title: Sagittal plane coordination dynamics of typically developing gait.
abstract: BACKGROUND
  Individuals who undergo an instrumented gait analysis often have an aberrant gait pattern due to neuromuscular impairments that adversely affect their coordination. Conventional instrumented gait analysis descriptors fail to capture the complex coordination dynamics of gait. This paper presents a straightforward methodology for generating descriptors of coordination dynamics based on dynamical systems theory and provides the largest reported dataset of sagittal plane coordination measures, including adjacent and non-adjacent segment pairings, from individuals free of gait pathology walking over-ground.
  
  
  METHODS
  Tri-planar marker trajectories from 104 unimpaired subjects between the ages of 8 and 66 years were collected as they walked at a self-selected speed on a level surface. Phase portraits for the pelvis, thigh, shank, and foot and continuous relative phase diagrams for the segment pairs of pelvis-thigh, thigh-shank, shank-foot, and thigh-foot were calculated.
  
  
  RESULTS
  The low coefficients of variation for each coordination curve are comparable to inter-subject coefficients of variation for kinematic curves, narrow confidence intervals for relative phase angles at four essential footfall conditions, and small standard deviation bands of the continuous relative phase diagrams are evidence that these curves characterize the coordination dynamics of normal gait.
  
  
  CONCLUSIONS
  These findings support the use of this normative dataset as a reference for coordination studies in the clinic or research laboratory. Improving our understanding of gait strategies from the level of coordination and characterizing the natural variability in gait patterns offer a means to enhance our understanding of atypical gait patterns.
authors.affiliation: Department of Bioengineering, Mail Stop 8607, Research 2, Building P15, 12700 E 19th Avenue, Room 6C03, Aurora, CO 80045-2560, USA; Center for Gait & Movement Analysis Lab, Children's Hospital Colorado, 13123 E. 16th Ave., B476, Aurora, CO 80045, USA. Electronic address: katy.worster@ucdenver.edu.
authors.forename: Kate
authors.initials: K
authors.lastname: Worster
authors.affiliation: Center for Gait & Movement Analysis Lab, Children's Hospital Colorado, 13123 E. 16th Ave., B476, Aurora, CO 80045, USA. Electronic address: Joanne.valvano@childrenscolorado.org.
authors.forename: Joanne
authors.initials: J
authors.lastname: Valvano
authors.affiliation: Department of Bioengineering, Mail Stop 8607, Research 2, Building P15, 12700 E 19th Avenue, Room 6C03, Aurora, CO 80045-2560, USA; Center for Gait & Movement Analysis Lab, Children's Hospital Colorado, 13123 E. 16th Ave., B476, Aurora, CO 80045, USA. Electronic address: James.carollo@childrenscolorado.org.
authors.forename: James J
authors.initials: JJ
authors.lastname: Carollo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009424:Nervous System Physiological Phenomena; D012189:Retrospective Studies; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: Continuous relative phase; Coordination dynamics; Dynamical systems; Normal gait; Phase portrait