title: Physical fitness, rather than self-reported physical activities, is more strongly associated with low back pain: evidence from a working population.
abstract: BACKGROUND
  Physical activity is suggested to be important for low back pain (LBP) but a major problem is the limited validity of the measurement of physical activities, which is usually based on questionnaires. Physical fitness can be viewed as a more objective measurement and our question was how physical activity based on self-reports and objective measured levels of physical fitness were associated with LBP.
  
  
  METHODS
  We analyzed cross-sectional data of 1,723 police employees. Physical activity was assessed by questionnaire (SQUASH) measuring type of activity, intensity, and time spent on these activities. Physical fitness was based on muscular dynamic endurance capacity and peak oxygen uptake (VO(2) peak). Severe LBP, interfering with functioning, was defined by pain ratings ≥ 4 on a scale of 0-10.
  
  
  RESULTS
  Higher levels of physical fitness, both muscular and aerobic, were associated with less LBP (OR: 0.54; 95% CI: 0.34-0.86, respectively, 0.59: 95%CI: 0.35-0.99). For self-reported physical activity, both a low and a high level of the total physical activity pattern were associated with an increase of LBP (OR: 1.52; 95%CI: 1.00-2.31, respectively, 1.60; 95%CI: 1.05-2.44).
  
  
  CONCLUSIONS
  These findings suggest that physical activity of an intensity that improves physical fitness may be important in the prevention of LBP.
authors: Research Department Lifestyle and Health, University of Applied Sciences, PO box 85182, 3508 AD, Utrecht, The Netherlands. Hans.Heneweer@hu.nl
authors: Hans
authors: H
authors: Heneweer
authors: H Susan J
authors: HS
authors: Picavet
authors: Filip
authors: F
authors: Staes
authors: Henri
authors: H
authors: Kiers
authors: Luc
authors: L
authors: Vanhees
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D017116:Low Back Pain / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D016495:Police; D057566:Self Report; D055815:Young Adult