Short-term physical risk factors for new episodes of low back pain - Prospective evidence from the South Manchester Back Pain Study

Study Design. A prospective population-based cohort study performed in Sout h Manchester, United Kingdom. Objectives. To determine whether nonoccupational physical activity and indi cators of physical stress on the spine predict low back pain in the short t erm. Summary of Background Data. There is evidence that physical activity outsid e the workplace helps to protect against low back pain in the long term. Ho wever, such activity may injure or stress the spine in the short term. Methods. A baseline survey questionnaire identified 2715 adults, aged 18-75 years, with no low back pain at the time of the survey. Information on pot ential predictors of low back pain also was obtained. New episodes of back pain were identified during the subsequent year. Results. A new low back pain episode occurred in 34% of men and 37% of wome n. Poor general health at baseline was the strongest predictor of a new epi sode of pain (men: relative risk (RR) 1.5, 95% confidence intervals (CI) 0. 8, 2.7; women: RR 2.2, 95% CI 1.2, 4.0). High weight was associated with su bsequent low back pain in women (RR 1.4; 95% CI 1.0, 2.0), but neither heig ht nor weight predicted low back pain in men. A self-rated low level of phy sical activity was not consistently linked with subsequent low back pain, n or were specific nonoccupational physical activities, apart from home-impro vement work in men and regular sports in women. Conclusion. Although some specific activities may be hazardous to the back, physical activity outside the workplace does not increase the short-term r isk of low back pain overall. Leisure-time physical activity is not a hazar d to the back, whereas poor physical health in both genders and heavier wei ght in women do increase the risk of new low back pain episodes in the shor t term.