Regular yoga sessions may be an effective way to combat chronic lower back pain, research suggests.
Yoga can help muscle tone
A team from Seattle's Group Health Cooperative Center for Health Studies assessed 101 adults with back pain.
Those who practised weekly 75-minute yoga classes made greater progress than those who took part in strengthening and stretching classes.
The Annals of Internal Medicine study also found yoga was more effective than using a self-care book on back pain.
The researchers found that at the end of 12 weeks patients in the yoga group were better able to do daily activities involving the back.
After another 14 weeks they also reported less pain, and used less pain relieving drugs.
Researcher Dr Karen Sherman said: "Most people have experienced back pain at some point in their lives.
"Sometimes the pain goes away in a few days, but sometimes it lasts for weeks.
"And unfortunately, the treatments offered by modern Western medicine are only modestly effective."
Current treatments for low back pain include pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and muscle relaxants. Exercise is also recommended.
Dr Sherman said: "Although exercise is one of the few proven treatments for chronic low back pain, its effects are often small and we haven't known whether one form is better than another.
"So we designed a study to evaluate the effectiveness and safety of a gentle program of yoga for people with this condition."
It is thought that many people practice yoga to try to relieve back pain - but there has been a lack of firm evidence to prove its worth.
The yoga students in the Seattle study learned 17 poses from viniyoga, a style that is easy to learn and typically allows poses to be adapted for use by various body types.
Dr Sherman stressed that anybody interested in learning yoga for relief of back pain should chose an experienced instructor.
There have been reports suggesting the increasing popularity of yoga has led to a raft of injuries among people who either push themselves too hard, or who do not use a qualified instructor.
Dr Alan Breen, director of the Institute for Musculoskeletal Research And Clinical Implementation, said previous research had suggested that strengthening and stretching exercises were no more effective than other types of exercise for chronic back pain.
However, he said: "Yoga requires learning about exercise as well as doing it, and active treatments, where patients take the initiative, are already recognised to be better than ones where they are just passive recipients.
"But there needs to be more trials of yoga specifically against more effective interventions than exercise to make it highly recommended.
"People with chronic back pain should not, therefore see yoga as a 'magic bullet', but as a useful form of learning and understanding their bodies in a way that gives them an activity they can go to.
"If it doesn't work for their chronic back pain, that doesn't mean that another form of behavioural treatment won't."
Sarah Bazin, of the Chartered Society of Physiotherapists, said: "It is very important that once having achieved relief from back pain that the individual does follow a programme of activity to maintain good posture and exercise in order to strengthen muscles weakened by an often sedentary lifestyle."