title: Sagittal skin contour of the cervical spine: interexaminer and intraexaminer reliability of the flexicurve instrument.
abstract: OBJECTIVE
  To evaluate reliability of a simple instrument, the flexicurve, in determining cervical sagittal skin contour.
  
  
  METHODS
  This study obtained repeated random measurements involving 3 investigators and 30 subjects once per day over a 2-day trial period. Thirty normal subjects were examined for cervical spine skin contour twice by 3 separate investigators with a 1-day delay. With subjects in a neutral standing position, investigators placed the flexicurve on the posterior portion of the subject's neck from the external occipital protuberance to the vertebral prominens and traced the flexicurve shape onto paper. The tracings were divided into 6 equal arcs and digitized. Statistical computation was performed on the depth at 5 points, arc angle, and arc radius of curvature. Interexaminer and intraexaminer correlation coefficients (ICCs) were calculated to determine reliability.
  
  
  RESULTS
  All interexaminer correlation coefficients were in the poor range (<0.40). For the arc radius, arc angle, depth at top one third, and depth at bottom two thirds, the intraexaminer correlation coefficients were in the poor range. For the 3 deepest depths, the intraexaminer correlation coefficients were in the fair range (0.4-0.50).
  
  
  CONCLUSIONS
  The flexicurve showed marginal reliability with most (12/16) ICCs in the poor range (ICC <0.40) and 4 values in the fair range (0.4 < ICC < 0.5).
authors.affiliation: CBP Nonprofit, Inc, Elko, Nev, USA. drdeed@idealspine.com
authors.forename: Deed E
authors.initials: DE
authors.lastname: Harrison
authors.forename: Jason W
authors.initials: JW
authors.lastname: Haas
authors.forename: Donald D
authors.initials: DD
authors.lastname: Harrison
authors.forename: Burt
authors.initials: B
authors.lastname: Holland
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Janik
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000033:anatomy & histology*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D010808:Physical Examination / Q000295:instrumentation*; D015203:Reproducibility of Results; D012867:Skin / Q000033:anatomy & histology*