title: Relationship between ambulatory performance and self-rated disability in patients with lumbar spinal stenosis.
abstract: METHODS
  A cross-sectional study.
  
  
  OBJECTIVE
  To identify the relationship between performance measures derived from accelerometry and subjective reports of pain, disability, and health in patients with lumbar spinal stenosis (LSS).
  
  
  BACKGROUND
  Accelerometers have emerged as a measure of performance, providing the ability to characterize the pattern and magnitude of real-life activity, and sedentarism. Pain and loss of function, particularly ambulation, are common in LSS. The extent to which pain, perceived disability, and self-rated health relate to performance in patients with LSS is not well known.
  
  
  METHODS
  Data regarding self-reported pain, disability (Oswestry Disability Index, Roland-Morris Disability Questionnaire, and Disabilities of the Arm, Shoulder, and Hand), and health (36-Item Short Form Health Survey [SF-36]) were collected from patients with LSS (n = 33). Physical activity, ambulation, and inactivity performance measures were derived from 7-day accelerometer records. Correlation and stepwise regression were used.
  
  
  RESULTS
  The physical function subscale of the SF-36, a non-pathology-specific outcome, had the best overall correlation to physical activity and ambulation (average r = 0.53) compared with pain (average r = 0.32) and disability (average r = -0.45) outcomes. Stepwise regression models for performance were predominantly single-variable models (4 of 8 models); pain was not selected as a predictor. A second non-pathology-specific outcome, the Disabilities of Arm Shoulder and Hand, improved the prediction of performance in 5 of 8 models.
  
  
  CONCLUSIONS
  Subjective measures of pain and disability had limited ability to account for real-life performance in patients with LSS. Future research is required to identify determinants of performance in patients with LSS because barriers to activity may not be disease-specific.
authors.affiliation: School of Medical Rehabilitation, University of Manitoba, Winnipeg, Manitoba, Canada. robertpryce@gmail.com
authors.forename: Rob
authors.initials: R
authors.lastname: Pryce
authors.forename: Michael
authors.initials: M
authors.lastname: Johnson
authors.forename: Michael
authors.initials: M
authors.lastname: Goytan
authors.forename: Steven
authors.initials: S
authors.lastname: Passmore
authors.forename: Neil
authors.initials: N
authors.lastname: Berrington
authors.forename: Dean
authors.initials: D
authors.lastname: Kriellaars
mesh_terms: D061725:Accelerometry / Q000379:methods; D000368:Aged; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006801:Humans; D016014:Linear Models; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D057566:Self Report; D013130:Spinal Stenosis / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology*