title: Cross-sectional view of factors associated with back pain.
abstract: OBJECTIVE
  To examine the factors associated with back pain within a working population.
  
  
  METHODS
  A cross-sectional survey of employees using a self-administered questionnaire and physical fitness tests. This study assessed 10,321 participants (6,251 male and 4,070 female) of two nationwide companies throughout Switzerland between 1996 and 1998. The participation rate was 41%.
  
  
  RESULTS
  Of the participants, 4,945 (48%) suffered mild back pain and 696 (7%) suffered severe back pain. Reported "stress" was associated with back pain of any intensity. Abdominal muscle strength was inversely associated with severe back pain, while physical activity was non-linearly associated with severe back pain. Smoking was directly associated with any intensity of back pain. The variables gender, obesity, strength of the abdominal musculature and frequency of physical activity were insignificant for back pain of any intensity in multivariate analyses.
  
  
  CONCLUSIONS
  Our results confirm the association of back pain with physical and behavioural factors. The non-linear relationship between physical activity and back pain may need further examination. Performing any kind of sport three to four times a week appears optimal.
authors.affiliation: Institute of Social and Preventive Medicine, University of Zurich, Sumatrastrasse 30, 8006 Zurich, Switzerland.
authors.forename: Chung-Yol
authors.initials: CY
authors.lastname: Lee
authors.forename: Renato
authors.initials: R
authors.lastname: Kratter
authors.forename: Nicole
authors.initials: N
authors.lastname: Duvoisin
authors.forename: Aydin
authors.initials: A
authors.lastname: Taskin
authors.forename: Julian
authors.initials: J
authors.lastname: Schilling
mesh_terms: D000009:Abdominal Muscles; D000328:Adult; D001416:Back Pain / Q000209:etiology*; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006293:Health Promotion; D006801:Humans; D008019:Life Style; D008297:Male; D009784:Occupational Diseases / Q000209:etiology*; D011795:Surveys and Questionnaires; D013557:Switzerland; D017132:Workplace