Routine physiotherapy for mild back pain is no more effective than a single advice session, according to a study.
Some 1.3m people are treated by NHS physiotherapists a year
Researchers at the University of Warwick and Oxford University analysed the treatment of 286 people who had had low back pain for more than six weeks.
Some 144 people had physiotherapy sessions while 142 were given advice about how to remain active.
After 12 months, the British Medical Journal study found no difference in how the two groups felt.
Patients in the therapy group underwent a physical examination by a physiotherapist who then chose a treatment strategy based on their findings, which included joint mobilisation and manipulation, stretching and heat or cold treatment.
Each patient had an average of five sessions.
The advice group had a single session, lasting up to an hour, with the physiotherapist who carried out a physical examination and gave general advice to remain active.
The researchers, funded by the Arthritis Research Campaign, measured the levels of the participants' disability at two, six and 12 months and also asked the patients whether they felt they had benefited.
While the patients in the therapy group were more likely to report benefits, there was no evidence for a long-term effect of the physiotherapy.
After 12 months, there was no difference in the disability scores between the two groups, according to the findings published in the British Medical Journal.
Report co-author Sarah Stewart-Brown, professor of public health at the University of Warwick, told BBC News Online: "The message to take away from this study is that there is no magic wand to curing back pain.
"If you want to get rid of the pain you have to play an active role in the process yourself.
"Almost all physiotherapists will recommend exercise and it should be followed.
"But knowing what I know, I would not go to an physiotherapist if I had back pain."
In an editorial in the BMJ, Dr Domhnall MacAuley, a GP, said the study was not necessarily proof that physiotherapy did not work as the advice session was in fact treatment.
But he questioned whether GPs should be so quick to refer patients for physiotherapy.
Physiotherapists in the NHS treat 1.3 million people for low back pain each year.
Dr MacAuley said: "Back pain is a difficult problem. Referral to physiotherapy is an easy option. It gives the doctor some time, and the patient is having treatment."
And the Chartered Society of Physiotherapy said the advice session was still a form of treatment and both advice and therapy sessions could play a role in treating back pain.