title: Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements by flexible curve.
abstract: OBJECTIVE
  The amount of postural sway and sagittal deviation of lumbar lordosis angle in measurements of standing lumbar curvature obtained by flexible curve can be decreased when using a spine stabilizer instrument. However, this assumption has not been investigated so far. This study aims to determine the effect of using a spine stabilizer instrument on the validity, reliability, and standard errors of measurement of flexible curve in the standing lumbar curvature measurements.
  
  
  METHODS
  Thirty-four volunteer men aged between 19 and 30 years participated in the study By using a 50-cm flexible curve, with and without spine stabilizer instrument, and a lumbar simple lateral radiograph (LSLR), the standing lumbar curvature was measured by three methods for each subject. These methods were called A, B and C, respectively.
  
  
  RESULTS
  By using the Pearson's correlation analysis at significance level of 0.05, the coefficient of correlation between standing lumbar curvature measurements in methods A and B with C were 0.95 and 0.84, respectively. In addition, the intraclass correlation coefficient for methods A and B were 0.94 and 0.79, respectively. Also, results of the one-way analysis of variance for comparison of pairs indicated a significant difference in the mean values of standing lumbar curvature angles between methods B and C.
  
  
  CONCLUSIONS
  Results indicated the flexible curve was an appropriate instrument for standing lumbar curvature measurements. Using spine stabilizer instrument to control postural sway increases the validity and reliability of flexible curve method and decreases its standard errors of measurement.
authors.affiliation: Department of Health and Sport Medicine, University of Tehran, Tehran, Iran.
authors.forename: Foad
authors.initials: F
authors.lastname: Seidi
authors.affiliation: Department of Health and Sport Medicine, University of Tehran, Tehran, Iran.
authors.forename: Hooman
authors.initials: H
authors.lastname: Minoonejad
authors.affiliation: Physical Therapy, Mayo Clinic, College of Medicine, Rochester, MN, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Youdas
mesh_terms: D000328:Adult; D001915:Braces; D006801:Humans; D008141:Lordosis / Q000000981:diagnostic imaging; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging*; D008161:Lumbosacral Region / Q000000981:diagnostic imaging*; D008297:Male; D011187:Posture; D011859:Radiography; D015203:Reproducibility of Results
keywords: Spine stabilizer instrument; flexible curve; postural sway; standing lumbar curvature