title: Analysis of medial deviation of center of pressure after initial heel contact in forefoot varus.
abstract: OBJECTIVE
  After initial heel contact, the rearfoot everts and causes medial deviation of the center of pressure (CoP). Although rearfoot angle in single-limb stance has been associated with forefoot varus (FV) ≥ 8°, medial CoP deviation has not.
  
  
  METHODS
  After 12 participants with FV < 8° (neutral group) and 11 participants with FV ≥ 8° (FV group) stepped one heel initially onto an array of pressure sensors parallel to its Y coordinate axis, when the CoP of array deviated most medially, the X coordinate of the CoP of each row was calculated to find the most medial CoP of the row. Starting since the row with the most medial CoP just began to have the same sensors with pressures >0 kPa as when it had the most medial CoP, the medial deviations of the CoP of the array, the most medial CoP of the row, and its relative position in the row (CoP%), were compared between neutral and FV groups.
  
  
  RESULTS
  The medial deviations of the most medial CoP of the row (1.1 ± 0.6 vs. 1.6 ± 0.3 mm, p = 0.049) and CoP% (2.9 ± 1.4 vs. 4.2 ± 1.1%, p = 0.023) were significantly different between neutral and FV groups, whereas that of the CoP of the array (1.1 ± 0.6 vs. 1.4 ± 0.6 mm, p = 0.36) was not.
  
  
  CONCLUSIONS
  The most medial CoP of the row and CoP% detected increased medial CoP deviation in FV ≥ 8°, and may be applied to other clinical conditions where rearfoot angle and CoP of the array after initial heel contact cannot detect significant differences.
authors.affiliation: Department of Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: wlh1@ntu.edu.tw.
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Hsi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D001835:Body Weight; D002648:Child; D005260:Female; D005528:Foot / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006365:Heel; D006801:Humans; D008297:Male; D008875:Middle Aged; D011312:Pressure; D016138:Walking / Q000502:physiology*; D055815:Young Adult
keywords: biomechanical phenomena; foot; heel; weight-bearing