title: Classifying subgroups of chronic low back pain patients based on lifting patterns.
abstract: OBJECTIVE
  To compare self-reported measures of chronic lower back pain (CLBP) patients who were assigned to 2 subgroups based on their lifting patterns performed during a repetitive lifting task.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Research laboratory
  
  
  METHODS
  CLBP subjects (n=81) and pain-free controls (n=53).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Measures of lifting patterns and self-reported disability, pain, and psychosocial aspects.
  
  
  RESULTS
  Two CLBP subgroups were found: 1 group that lifts similarly to control subjects (n=35) and 1 group that lifts very differently from controls (n=46). The CLBP group that lifted differently than controls reported higher pain intensity (P=.005), higher pain severity (P=.025), and lower self-efficacy (P=.013) than the CLBP group that lifted similarly to controls.
  
  
  CONCLUSIONS
  A classification system based on lifting patterns identified 2 CLBP subgroups that were significantly different on lifting and self-reported measures, indicating the importance of physical functioning measures in classification systems.
authors.affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. jslaboda@temple.edu
authors.forename: Jill C
authors.initials: JC
authors.lastname: Slaboda
authors.forename: J Robert
authors.initials: JR
authors.lastname: Boston
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Rudy
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Lieber
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002908:Chronic Disease; D005260:Female; D006801:Humans; D017770:Lifting; D017116:Low Back Pain / Q000145:classification* / Q000503:physiopathology; D008297:Male; D008390:Markov Chains; D015999:Multivariate Analysis; D013647:Task Performance and Analysis