title: The effect of prolonged standing on touch sensitivity threshold of the foot: a pilot study.
abstract: OBJECTIVE
  To determine the effect of prolonged standing on touch sensitivity of the foot.
  
  
  METHODS
  An observational study with replications.
  
  
  METHODS
  University laboratory.
  
  
  METHODS
  Ten healthy college students (5 men and 5 women), with a mean ± SD age of 23.5 ± 4.1 years and body mass of 67.4 ± 12.6 kg.
  
  
  METHODS
  Semmes-Weinstein monofilament tests were administered to 12 locations on the dorsal and plantar surfaces of the foot before and after 4 hours of standing. These locations were formed into several groupings (toes, metatarsal heads, midfoot, heel, all plantar sites, all dorsal sites), and paired t-tests were used to test for significant changes in sensitivity threshold after standing.
  
  
  METHODS
  The difference between sensitivity thresholds measured before and after standing for different locations on the foot.
  
  
  RESULTS
  The average of all sensitivity thresholds on the plantar surface of the foot decreased (indicating increased sensitivity) from 0.56 to 0.36 g (P < .01) after 4 hours of prolonged standing. This change in threshold equated to a difference of 1 Semmes-Weinstein monofilament level. Changes in the sensitivity threshold of the dorsal aspect of the foot were not significant.
  
  
  CONCLUSIONS
  Analysis of the results suggests that the plantar foot has greater sensitivity to touch after prolonged standing. These findings may be useful for identifying potential unintended bias in clinical touch sensitivity testing. Future research is necessary to understand the underlying mechanisms for this sensitivity change and to determine the onset and recovery times for sensitivity changes.
authors.affiliation: Center for Ergonomics, Industrial and Operations Engineering, University of Michigan, Ann Arbor, MI, USA. newiggermann@gmail.com
authors.forename: Neal E
authors.initials: NE
authors.lastname: Wiggermann
authors.forename: Robert A
authors.initials: RA
authors.lastname: Werner
authors.forename: W Monroe
authors.initials: WM
authors.lastname: Keyserling
mesh_terms: D005260:Female; D005528:Foot / Q000294:innervation*; D006801:Humans; D008297:Male; D010812:Physical Stimulation / Q000379:methods; D010865:Pilot Projects; D011187:Posture / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology*; D014110:Touch; D055815:Young Adult