Researchers in the United States say when it comes to treating a herniated disc, there is not much to choose between surgery and an exercise programme.

A herniated disc is most common in the lower back and puts pressure on the spinal nerves, a condition that can be very painful and often affects everyday life.

Surgery for herniated discs is the most common surgical procedure performed in the U.S. for back and leg pain and as herniated discs can improve with time and with exercise, the differences in surgery rates across the U.S., and internationally, led the researchers to question if the operation is appropriate and useful.

The researchers from the Dartmouth Medical School in Hanover, New Hampshire, conducted the study involving more than 1,200 patients at 13 U.S. hospitals.

In the randomized trial, people who did not get the surgery were offered physical therapy, education and counselling on how to do exercises at home, and non-steroidal anti-inflammatory drugs.

They say the results revealed that over time the surgery to remove a bulging back disc or a course of physical therapy both helped ease the pain and discomfort.

With a herniated disk, the doughnut-shaped soft tissue cushioning the vertebra protrudes and impinges on nerves running along the spine and it is a very common problem.

Lead author James Weinstein, who along with colleagues conducted the four-year study, says going on the responses from patients, surgery appeared to provide more relief initially than physical therapy for their sciatica and other pain.

However over a two year period following either treatment, the difference was not statistically significant.

In another study by Eugene Carragee of Stanford University Medical Center, it was shown that the fears of many patients and surgeons that not removing a large herniated disc would lead to a worsening of back problems, neurological breakdown, numbness and paralysis in the legs, buttocks or genitals, were unfounded.

The research is published in the Journal of the American Medical Association.