It is the first time the National Institute for Health and Clinical Excellence has explicitly backed the use of complementary therapies. The rationing watchdog said evidence suggests they help and will be cost effective if doctors stop providing less proven back services like X-rays.

The move was welcomed by some charities and experts but criticised by others.  Low back pain is a very common problem affecting one in three adults in the UK each year, with an estimated 2.5 million people seeking help from their GP.  For many people the pain goes away in days or weeks. But for some, the pain can persist for a long time and become debilitating.

NICE says anyone whose pain persists for more than six weeks and up to a year should be given a choice of several treatments, because the evidence about which works best is uncertain.  Complementary therapies In addition to painkillers and regular advice to stay active and carry on with normal activities as much as possible, patients, together with their doctor, can decide to opt one of three complementary treatments.

This includes up to eight exercise sessions or 10 sessions of acupuncture over 12 weeks, or a course of manual therapy, which includes up to nine sessions of spinal manipulation, mobilisation or massage. Professor Peter Littlejohns, NICE Clinical and Public Health Director said NHS providers now had the opportunity to look at the services they provide and decide what changes are needed.

He said: "There is variation in current clinical practice, so this new NICE guideline means that for the first time we now have the means for a consistent national approach to managing low back pain.  "Importantly, patients whose pain is not improving should have access to a choice of different therapies including acupuncture, structured exercise and manual therapy."

Patients who fail to benefit from their first choice may be offered another of these options, he said.  If that doesn't work, they can try an intensive treatment programme combining exercise and psychological therapy.

Contentious He said the costs to the NHS would be minimal - in the order of £77,000 - because they are offset by the savings in terms of reducing future disability and healthcare needs and moving away from treatments with little supportive evidence.

The guidelines, which apply to England and Wales, say doctors should no longer offer spinal x-rays or MRI scans or injections of therapeutic substances into the back for non-specific low back pain.  The Chartered Society of Physiotherapy welcomed the guidelines, as did Dr Dries Hettinga of the charity BackCare.

He said: "This offers a real choice for patients.  "This guideline will help patients understand what treatment and care can help them with their back pain and shows that there can be a positive outlook for treating this condition."

But others were critical of the recommendations.  Professor Edzard Ernst, an expert in complementary medicine at Peninsula Medical School, said he was surprised by the guidance and particularly by NICE's recommendation of spinal manipulation.

"It feels as though the panel was biased in favour of this approach thus over-rating its effectiveness and under-estimating its risks which can be considerable. In my view, a critical risk benefit analysis of the most reliable data fails to come out in favour of chiropractic.  "We must remember that no optimally effective treatment for back pain exists."