People suffering from chronic non-specific lower back pain can find solace in yoga, say researchers, adding that yoga asanas under proper guidance can help reduce pain and allow movement in such people over the short term.

The trials for the study were conducted in India, the UK and the US. All participants had chronic non-specific lower back pain.

"Our findings suggest that yoga exercise may lead to reducing the symptoms of lower back pain by a small amount," said lead author Susan Wieland from Centre for Integrative Medicine at University of Maryland School of Medicine.

"At the moment we only have low to moderate quality evidence for the effects of yoga before six months as a type of exercise for helping people with chronic lower back pain," Wieland added.

The yoga exercises practised in the studies were developed for low back pain and people should also remember that in each of the studies we reviewed, the yoga classes were led by experienced practitioners.

The study, published in the journal Cochrane Library, summarised the results of 12 randomised trials from 1,080 men and women with an average age between 34 and 48.

The Cochrane researchers included studies that compared practising yoga in a class to not doing any back-focused exercise, or to other forms of exercise.

Lower back pain is a common health problem and is usually treated with self-care and over-the-counter medication. For some people, it may last for three months or more, and at this point it is considered "chronic".

The Review found that compared to no exercise, practising yoga might improve back-related function and may also reduce symptoms of lower back pain by a small amount in the first six to 12 months.

"The findings will help people make more informed choices about their future treatment options," the authors wrote.

However, yoga may cause an increase in back pain in some people.

About 5 per cent or more yoga participants experienced increased back pain, although this may be similar to the risk of having side effects from other back-focused exercise.