title: Interexaminer reliability of supine leg checks for discriminating leg-length inequality.
abstract: OBJECTIVE
  The purpose of this study was to quantify interexaminer reliability of a standardized supine leg check procedure used to screen for leg-length inequality.
  
  
  METHODS
  Two doctors of chiropractic used a standardized supine leg check procedure to examine 50 volunteers for leg-length inequality. The order of examination was randomized. The side and magnitude of leg-length inequality were determined to the nearest 1/8 in. Subjects and examiners were blinded. Interexaminer reliability was assessed with a Bland-Altman plot, tolerance table of absolute differences, a quadratic weighted κ statistic for quantitative scores, and a Gwet's first-order agreement coefficient for dichotomous ratings.
  
  
  RESULTS
  The quadratic weighted κ statistic to quantify the reliability of the rating scale was 0.44 (95% confidence interval, 0.21-0.67), indicating moderate reliability. The 2 examiners agreed exactly 32% of the time, within 1/8 in 58% of the time, within 3/16 in 72% of the time, and within 3/8 in 92% of the time. The Bland-Altman plot revealed possible heterogeneity in reliability that requires additional study. The examiners agreed on the presence of a leg-length inequality of at least 1/8 in in 40 (80%) of 50 subjects (first-order agreement coefficient, 0.76), suggesting good agreement for this diagnostic category.
  
  
  CONCLUSIONS
  The examiners showed moderate reliability in assessing leg-length inequality at 1/8-in increments and good reliability in determining the presence of a leg-length inequality.
authors.affiliation: Upper Cervical Research Foundation, Raleigh, NC, USA. chuckwoodfield@yahoo.com
authors.forename: H Charles
authors.initials: HC
authors.lastname: Woodfield
authors.forename: B Burt
authors.initials: BB
authors.lastname: Gerstman
authors.forename: Renate Henry
authors.initials: RH
authors.lastname: Olaisen
authors.forename: Dale F
authors.initials: DF
authors.lastname: Johnson
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007870:Leg Length Inequality / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010808:Physical Examination / Q000379:methods* / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D016683:Supine Position; D055815:Young Adult