally rotates your femur. The problem with improper gait mechanics, especially over-pronation is a propensity of the feet to almost continually force an internal rotation of the leg. So it becomes a battle between the feet and the rest of the body. The knees often get in trouble, and the Piriformis muscle can get a work-out beyond that for which it was intended. Building up a muscle which penetrates a tight space is not a good thing, but stretching the muscle is very helpful The stretch would be lying down on your side opposite the painful buttock and leg. Allowing the upper leg to rotate inward so the knee crosses the midline of your body will give the Piriformis muscle a good stretch.
While the Piriformis muscle can also develop painful trigger points, Piriformis Syndrome is also often associated with the Glutes acting up from the same problem, over-pronating feet.