title: Association between back pain and physical fitness in adolescents.
abstract: METHODS
  A cross-sectional study of 9413 adolescents.
  
  
  OBJECTIVE
  To study the associations between back pain, physical activity, and physical fitness.
  
  
  BACKGROUND
  A high physical fitness level, and especially muscle endurance in the back muscles, is associated with lower risk of back pain, but little is known about other types of physical fitness and back pain in adolescents.
  
  
  METHODS
  A cross-sectional study of 3956 boys and 5457 girls 17 years of age. The associations between self-reported back pain and different types of physical fitness and self-reported physical activity were analyzed in high schoolchildren in Denmark.
  
  
  RESULTS
  Back pain was reported by 43% of the girls and 37% of the boys. Back pain was associated with low isometric muscle endurance in the back extensors, and the highest quartile had a lower risk of back pain (odds ratio = 0.71; 95% confidence interval, 0.62-0.82) within the last month. No associations were found to aerobic fitness, functional strength, flexibility, or physical activity level after adjustment for muscle endurance. More girls than boys experienced back pain, and it was more common in taller adolescents.
  
  
  CONCLUSIONS
  Children with high isometric muscle endurance were less likely to report back pain. No other measures of physical fitness or level of self-reported physical activity were linked to back pain reporting.
authors.affiliation: Norwegian School of Sport Sciences, Oslo, Norway. lars.bo.andersen@nih.no
authors.forename: Lars
authors.initials: L
authors.lastname: Bo Andersen
authors.forename: Niels
authors.initials: N
authors.lastname: Wedderkopp
authors.forename: Charlotte
authors.initials: C
authors.lastname: Leboeuf-Yde
mesh_terms: D000293:Adolescent; D001415:Back / Q000502:physiology; D001416:Back Pain / Q000453:epidemiology* / Q000503:physiopathology*; D001827:Body Height; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D009043:Motor Activity; D010807:Physical Endurance; D010809:Physical Fitness; D012307:Risk Factors