title: Assessment of the test-retest reliability of a foot placement accuracy protocol in assisted-living older adults.
abstract: BACKGROUND
  This study assessed the test-retest reliability of a foot placement accuracy protocol in a population of assisted-living elderly. The goal was to evaluate the execution of foot placement performance with increasing complexity of the walking condition.
  
  
  METHODS
  Twenty-five elderly participants (5 males, 20 females, 80.4±8.6 years) were assessed by one observer in two sessions with 48 h between the measurements. Participants walked at self-selected pace along a pathway with three different walking conditions composed of two rectangular foam target locations and an obstacle on the walking surface. The main outcome measures were foot placement distance error, intra-class correlation coefficients (ICC), and the smallest detectable difference (SDD).
  
  
  RESULTS
  Mean absolute values of the foot placement distance errors were 14.0±4.5 mm for medio-lateral deviation and 27.2±2.1 mm for anterior-posterior deviation, respectively. ICC values for test-retest reliability showed 'fair to good' to 'excellent' reliability across all conditions with values ranging from 0.63 to 0.94. SDD values were between 3.6 and 37.3mm.
  
  
  CONCLUSIONS
  The protocol showed good reliability for test-retest measurements of foot placement accuracy, thus making this protocol a reliable and location-independent tool to assess performance of foot placement in elderly in assisted-living settings. In the future, measurements with elderly fallers and non-fallers should be conducted to assess validity of the protocol.
authors.affiliation: Institute of Human Movement Sciences and Sport, ETH Zurich, Switzerland. Electronic address: giuseppe.pichierri@hest.ethz.ch.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pichierri
authors.forename: Tatjana
authors.initials: T
authors.lastname: Diener
authors.forename: Kurt
authors.initials: K
authors.lastname: Murer
authors.forename: Eling D
authors.initials: ED
authors.lastname: de Bruin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D040561:Assisted Living Facilities; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000502:physiology; D015203:Reproducibility of Results
keywords: Elderly; Foot placement; Reliability; Test–retest; Video analysis