title: The reliability of non-invasive biophysical outcome measures for evaluating normal and hyperkeratotic foot skin.
abstract: BACKGROUND
  Hyperkeratosis of foot skin is a common skin problem affecting people of different ages. The clinical presentation of this condition can range from dry flaky skin, which can lead to fissures, to hard callused skin which is often painful and debilitating. The purpose of this study was to test the reliability of certain non-invasive skin measurement devices on foot skin in normal and hyperkeratotic states, with a view to confirming their use as quantitative outcome measures in future clinical trials.
  
  
  METHODS
  Twelve healthy adult participants with a range of foot skin conditions (xerotic skin, heel fissures and plantar calluses) were recruited to the study. Measurements of normal and hyperkeratotic skin sites were taken using the following devices: Corneometer® CM 825, Cutometer® 580 MPA, Reviscometer® RVM 600, Visioline® VL 650 Quantiride® and Visioscan® VC 98, by two investigators on two consecutive days. The intra and inter rater reliability and standard error of measurement for each device was calculated.
  
  
  RESULTS
  The data revealed the majority of the devices to be reliable measurement tools for normal and hyperkeratotic foot skin (ICC values > 0.6). The surface evaluation parameters for skin: SEsc and SEsm have greater reliability compared to the SEr measure. The Cutometer® is sensitive to soft tissue movement within the probe, therefore measurement of plantar soft tissue areas should be approached with caution. Reviscometer® measures on callused skin demonstrated an unusually high degree of error.
  
  
  CONCLUSIONS
  These results confirm the intra and inter rater reliability of the Corneometer®, Cutometer®, Visioline® and Visioscan® in quantifying specific foot skin biophysical properties.
authors.affiliation: School of Health Sciences, Centre for Health Sciences Research, University of Salford, Manchester, UK.
authors.forename: Farina
authors.initials: F
authors.lastname: Hashmi
authors.affiliation: Postgraduate student, School of Health Sciences, Centre for Health Sciences Research, University of Salford, Manchester, UK.
authors.forename: Ciaran
authors.initials: C
authors.lastname: Wright
authors.affiliation: Research lead: Foot and Ankle Research Programme, Centre for Health Sciences Research, School of Health Sciences, University of Salford, Manchester, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Nester
authors.affiliation: Senior Innovation Associate, Reckitt Benckiser, Dansom Lane, Hull, UK.
authors.forename: Sharon
authors.initials: S
authors.lastname: Lam
keywords: Biomechanics; Foot; Hyperkeratosis; Physiology; Quantification; Reliability; Skin