Exercise keeps bad backs at work, and the type barely matters

Persistent low back pain without an identifiable structural cause is one of the most common reasons people end up off work, and the cost lands on the person as heavily as on the payroll. Exercise is a standard recommendation for this kind of pain, but most trials measure pain scores rather than the outcome that shapes lives: whether people stay in or return to work. This review set out to answer the harder question, asking whether exercise beats usual care on work disability, and if it does, whether any particular type of exercise deserves the credit.

The researchers systematically searched six databases up to August 2008 for randomised controlled trials of exercise in non-acute non-specific low back pain that reported work disability outcomes. Twenty-three trials met the inclusion criteria, and 20 could be combined statistically. That allowed 17 comparisons of exercise against usual care and 11 comparisons between two different exercise interventions. Work disability data were converted to odds ratios and pooled using random-effects models, and meta-regression was used to test whether specific characteristics of the exercise changed the outcome.

In the long term, exercise significantly reduced the odds of work disability compared with usual care, with an odds ratio of 0.66. In the short term the odds ratio was 0.80 and in the intermediate term 0.78, and neither reached statistical significance. Meta-regression found no significant effect of any specific exercise characteristic, meaning no type, dose or setting could be crowned the best. The benefit, in other words, was real but slow to reveal itself, and it was indifferent to the flavour of exercise chosen.

This strengthens the general advice that people with persistent non-specific back pain should keep active, and it extends that advice to an outcome with real economic weight: staying at work. At the same time it complicates the search for a single best rehabilitation programme, since nothing in the data separated one exercise approach from another. The searches ran only to August 2008, so more recent trials are not captured here. Why the benefit appears only in the long term, and which ingredients of an exercise programme matter most, remain open questions.

If your lower back has been grumbling for months and work is getting harder, this is evidence that structured exercise pays off, though the payoff arrives over the long haul rather than within weeks. It is also a reason not to agonise over which programme is best, because nothing in these trials separated one type from another, which leaves room to pick whatever you enjoy and can sustain. As ever, a pooled result describes groups rather than any single back, so individual experiences will vary.