title: Challenges to measure hydration, redness, elasticity and perfusion in the unloaded sacral region of healthy persons after supine position.
abstract: OBJECTIVE
  To combine measurement methods of biophysical skin properties in a clinical setting and to measure baseline values in the unloaded sacral region of healthy persons after lying 30 min in supine position.
  
  
  METHODS
  Hydration (Corneometer® CM 825), redness (Mexameter® MX 18), elasticity (Cutometer® MPA 580) and perfusion (PeriFlux System 5000) of the skin in the sacral region of 10 healthy participants (median age: 26.9 years) were measured consecutively in the laying position by two trained examiners.
  
  
  RESULTS
  The assessment duration for all four parameters lasted about 15 min. Intra-class correlation coefficients were overall moderate to strong (hydration r = 0.594, redness r = 0.817, elasticity r = 0.719, perfusion r = 0.591). Hydration (median 27.7 arbitrary units (AU)) mainly indicated dry skin conditions. Redness (median 158.5 AU) was low. Elasticity (median 0.880 AU) showed similar values as in the neck region. Perfusion (median 17.1 AU) showed values in the range of results reported in the literature.
  
  
  CONCLUSIONS
  Biophysical skin properties in the sacral region after supine position can be measured within periods of 15 min. The results provide baseline data for the skin of healthy persons as well as insights into skin-physiological variations. But it remains challenging to optimize measurement procedures and test protocols when transferring preclinical tests in a clinical application.
authors.affiliation: Swiss Paraplegic Centre, Nottwil, Switzerland. Electronic address: anke.scheel@paraplegie.ch.
authors.forename: Anke
authors.initials: A
authors.lastname: Scheel-Sailer
authors.affiliation: Swiss Paraplegic Centre, Nottwil, Switzerland.
authors.forename: Angela
authors.initials: A
authors.lastname: Frotzler
authors.affiliation: Swiss Paraplegic Centre, Nottwil, Switzerland.
authors.forename: Gabi
authors.initials: G
authors.lastname: Mueller
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Protection and Physiology, St. Gallen, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Annaheim
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Protection and Physiology, St. Gallen, Switzerland.
authors.forename: René Michel
authors.initials: RM
authors.lastname: Rossi
authors.affiliation: Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Protection and Physiology, St. Gallen, Switzerland.
authors.forename: Siegfried
authors.initials: S
authors.lastname: Derler
mesh_terms: D000328:Adult; D004548:Elasticity; D005260:Female; D006801:Humans; D008297:Male; D012447:Sacrum; D012879:Skin Physiological Phenomena; D016683:Supine Position
keywords: Baseline values; Biophysical skin properties; Pressure ulcer; Reliability; Skin physiology