title: The prevalence of low back pain among former elite cross-country skiers, rowers, orienteerers, and nonathletes: a 10-year cohort study.
abstract: BACKGROUND
  Some cross-sectional studies have suggested that the prevalence of low back pain (LBP) may be high among endurance athletes with repetitive back loading, but there are no large, prospective cohort studies addressing this issue.
  
  
  OBJECTIVE
  To compare the prevalence of symptoms of low back pain (LBP) among former endurance athletes with different loading characteristics on the lumbar region: cross-country skiing (flexion loading), rowing (extension loading), and orienteering (no specific loading), as well as a nonathletic control group.
  
  
  METHODS
  Cohort study; level of evidence, 2.
  
  
  METHODS
  Self-reported questionnaire on LBP adapted for sports based on standardized Nordic questionnaires for musculoskeletal symptoms. Responders were 173 rowers, 209 orienteerers, 242 cross-country skiers, and 116 control subjects (88% of the original cohort).
  
  
  RESULTS
  There were no group differences between the athletic groups and the control group with regard to the 2 main outcomes: reported LBP the previous 12 months (P = .66) and frequent LBP the past year (>30 days with LBP) (P = .14). More rowers than orienteerers reported frequent LBP the past year (adjusted OR = 2.32; CI, 1.02-5.28). Occupational changes due to LBP were reported more often by rowers (13%) than skiers (7%) and orienteerers (3%) (P = .002). More rowers and skiers reported having received outpatient medical assistance than orienteerers or controls. A training volume >550 h/y was a risk factor for reporting LBP during the previous 12 months compared with a training volume <200 h/y (adjusted OR = 2.51; CI, 1.26-5.02). A previous episode with LBP was associated with LBP later in life (adjusted OR = 3.02; CI, 2.22-4.10).
  
  
  CONCLUSIONS
  Low back pain was not more common among former endurance athletes with specific back loading compared with non-athletes. The results indicate that years of prolonged and repetitive flexion or extension loading in endurance sports does not lead to more LBP. However, a large training volume in the past year and previous episodes with LBP are risk factors for LBP. Comparing the sports of rowing, cross-country skiing, and orienteering, it appears that whereas orienteering is protective, rowing can provoke LBP.
authors.affiliation: Oslo Sports Trauma Research Centre, Department of Sports Medicine, Norwegian School of Sport Sciences, Norway. idastangefoss@hotmail.com
authors.forename: Ida Stange
authors.initials: IS
authors.lastname: Foss
authors.forename: Ingar
authors.initials: I
authors.lastname: Holme
authors.forename: Roald
authors.initials: R
authors.lastname: Bahr
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D015995:Prevalence