title: The influence of self-reported leisure time physical activity and the body mass index on recovery from persistent back pain among men and women: a population-based cohort study.
abstract: BACKGROUND
  There is limited knowledge about leisure time physical activity and the body mass index (BMI) as prognostic factors for recovery from persistent back pain. The aim of this study was to assess the influence of leisure time physical activity and BMI on recovery from persistent back pain among men and women in a general population.
  
  
  METHODS
  The study population (n=1836) in this longitudinal cohort study consisted of participants reporting persistent back pain in the baseline questionnaire in 2002-2003. Data on leisure time physical activity, BMI and potential confounders were also collected at baseline. Information on recovery from persistent back pain (no back pain periods ≥ 7 days during the last 5 years) was obtained from the follow-up questionnaire in 2007. Log-binomial models were applied to calculate Risk Ratios with 95 percent Confidence Intervals (CI) comparing physically active and normal weight groups versus sedentary and overweight groups.
  
  
  RESULTS
  Compared to a sedentary leisure time, all measured levels of leisure time physical activity were associated with a greater chance of recovery from persistent back pain among women. The adjusted Risk Ratios was 1.46 (95% CI: 1.06, 2.01) for low leisure time physical activity, 1.51 (95% CI: 1.02, 2.23) for moderate leisure time physical activity, and 1.67 (95% CI: 1.08, 2.58) for high leisure time physical activity. There were no indications that leisure time physical activity influenced recovery among men, or that BMI was associated with recovery from persistent back pain either among men or among women.
  
  
  CONCLUSIONS
  Regular leisure time physical activity seems to improve recovery from persistent back pain among women.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Box 210, Stockholm SE-17177, Sweden. tony.bohman@ki.se.
authors.forename: Tony
authors.initials: T
authors.lastname: Bohman
authors.forename: Lars
authors.initials: L
authors.lastname: Alfredsson
authors.forename: Johan
authors.initials: J
authors.lastname: Hallqvist
authors.forename: Eva
authors.initials: E
authors.lastname: Vingård
authors.forename: Eva
authors.initials: E
authors.lastname: Skillgate
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D020127:Recovery of Function; D012307:Risk Factors; D057566:Self Report; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology