title: The intra- and inter-rater reliability of the tragus wall distance (TWD) measurement in non-pathological participants ages 18-34.
abstract: OBJECTIVE
  To assess intra-rater and inter-rater reliability of the tragus wall distance (TWD) measurement in non-pathologic individuals aged 18-34.
  
  
  BACKGROUND
  Physical therapists evaluate posture as a component of health status. A literature review suggests need for reliable clinical tools to assess head position.
  
  
  METHODS
  The TWD measurement is the horizontal distance between the tragus, the auricular cartilaginous flap anterior to the external auditory meatus, and a wall. Sixty-three adults aged 18-34 years were consecutively assigned to three raters for double-blinded repeated measures of TWD distance. Statistical analyses included descriptive statistics of the sample, interclass correlation coefficient (ICC), analysis of variance (ANOVA), t-tests (p < 0.05), and Pearson correlation coefficients to quantify correlations between raters and repeated measures.
  
  
  RESULTS
  ANOVA results for intra-rater reliability indicated consistency among individual raters. All raters demonstrated significant correlations across repeated measures, ICC = 0.92-0.94. ANOVA and t-test results did not support inter-rater reliability. However, ICC = 0.90, standard error of measurement = 0.22, and Pearson R = 0.84 supported inter-rater reliability. The evidence suggests that although the absolute TWD measurement values may not be reliable among raters, relative change between TWD measures demonstrates high inter-rater reliability.
  
  
  CONCLUSIONS
  TWD measurement has high intra-rater reliability. TWD measurement of a single patient by multiple raters is not supported.
authors.affiliation: Graduate School of Physical Therapy, Slippery Rock University, Slippery Rock, PA, USA. nancy.shipe@sru.edu
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Shipe
authors.forename: Barbara
authors.initials: B
authors.lastname: Billek-Sawhney
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Canter
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Meals
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Nestler
authors.forename: Janel L
authors.initials: JL
authors.lastname: Stumpff
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D010808:Physical Examination / Q000295:instrumentation / Q000379:methods*; D011187:Posture; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D055815:Young Adult