title: Accelerometry as a measure of walking behavior in multiple sclerosis.
abstract: OBJECTIVE
  Accelerometry has been identified as a possible ecologically valid and objective approach for measuring community ambulation in multiple sclerosis (MS). This study provides a validation of accelerometer output based on associations with Expanded Disability Status Scale (EDSS), Patient Determined Disease Steps (PDDS) Scale, and Multiple Sclerosis Walking Scale-12 (MSWS-12) scores, timed 25-foot walk (T25FW) and 6-min walk (6MW) performance, oxygen cost (O(2) cost) of walking, and spatial and temporal parameters of gait.
  
  
  METHODS
  256 persons with MS completed the PDDS and MSWS-12, underwent an examination for the generation of an EDSS score, undertook two T25FW tests and a 6MW while wearing a portable metabolic unit for measuring the O(2) cost of walking, completed two trials of comfortable walking on a GAITRite electronic walkway for measuring spatial and temporal parameters of gait, and then wore an Actigraph accelerometer during the waking hours of a 7-day period.
  
  
  RESULTS
  The accelerometer output was significantly correlated with EDSS (ρ = -0.522), PDDS (ρ = -0.551), and MSWS-12 (ρ = -0.617) scores, T25FW (ρ = -0.595) and 6MW (ρ = 0.630) performance, and O(2) cost of walking (ρ = -0.457). Regarding gait parameters, the accelerometer output was significantly correlated with velocity (ρ = 0.420), cadence (ρ = 0.349), step time (ρ = -0.353), step length (ρ = 0.395), double support (ρ = -0.424), and single support (ρ = 0.400).
  
  
  CONCLUSIONS
  We provide comprehensive evidence from a large sample of persons with MS that further supports accelerometry as a measure of walking behavior.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, USA. robmotl@illinois.edu
authors.forename: R W
authors.initials: RW
authors.lastname: Motl
authors.forename: L
authors.initials: L
authors.lastname: Pilutti
authors.forename: B M
authors.initials: BM
authors.lastname: Sandroff
authors.forename: D
authors.initials: D
authors.lastname: Dlugonski
authors.forename: J J
authors.initials: JJ
authors.lastname: Sosnoff
authors.forename: J H
authors.initials: JH
authors.lastname: Pula
mesh_terms: D061725:Accelerometry; D000328:Adult; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009103:Multiple Sclerosis / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D016138:Walking / Q000502:physiology*