Both weekly yoga classes and regular stretching classes eased pain and improved functioning in people with chronic lower back ailments, according to a US study.

The study, published in the Archives of Internal Medicine, looked at over 200 adults with lower back pain and found that participants in both types of classes reported more improvement in symptoms after three months than patients who were only given a book with advice on preventing and managing pain.

"Here is an option that is worth trying," said Karen Sherman from the Group Health Research Institute in Seattle, who led the study.

Finding that yoga and stretching had about equal effects means it was probably the stretching in yoga, and not the relaxation or breathing components of the practice, that helped improve functioning and pain symptoms, researchers said.

For the study, they divided 228 adults with long-lasting back pain into three groups.

Patients in the first two groups went to either weekly yoga or stretching classes for 12 weeks and were asked to practice on their own between the classes, which focused on stretching and strengthening the lower back and legs.

Patients in the third group were given a book with back pain-related exercise and lifestyle advice, and information on managing flare-ups.

After the 12-week program, people who had gone to the group classes reported significantly lower scores on a questionnaire measuring how much pain interferes with daily activities.

The questionnaire rated daily "disability" level on a scale of zero to 23, with 23 being the most severe. At the 12-week mark, the exercise groups had dropped from an initial average score of 10 in the yoga group or nine in the stretching group to between four and five in both groups.

The people who received the book started with an average score of nine and at 12 weeks had dropped to about a seven.

Sixty percent of people in the yoga group reported improvements in pain, compared to 46 percent in the stretching classes and just 16 per cent of people who only got the books.

Three months after the end of classes, symptom improvements were similar in people who had done either stretching or yoga, and were better than in the non-exercise group.

"We've known for a while ... that exercise is good for back pain," said Timothy Carey, from the University of North Carolina, Chapel Hill, who wrote a commentary published with the study.

"Almost anyone with back pain can benefit from stretching exercises."

- Reuters