A Pain In The Butt, Literally - A Series On Sciatica - Part 2

In the first part of this series on sciatica, the question, "what is sciatica?" was posed, and then answered. In this second part, the question, "how does it happen" will be answered? This is in an effort to educate the public as to why the term sciatica is used so often, specifically in chiropractic, orthopedic and primary care settings.

Sciatica, as answered in part 1, is an inflammation or irritation of the sciatic nerve. In order to understand how does it happen, one must first understand the anatomy of the region. The sciatic nerve is a large, tortuous nerve that is comprised of nerve roots at the L4 - S3 vertebrae. The nerve roots come together to form a "superhighway" nerve that supplies nearly the whole of the skin of the leg, the muscles of the back of the thigh, and those of the leg and foot (see picture to left).

Nerve roots joining to form the sciatic nerve

Once you understand how large a nerve it truly is, and how far ranging the distribution is, it becomes a little clearer as to how irritation of the nerve can lead to problems as far away as the foot. When an intervertebral disc is "bulging," or "herniated" it implies that the center portion of disc has been pushed out the back of the disc. When this occurs, the bulge or herniation (see below) pushes or compresses against the nerve root that will later join with other nerve roots to form the sciatic nerve.

Just as when you compress anything, transfer from one side to another becomes more difficult. Think of a plastic bag that is inflated. Then compress the middle and try to transfer air from one side to the other. Because of your compression, transfer is made increasingly difficult, even impossible. A nerve operates in the same fashion. When compression occurs, signals that travel back and forth, in addition to the blood flow within the nerve becomes more difficult. Compression can take many forms including pain, altered sensation such as pins and needles, tingling or shooting sensations, and weakness. Herniations and bulging discs are the primary mechanisms by which sciatica occurs, but there are other causes as well, including but not limited to muscle tightness within the hip, bone spurs on vertebrae, spinal stenosis, tumors and even pregnancy.

Images of herniated & bulging discs

If you experience any of these symptoms, make sure you schedule an appointment with Dr. Donohue at Rehabilitation & Spinal Care of Rockford. The office is accepting new patients and can provide relief of this condition and these symptoms. Call (815) 394 0309.