title: Accuracy, reliability, and validity of a spatiotemporal gait analysis system.
abstract: BACKGROUND
  Making evidence-based decisions in the clinical management of gait dysfunction requires the ability to measure spatiotemporal gait variables validly and reliably. This study examined the accuracy, reliability, and validity of a clinical gait analysis system that is relatively inexpensive and portable, the GaitMat II (GM).
  
  
  METHODS
  The trustworthiness of measures taken with the GM was investigated by comparing the placement of the switches on three different GM systems. Measures taken with the GM system were compared with the same measures taken simultaneously with the Vicon motion analysis system, using a repetitive dynamic signal presented to both systems.
  
  
  RESULTS
  Variability was present in the placement of switches on the surfaces of different GM systems. The variability in switch placement was much less than the normal variability of most gait variables measured with the GM. Excellent agreement was found between the GM and Vicon systems for timing variables but poor agreement was found for distance variables. The mean difference between the GM and Vicon measures for distance variables would have little clinical significance in adults for distance measures such as step length or stride length.
  
  
  CONCLUSIONS
  The results of these studies support the reliability and validity of the GaitMat II as a clinical gait analysis tool.
authors.affiliation: Physical Therapy Department, College Misericordia, 301 Lake Street, Dallas, PA 18612, USA. sbarker@misericordia.edu
authors.forename: Susan
authors.initials: S
authors.lastname: Barker
authors.forename: Rebecca
authors.initials: R
authors.lastname: Craik
authors.forename: William
authors.initials: W
authors.lastname: Freedman
authors.forename: Nira
authors.initials: N
authors.lastname: Herrmann
authors.forename: Howard
authors.initials: H
authors.lastname: Hillstrom
mesh_terms: D001696:Biomechanical Phenomena / Q000295:instrumentation* / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005684:Gait / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation* / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014159:Transducers