title: Reliability and minimal detectable change in foot pressure measurements in typically developing children.
abstract: BACKGROUND
  In pedobarography, clinically meaningful comparison of measurements within or between subjects is limited by data variability and measurement error. This study aims to determine the components of the minimal detectable change (MDC) in impulse across all foot regions and the reliability of these measures.
  
  
  METHODS
  A convenience sample of foot pressures from 108 visits by normal, healthy subjects aged 2-17 years was studied. Each subject had three pedobarograph measurements taken per foot, with six subjects returning for a second visit for assessment of day-to-day variability. Using a five-region mask, segmental impulses were determined, and from these we obtained the coronal plane pressure index (CPPI). Inter-rater, intra-rater, and day-to-day data were analyzed using intraclass correlation coefficients (ICC) to quantify reliability. Variability of the data was analyzed to quantify the MDC.
  
  
  RESULTS
  Inter- and intra-rater reliability was high for all measurements while variability was low, indicating small direct measurement error. Generally, the largest contributing factor to the MDC was day-to-day variability. Step-to-step variability was more dependent on foot segment than age although minor age-related changes were noted. Finally, the high relative variability in the CPPI and the medial mid foot impulse resulted in very high MDCs for these measures.
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: tim.niiler@gmail.com.
authors.forename: Timothy
authors.initials: T
authors.lastname: Niiler
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: chris.church@nemours.org.
authors.forename: Chris
authors.initials: C
authors.lastname: Church
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: nancy.lennon@nemours.org.
authors.forename: Nancy
authors.initials: N
authors.lastname: Lennon
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: john.henley@nemours.org.
authors.forename: John
authors.initials: J
authors.lastname: Henley
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: ameeka.george@gmail.com.
authors.forename: Ameeka
authors.initials: A
authors.lastname: George
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: daveda.taylor@nemours.org.
authors.forename: Daveda
authors.initials: D
authors.lastname: Taylor
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: amontes@udel.edu.
authors.forename: Angelica
authors.initials: A
authors.lastname: Montes
authors.affiliation: Gait Laboratory, Nemours/Alfred I. duPont Hospital for Children, P.O. Box 269, Wilmington, DE 19899, United States. Electronic address: freeman.miller@nemours.org.
authors.forename: Freeman
authors.initials: F
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D005528:Foot / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D011312:Pressure; D015203:Reproducibility of Results; D012494:Sampling Studies; D016138:Walking / Q000502:physiology
keywords: Foot pressure; Minimal detectable change; Pedobarography; Uncertainty