title: Intra-individual gait speed variability in healthy children aged 1-15 years.
abstract: BACKGROUND
  Gait speed is one of the most commonly and frequently used parameters to evaluate gait development. It is characterized by high variability when comparing different steps in children. The objective of this study was to determine intra-individual gait speed variability in children.
  
  
  METHODS
  Gait speed measurements (6-10 trials across a 3m walkway) were performed and analyzed in 8263 children, aged 1-15 years. The coefficient of variation (CV) served as a measure for intra-individual gait speed variability measured in 6.6±1.0 trials per child. Multiple linear regression analysis was conducted to evaluate the influence of age and body height on changes in variability. Additionally, a subgroup analysis for height within the group of 6-year-old children was applied.
  
  
  RESULTS
  A successive reduction in gait speed variability (CV) was observed for age groups (age: 1-15 years) and body height groups (height: 0.70-1.90 m). The CV in the oldest subjects was only one third of the CV (CV 6.25±3.52%) in the youngest subjects (CV 16.58±10.01%). Up to the age of 8 years (or 1.40 m height) there was a significant reduction in CV over time, compared to a leveling off for the older (taller) children.
  
  
  CONCLUSIONS
  The straightforward approach measuring gait speed variability in repeated trials might serve as a fundamental indicator for gait development in children. Walking velocity seems to increase to age 8. Enhanced gait speed consistency of repeated trials develops up to age 15.
authors.affiliation: University Outpatient Clinic, Sports Medicine & Sports Orthopaedics, University of Potsdam, Germany. Electronic address: thormei@uni-potsdam.de.
authors.forename: Juliane
authors.initials: J
authors.lastname: Müller
authors.forename: Steffen
authors.initials: S
authors.lastname: Müller
authors.forename: Heiner
authors.initials: H
authors.lastname: Baur
authors.forename: Frank
authors.initials: F
authors.lastname: Mayer
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001827:Body Height; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D009048:Motor Skills / Q000502:physiology*
keywords: Children; Development; Gait; Speed; Variability