BMJ 2008;336:398 (23 February), doi:10.1136/bmj.39464.656007.80 (published 31 January 2008)
Advice to stay active may not be appropriate for people in manual jobs
Every month, back pain affects 18-45% of the adult Western population,1 and the costs to society are between 200 (£150; $290) and 400 per capita per year.2 People who do heavy physical work are particularly susceptible because back problems are likely to be exacerbated when the back is used in its full range of movements.
In the accompanying paper, Martimo and colleagues report a systematic review of the prevention of back pain in people whose jobs involve heavy lifting.3None of the randomised controlled trials or cohort studies included in the reviewfound a positive effect of advice or training in working techniques—with or without lifting equipment—for preventing back pain or consequent disability.
Although the results are disappointing, they are not surprising, because few pathological and anatomical labels(such as a tumour, fracture, inflammatory disease, or acute disc protrusion)can be used to explain the aetiology of back pain.4 After removing the relatively few cases with obvious pathology, most patients are labelled as having non-specific back pain,4 and it is not easy to treat a condition without a clear understanding of its cause. This lack of diagnostic refinement may explain why most randomised controlled clinical trials of the treatment or prevention of back pain show relatively inconclusive results.5
The review by Martimo and colleagues confirms how little we know about how to prevent and treat back pain. This may be because back pain is a symptom and not a disease.Or perhaps the disorder cannot be reversed once it becomes established, so that no treatment could be effective.
Low back pain has been shown to start at puberty.6 7 In adults it is likely to recur or to become persistent,8 9 10 so perhaps we should aim for primary prevention—prevent the problem from occurring in the first place. Studies of prevention should therefore take place before puberty, but such studies are very rare.
So what further research needs to be done? Funding for studies on the causes of disease is harder to obtain than for studies that look at treatment. But we must identify the causes of low back pain before we study how we can prevent it. We would go so far as to suggest that randomised clinical trials of non-specific low back pain should be suspended as they include so many different types of back pain that the results are difficult to interpret.
What then can we do for our patients while we wait for further studies to be performed? The commonly given advice to patients to stay at work and be as physically active as possible may not be appropriate for people whose work involves heavy lifting and who have a history of recurrent back pain and several periods of sick leave. Continuing heavy manual work in their job and increasing leisure time physical activity may not be a good idea as no clearly effective treatment is available.5 A change of job and (prudently) staying active in daily life may be the best way for these patients to regain command of their back and their occupation.
Niels Wedderkopp, associate professor1, Charlotte Leboeuf-Yde, professor2
1 Back Research Centre, Back Centre Funen, Funen Hospital, 5750 Ringe, Denmark, 2 Institute of Sport Science and Clinical Biomechanics, Faculty of Health, University of Southern Denmark, 5230 Odense M, Denmark
Provenance and peer review: Commissioned; not externally peer reviewed.