title: Aerobic fitness in patients at work despite recurrent low back pain: a cross-sectional study with healthy age- and gender-matched controls.
abstract: OBJECTIVE
  The aims of this study were to compare the aerobic fitness level of working patients who have recurrent low back pain with those of healthy age- and gender-matched controls, and to investigate the relationship of aerobic fitness level with pain intensity, general health, perceived disability, fear-avoidance beliefs and self-efficacy.
  
  
  METHODS
  A total of 57 patients with recurrent low back pain, with a mean of 10 years' pain duration and 57 healthy controls performed a sub-maximal Astrand cycle test. Predicted maximum oxygen consumption was calculated and compared. Correlations between the low back pain patients' predicted aerobic fitness level and the assessed variables were calculated.
  
  
  RESULTS
  The women with low back pain had lower predicted aerobic fitness levels than the healthy women (p<0.05). For the men there was no such difference. Multiple regression analysis showed that age, gender, body mass index and self-efficacy were associated with the predicted aerobic fitness level.
  
  
  CONCLUSIONS
  This study suggests no overall difference in predicted aerobic fitness level for a sample of subjects with recurrent low back pain compared with healthy controls. This is perhaps because all the patients were still at work despite the pain. The results indicate, however, that the factors associated with aerobic fitness differ between men and women.
authors.affiliation: Ortoped Medicinskt Center, Care Sciences and Society, Division of Physiotherapy, Karolinska Institutet, Stockhlom, Sweden. eva.rasmussen.barr@ki.se
authors.forename: Eva
authors.initials: E
authors.lastname: Rasmussen-Barr
authors.forename: Lena
authors.initials: L
authors.lastname: Lundqvist
authors.forename: Lena
authors.initials: L
authors.lastname: Nilsson-Wikmar
authors.forename: Therese
authors.initials: T
authors.lastname: Ljungquist
mesh_terms: D000328:Adult; D000367:Age Factors; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010147:Pain Measurement; D010809:Physical Fitness / Q000502:physiology*; D012008:Recurrence; D020377:Self Efficacy; D012737:Sex Factors