title: Describing the medial longitudinal arch using footprint indices and a clinical grading system.
abstract: BACKGROUND
  The current literature is not clear regarding the best method of determining medial longitudinal arch (MLA) height. Differences in MLA height can significantly alter lower extremity biomechanics; therefore, an accurate and reproducible assessment of arch height is essential for clinical evaluation and future research. The goal of this project was to determine the reliability of common arch height measurement techniques.
  
  
  METHODS
  Foot length, truncated foot length, navicular height, dorsal height, and footprint indices were obtained from healthy volunteers using a mirrored foot photograph box (MFPB). Between-rater and between-day reliability was determined using the interclass correlation coefficient, and the Pearson correlation coefficient was used to determine if any of the footprint parameters correlated with navicular height or normalized navicular height.
  
  
  RESULTS
  The most reliable footprint measurement was the footprint index, followed by the Staheli index, Chippaux-Smirak Index, arch index, truncated arch index, and arch length index. The correlation of footprint measurements to normalized navicular height ranged from 0.585 to 0.648.
  
  
  CONCLUSIONS
  Historically, the height of the navicular is considered to be the best approximation of MLA height. The results of this study indicate that the footprint indices are highly correlated with navicular height, indicating that both navicular height measurements and footprint measurements are valid measures of MLA height. Multiple methods exist for measuring the height of the MLA; therefore, it is important to develop a standard set of measurements to be used when foot type is used as a variable in research studies or when making a clinical diagnosis.
authors.affiliation: 102 Finch Yeager Building, DUMC 3435, Durham, NC 27710, USA. robin.queen@duke.edu
authors.forename: Robin M
authors.initials: RM
authors.lastname: Queen
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Mall
authors.forename: W Mack
authors.initials: WM
authors.lastname: Hardaker
authors.forename: James A
authors.initials: JA
authors.lastname: Nunley
mesh_terms: D000328:Adult; D000886:Anthropometry / Q000379:methods*; D003878:Dermatoglyphics; D005260:Female; D005528:Foot / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D012016:Reference Values; D015203:Reproducibility of Results; D013639:Tarsal Bones / Q000033:anatomy & histology*