A lot of people experience low back pain and/or sciatic nerve pain on a regular basis, however most people do not know what the cause is for their excruciating pain. Low back pain and sciatic nerve pain is not always the same thing, though many people experience them at the same time. All they know is that they feel it in their low back, and some times a shooting pain down their leg, so to them that is the spot that needs the work.
For low back pain, a fair amount of the time the muscles that need the work are in hip area (glutes or butt muscles) and thigh muscles (hamstrings, quadriceps), and/or the hip flexor, extensor, and rotator muscles. These muscles are generally underneath the large gluteal muscles (gluteus maximus, gluteus minimus and gluteus medius), so they can be pretty deep in there. When these muscles get tight they pull on the sacrum and hip bones which in turn pulls on the low back which where the person feels the pain. You can take a look at this link to Wikipedia to see what muscles are used by the hip: http://en.wikipedia.org/wiki/Hip_muscles.
Another group of muscles that seem to cause a majority of the low back pain is the iliopsoas (which is the psoas and iliacus muscles grouped together). These are rather deep muscles and they insert on the less trochanter (upper-inner thigh/hip area), so a lot of massage therapist will not work in that area. Also, a lot of massage therapists have not been trained on how to properly work that area to help release those muscles and not cause other undesirable results. So they are not able to get these muscles to release, and until they are relaxed the pain or discomfort will not go away. The other hip muscles (anterior and posterior) can also play a part in low back pain.
These muscles are used by the hips every time you move and they are “work-horse” type muscles and they keep working even though they are often neglected and forgotten about. That is until they don’t, then they are usually very tight and sore, and can cause pain to radiate down the leg or up the back. Sometimes the low back pain is a combination of tight and agitated muscles, which can make the pain worse and it more difficult to relieve.
The reasons these muscles get tight or agitated and inflamed can vary from person to person; it can be from lifting something incorrectly, sitting for extended periods of time, lying in bed for extended periods, injury, the way a person walks, etc. When a muscles gets over used or not used for a length of time (is stuck in one position) and then is suddenly used (moved in another position), it can cause it to tighten or become agitated and inflamed.
For sciatic nerve pain, the general cause for that seems to be an inflamed or injured piriformis muscle (located in the hip) which in turn presses on the sciatic nerve causing a shooting pain down the leg. Getting the piriformis muscles to relax is key to relieving the pain and discomfort felt. At times, this muscle and other hip and thigh muscles will be agitated or inflamed.
So low back pain and sciatic nerve pain can either be exclusive of the other or they can both affect a person at the same time. And one can lead to the other if the tighten or inflamed muscles is not addressed and in turn starts to pull on other muscles causing them to become agitated and/or inflamed.