title: No associations between objectively measured physical activity and spinal pain in 11-15-year-old Danes.
abstract: BACKGROUND
  Physical activity is thought to play a role in spinal pain (neck pain, mid back pain, low back pain) in children and adolescents, either as a risk or protective factor, but current evidence is conflicting. The overall aim of this study was to determine the cross-sectional and longitudinal associations between different levels of objectively measured physical activity, i.e. sedentary; moderate and vigorous; vigorous physical activity, and spinal pain in 11-15-year-old Danes.
  
  
  METHODS
  Data were collected at baseline (2010) (n = 906) and at follow-up 2 years later (n = 625) in a school-based prospective cohort study. Physical activity was measured using the Actigraph GT3X Triaxial Activity Monitor, which measures the intensity of physical activity over time. This was worn for 1 week and spinal pain was assessed via e-survey that participants completed during school time. Potential confounders included in the multivariable analyses were sex, anthropometry, physical fitness, social status and psychosocial factors. In the longitudinal study, analyses stratified by baseline pain status were performed.
  
  
  RESULTS
  There were neither cross-sectional nor longitudinal associations between different levels of objectively measured physical activity and spinal pain over the 2-year period.
  
  
  CONCLUSIONS
  Objectively measured physical activity was not associated with spinal pain. However, it remains to be seen whether there is an association over a longer follow-up period. Future research should focus on the more qualitative aspects of physical activity, such as different sports activities.
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.
authors.forename: E
authors.initials: E
authors.lastname: Aartun
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.|Nordic Institute of Chiropractic and Clinical Biomechanics, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Hartvigsen
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.|Dalla Lana School of Public Health, University of Toronto, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Boyle
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Denmark.|Nordic Institute of Chiropractic and Clinical Biomechanics, Denmark.
authors.forename: L
authors.initials: L
authors.lastname: Hestbaek
mesh_terms: D000886:Anthropometry; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D010146:Pain / Q000453:epidemiology*; D010809:Physical Fitness; D011446:Prospective Studies; D057185:Sedentary Behavior; D012737:Sex Factors; D012923:Social Class; D013122:Spinal Diseases / Q000453:epidemiology*; D013177:Sports; D011795:Surveys and Questionnaires