More than 80% of Americans will have back pain at some point in their life -- whether from injury, overuse, or as a result of the degenerative process that accompanies aging. Chronic low back pain is frustrating, not only because of the severe pain but also because it can be difficult to effectively treat.

A particularly common cause of this pain is a herniated disk, also referred to as a "slipped disk." The usual conventional medical solutions have been anti-inflammatory medications, muscle relaxants, injections, physical therapy, and surgery, all of which take an extended amount of time to take effect and which may not work for everyone. Recently, a novel type of treatment has been gaining favor. It is a non-surgical, non-invasive treatment for herniated disks called spinal decompression.

Your spine consists of bones, called vertebrae, each of which is stacked one upon the other. The vertebrae are separated from each other by rubbery discs that act as shock absorbers.

The disks are constructed like hard donuts filled with a jelly-like material in the center. Over time, the strong fibrous cartilage (the donut shell) can weaken, allowing the jelly-like material (nucleus pulposus) to bulge. If it's a mild bulge, it is not painful. However if the bulge extends out far enough, it can irritate nerves and lead to pain. But more seriously, a disc can herniate- explode through the shell causing disc material to pour out and press on spinal nerves. This can cause excruciating pain and significant nerve damage.

One of the first devices used for spinal decompression was approved by the FDA in 1995. Because spinal decompression requires special expertise and expensive equipment, few physicians have offered this treatment -- but the procedure is becoming more commonly available.

Here's how it work...the patient lies on a comfortable table made specifically for decompression, comfortably strapped down with a pelvis and torso harness that looks like a girdle. "It is a high-tech traction device," Dr. Wei explained. "It works by slowly and comfortably creating traction by pulling and holding for one minute. Then, intermittently, it releases. It is believed that this creates a negative pressure, or a vacuum within the disk, which then sucks back the bulging or herniated disk material which was displaced," he goes on to explain. With less pressure inside the disk, and therefore less on the spinal nerves, pain often diminishes and might even go away - sometimes altogether. To maintain the benefit, however, numerous sessions may be required.

This theory is that this technique also allows nutrient and oxygen-rich fluid to travel to the area where there is less pressure, stimulating the healing process. Most patients either sleep or listen to a CD during the treatment, Dr. Wei added. Each session takes about 30 minutes and a typical treatment program may take between 20 to 30 sessions.

Critics contend that there are no long-range, well-designed studies looking at efficacy over time, but there has been some research on the treatment and the results are promising. In one study published in Neurological Research(2001), researchers reported that a spinal decompression therapy called VAX-D produced a success rate of 68.4%, compared with 0% for a placebo therapy in treatment of chronic low back pain. Another study demonstrated that a similar device called the Spina internal disc decompression unit or IDD had an 86% response rate. And... a recent study from a team of researchers at the University of Illinois and Rome found a 71% success rate for treatment of herniated disk and other causes of low back pain using spinal decompression, with "success" defined as a reduction in pain to 0 or 1 on a scale of 0 to 5.

Dr. Wei noted that some people get much benefit from spinal decompression while others do not. He emphasized that it is not an option for everyone. "It's contraindicated for a person who has metal implants in the spine or who has had a spinal fusion," he warned. And it is not recommended for patients who have spinal instability or who have severe untreated osteoporosis. It's better for people with a single-disk herniation than those who have multiple herniations. Also, people who are morbidly obese and/or who smoke probably won't find much relief from spinal decompression.

The procedure is thought to be safe, though there is not a lot of hard science data supporting its efficacy. If you do decide to seek out this form of treatment, it's safest and best to do so with the recommendation of your rheumatologist, who can help you determine whether it might work in your situation.