title: Pattern description and reliability parameters of six force-time related indices measured with plantar pressure measurements.
abstract: BACKGROUND
  Functional interpretation of plantar pressure measurements is commonly done through the use of ratios and indices which are preceded by the strategic combination of a subsampling method and selection of physical quantities. However, errors which may arise throughout the determination of these temporal indices/ratio calculations (T-IRC) have not been quantified. The purpose of the current study was therefore to estimate the reliability of T-IRC following semi-automatic total mapping (SATM).
  
  
  METHODS
  Using a repeated-measures design, two experienced therapists performed three subsampling sessions on three left and right pedobarographic footprints of ten healthy participants. Following the subsampling, six T-IRC were calculated: Rearfoot-Forefoot_fti, Rearfoot-Midfoot_fti, Forefoot medial/lateral_fti, First ray_fti, Metatarsal 1-Metatarsal 5_fti, Foot medial-lateral_fti.
  
  
  RESULTS
  Patterns of the T-IRC were found to be consistent and in good agreement with corresponding knowledge from the literature. The inter-session errors of both therapists were similar in pattern and magnitude. The lowest peak inter-therapist error was found in the First ray_fti (6.5 a.u.) whereas the highest peak inter-therapist error was observed in the Forefoot medial/lateral_fti (27.0 a.u.) The magnitude of the inter-session and inter-therapist error varied over time, precluding the calculation of a simple numerical value for the error. The difference between both error parameters of all T-IRC was negligible which underscores the repeatability of the SATM protocol.
  
  
  CONCLUSIONS
  The current study reports consistent patterns for six T-IRC and similar inter-session and inter-therapist error. The proposed SATM protocol and the T-IRC may therefore serve as basis for functional interpretation of footprint data.
authors.affiliation: Department of Rehabilitation Sciences - Musculoskeletal Rehabilitation Research Group, KULeuven, Belgium; Division of Musculoskeletal Disorders, Multidisciplinary Diabetic Foot Clinic, University Hospitals Leuven, KULeuven, Belgium; Laboratory for Clinical Motion Analysis, University Hospital Pellenberg, KULeuven, Belgium; Haute Ecole Léonard De Vinci, Institut D'Enseignement Supérieur Parnasse Deux-Alice, Division of Podiatry, Bruxelles, Belgium. Electronic address: kevin.deschamps@uz.kuleuven.ac.be.
authors.forename: Kevin
authors.initials: K
authors.lastname: Deschamps
authors.forename: Philip
authors.initials: P
authors.lastname: Roosen
authors.forename: Herman
authors.initials: H
authors.lastname: Bruyninckx
authors.forename: Kaat
authors.initials: K
authors.lastname: Desloovere
authors.forename: Paul-Andre
authors.initials: PA
authors.lastname: Deleu
authors.forename: Giovanni A
authors.initials: GA
authors.lastname: Matricali
authors.forename: Louis
authors.initials: L
authors.lastname: Peeraer
authors.forename: Filip
authors.initials: F
authors.lastname: Staes
mesh_terms: D005528:Foot / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D015203:Reproducibility of Results
keywords: Footprint; Force–time related indices; Plantar pressure; Reliability