title: Classification of frontal plane rearfoot motion patterns during the stance phase of walking.
abstract: BACKGROUND
  Classification of rearfoot motion patterns would assist in understanding normal rearfoot motion and would facilitate the identification of abnormal motion. We sought to identify common frontal plane rearfoot motion patterns in an asymptomatic population.
  
  
  METHODS
  Frontal plane rearfoot motion was measured with an electromagnetic motion analysis system in 279 asymptomatic individuals during barefoot walking. The coefficient of multiple correlation and visual observation were used to identify similar patterns of rearfoot motion.
  
  
  RESULTS
  Four distinct rearfoot motion patterns were identified: pattern 1 consisted of 176 individuals (63.1%) and was labeled "typical" eversion, pattern 2 consisted of 87 individuals (31.2%) and was labeled "prolonged eversion," pattern 3 consisted of nine individuals (3.2%) and was labeled "delayed eversion," and pattern 4 consisted of seven individuals (2.5%) and was labeled "early eversion."
  
  
  CONCLUSIONS
  Asymptomatic frontal plane rearfoot motion can be classified into four distinct patterns, but most individuals (94.3%) exhibit one of two motion patterns (typical or prolonged eversion).
authors.affiliation: Department of Physical Therapy, Northern Arizona University, Flagstaff, AZ 86011, USA. mark.cornwall@nau.edu
authors.forename: Mark W
authors.initials: MW
authors.lastname: Cornwall
authors.forename: Thomas G
authors.initials: TG
authors.lastname: McPoil
mesh_terms: D000293:Adolescent; D000328:Adult; D055590:Electromagnetic Phenomena; D005260:Female; D006365:Heel / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D016138:Walking / Q000502:physiology*; D055815:Young Adult