title: The NIOSH lifting equation and low-back pain, Part 1: Association with low-back pain in the backworks prospective cohort study.
abstract: OBJECTIVE
  The aim of this study was to evaluate relationships between the revised NIOSH lifting equation (RNLE) and risk of low-back pain (LBP).
  
  
  BACKGROUND
  The RNLE is commonly used to quantify job physical stressors to the low back from lifting and/or lowering of loads. There is no prospective study on the relationship between RNLE and LBP that includes accounting for relevant covariates.
  
  
  METHODS
  A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current LBP were obtained at baseline. The cohort was followed monthly to ascertain development of LBP and quarterly to determine changes in job physical exposure. The relationship between LBP and peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression.
  
  
  RESULTS
  Point and lifetime prevalences of LBP at baseline were 7.1% and 75.1%, respectively. During follow-up, there were 123 incident LBP cases. Factors predicting development of LBP included job physical exposure (PLI and PCLI), history of LBP, psychosocial factors, and housework. In adjusted models, risk (hazard ratio [HR]) increased per-unit increase in PLI and PCLI (p = .05 and .02; maximum HR = 4.3 and 4.2, respectively). PLI suggested a continuous increase in risk with an increase in PLI, whereas the PCLI showed elevated, but somewhat reduced, risk at higher exposures.
  
  
  CONCLUSIONS
  Job physical stressors are associated with increased risk of LBP. Data suggest that the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.
authors.forename: Arun
authors.initials: A
authors.lastname: Garg
authors.forename: Sruthi
authors.initials: S
authors.lastname: Boda
authors.forename: Kurt T
authors.initials: KT
authors.lastname: Hegmann
authors.forename: J Steven
authors.initials: JS
authors.lastname: Moore
authors.forename: Jay M
authors.initials: JM
authors.lastname: Kapellusch
authors.forename: Parag
authors.initials: P
authors.lastname: Bhoyar
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Thiese
authors.forename: Andrew
authors.initials: A
authors.lastname: Merryweather
authors.forename: Gwen
authors.initials: G
authors.lastname: Deckow-Schaefer
authors.forename: Donald
authors.initials: D
authors.lastname: Bloswick
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Malloy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007899:Leisure Activities; D017770:Lifting / Q000009:adverse effects*; D017116:Low Back Pain / Q000453:epidemiology* / Q000209:etiology* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009314:National Institute for Occupational Safety and Health, U.S.; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology* / Q000523:psychology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology