Sciatic Nerve Irritation

We may experience back pain, pain in our legs, or other changes in the senses of our hips, buttocks, and legs, when one or more sections of our sciatic nerve become compressed, or when there is sciatic nerve irritation along one of its branches.

The ability of our body to feel, sense, and provide us with motor functions is due to the nerve roots and nerve fibers that exit our spine and make their way into every tissue of the body. Those nerves give us our ability to move our body, sense the slightest changes in temperature, and of course to feel pain. Our nerves give us our ability to feel pain due to increases in pressure, such as when we are struck with a blunt object, and to feel an uncomfortable tension in our joints, such as when we are pulling our body beyond a healthy range of motion. These nerves may also cause us to feel chronic pain to certain regions to our body, such as when the nerves that exit our spine become damaged or compressed at some point. Here we will discuss nerve root compression, and sciatic nerve irritation.



Each nerve root has four main branches that divide almost immediately after exiting the spinal cord. The first three branches are short, and extend into the closest muscle, facet joint, and intervertebral disc. The fourth branch may be much longer and fork several times until it terminates somewhere among the body's tissues. Along the way, these branches may rebranch or combine with other nerves.

The branches of the cervical nerve roots send an receive signals from the head and neck, upper extremities (arms/shoulders), and diaphragm. The branches of the thoracic nerve roots send and receive signals from the intercostals muscles, torso and waist, and abdominal muscles. The branches of the lumbar nerve roots send and receive signals from the lower extremities, including the hip, upper leg, lower leg, knee, foot and toes. The branches of the sacral (sacrum) nerve roots also supply information to the knees, feet and toes. The reason for some overlap among the nerve roots, locations, and functions is because of the fact that the branches recombine with other branches from their original root, and also combine with other nerve roots, before they reach their final destination.

The pair of nerve roots that emerge from between the fourth and fifth vertebrae of the lumbar region (called the L4 nerve roots) and the four nerve roots below it (the L5, S1, S2, and S3 nerve roots) merge at hip level, beneath the gluteus maximus muscle. This bundle or combined nerves is known as the sciatic nerve. The sciatic nerve is the thickest nerve of the body, and one runs down each side of the leg. The sciatic nerve travels through the back of the thigh where it branches into two just superior (above) the knee. One of these branches runs down the front of the shin and into the big toe. The other branch divides again, running down the back of the leg into the heel and winding again toward the front of the leg into the smaller toes.

The main sciatic nerve and branches just mentioned are only the primary branches of the sciatic nerve. From these primary branches, the nerve may divide hundreds more times to give our legs and feet the sensations and ability to walk we enjoy today.

We may experience back pain, pain in our legs, or other changes in the senses of our hips, buttocks, and legs, when one or more sections of our sciatic nerve become compressed, or when there is sciatic nerve irritation along one of its branches.