title: What triggers an episode of acute low back pain? A case-crossover study.
abstract: OBJECTIVE
  To investigate a range of transient risk factors for an episode of sudden-onset, acute low back pain (LBP).
  
  
  METHODS
  This case-crossover study recruited 999 subjects with a new episode of acute LBP between October 2011 and November 2012 from 300 primary care clinics in Sydney, Australia. Each participant was asked to report exposure to 12 putative triggers over the 96 hours preceding the onset of back pain. Conditional logistic regression was used to estimate odds ratios (ORs) expressing the magnitude of increased risk with exposure to each trigger.
  
  
  RESULTS
  Exposure to a range of physical and psychosocial triggers significantly increased the risk of a new onset of LBP; ORs ranged from 2.7 (moderate or vigorous physical activity) to 25.0 (distracted during an activity or task). Age moderated the effect of exposure to heavy loads and sexual activity. The ORs for heavy loads for people ages 20, 40, or 60 years were 13.6, 6.0, and 2.7, respectively. The risk of developing back pain was greatest between 7:00 AM and noon.
  
  
  CONCLUSIONS
  Transient exposure to a number of modifiable physical and psychosocial triggers substantially increases risk for a new episode of LBP. Triggers previously evaluated in occupational injury studies, but never in LBP, have been shown to significantly increase risk. These results aid our understanding of the causes of LBP and can inform the development of new prevention approaches.
authors: The University of Sydney, Sydney, Australia; Federal University of Minas Gerais, Minas Gerais, Brazil.
authors: Daniel
authors: D
authors: Steffens
authors: Manuela L
authors: ML
authors: Ferreira
authors: Jane
authors: J
authors: Latimer
authors: Paulo H
authors: PH
authors: Ferreira
authors: Bart W
authors: BW
authors: Koes
authors: Fiona
authors: F
authors: Blyth
authors: Qiang
authors: Q
authors: Li
authors: Christopher G
authors: CG
authors: Maher
mesh_terms: D059787:Acute Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control / Q000523:psychology; D000328:Adult; D000367:Age Factors; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D017116:Low Back Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009517:New South Wales; D016017:Odds Ratio; D010147:Pain Measurement; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult