Back pain martyrs have suffered for years on hard beds, even planks of wood. They shouldn't have taken that lying down

Research has revealed that softer mattresses are better for millions of people in agony

Hard mattresses, which have for years been prescribed by doctors for patients suffering from back pain, could do far less good than softer beds, research has shown.

Traditional medical wisdom dictates that hard beds help to alleviate back pain, and 75 per cent of orthopaedic physicians still recommend a firm mattress.

But results of a study published in The Lancet today overturn such orthodoxies. Researchers in Spain found that patients who slept on a "medium-firm" mattress suffered less lower-back pain in bed and during the day than those on a "firm" mattress. The reason may be that softer mattresses put less pressure on the shoulders and hips and allow people to sleep more naturally.

The study is the first of its kind and is likely to persuade many doctors to change their advice to patients with back trouble completely.

Jenny McConnell, a back pain specialist at the University of Melbourne, said: "These findings come as a relief to clinicians who are not only struggling with the day-to-day management of patients with chronic low-back pain but are also constantly bombarded by the lack of efficacy of therapeutic interventions. Until now there has been little empirical evidence to support a clinician's recommendations."

Researchers in Spain recruited 313 volunteers who had suffered chronic lower-back pain for at least three months. The volunteers were randomly divided into two groups.

One group was given a new "firm" mattress with a rating of 2.3 out of ten on a European scale of mattress softness. The other group was given a "medium-firm" mattress, with a rating of 5.6.

Neither group was told which mattress they had received and the mattresses, which looked identical, were installed in the participants' homes in the same way by the same workers, who were not told which type they were delivering.

Existing mattress support bases were replaced with a firm base if the original base offered less than 50 per cent support for the mattress.

Patients were assessed at the start of the trial and again three months later, and were also asked to assess every day on a scale of one to ten the intensity of pain they experienced while lying in bed, the intensity of pain on rising, and the degree of disability suffered throughout the day.

At the end of the 90-day trial participants in both groups had experienced improvements in their back pain compared with when sleeping on their old mattresses, but there were more significant improvements among those on medium-firm beds.

The condition of those who suffered back pain while lying in bed improved by 70 per cent on firm mattresses and 80 per cent on medium-firm mattresses. The ability of the participant to move around easily during the day increased by 30 per cent for firm mattresses and 50 per cent for medium-firm mattresses.

Overall, patients who used medium-firm mattresses were twice as likely to report the easing of lower-back pain while lying in bed, and when getting out of bed. They were also less likely to need pain-killing drug treatment.

Dr Francisco Kovacs, of the Kovacs Foundation in Palma de Mallorca, who led the study, said that the results could change the way that treatment is given. "Our findings stress that recommendations for daily living, such as what kind of mattress to use, may have a relevant effect on the clinical course of low-back pain," he said.

"Although patients were unaware of the type of mattress they were receiving, they generally perceived correctly the firmness of their mattress. The general belief that 'harder means better' reduced the positive effect of the medium-firm mattress in the crude analysis, which in turn is consistent with the importance of psychosocial factors in chronic low-back pain."

Professor Maureen Simmonds, the head of rehabilitation sciences at the University of Southampton, said that the study was a useful addition to knowledge in the area. "In the past, back pain has often been misunderstood and mismanaged," she said.

"One of the difficulties with mattresses has been that people have been unable to choose which is best for their back before having to buy it. This at least gives some sort of advice to doctors based on research."

Dr McConnell said that the next step was to try to identify scientifically why slightly softer beds were better. "Perhaps less pressure on the shoulders and hips from the mattress of medium firmness could allow individuals to remain in the foetal position, which may in turn be better for their back symptoms on rising," she said.

"The underlying mechanisms for the improvement in symptoms of low-back pain with the mattress of medium firmness certainly provide many areas for future investigation."