title: Validity of a quantitative clinical measurement tool of trunk posture in idiopathic scoliosis.
abstract: METHODS
  Concurrent validity between postural indices obtained from digital photographs (two-dimensional [2D]), surface topography imaging (three-dimensional [3D]), and radiographs.
  
  
  OBJECTIVE
  To assess the validity of a quantitative clinical postural assessment tool of the trunk based on photographs (2D) as compared to a surface topography system (3D) as well as indices calculated from radiographs.
  
  
  BACKGROUND
  To monitor progression of scoliosis or change in posture over time in young persons with idiopathic scoliosis (IS), noninvasive and nonionizing methods are recommended. In a clinical setting, posture can be quite easily assessed by calculating key postural indices from photographs.
  
  
  METHODS
  Quantitative postural indices of 70 subjects aged 10 to 20 years old with IS (Cobb angle, 15 degrees -60 degrees) were measured from photographs and from 3D trunk surface images taken in the standing position. Shoulder, scapula, trunk list, pelvis, scoliosis, and waist angles indices were calculated with specially designed software. Frontal and sagittal Cobb angles and trunk list were also calculated on radiographs. The Pearson correlation coefficients (r) was used to estimate concurrent validity of the 2D clinical postural tool of the trunk with indices extracted from the 3D system and with those obtained from radiographs.
  
  
  RESULTS
  The correlation between 2D and 3D indices was good to excellent for shoulder, pelvis, trunk list, and thoracic scoliosis (0.81>r<0.97; P<0.01) but fair to moderate for thoracic kyphosis, lumbar lordosis, and thoracolumbar or lumbar scoliosis (0.30>r<0.56; P<0.05). The correlation between 2D and radiograph spinal indices was fair to good (-0.33 to -0.80 with Cobb angles and 0.76 for trunk list; P<0.05).
  
  
  CONCLUSIONS
  This tool will facilitate clinical practice by monitoring trunk posture among persons with IS. Further, it may contribute to a reduction in the use of radiographs to monitor scoliosis progression.
authors.affiliation: Centre de recherche, CHU Sainte-Justine, Université de Montréal, Montréal, Canada. carole.fortin@umontreal.ca
authors.forename: Carole
authors.initials: C
authors.lastname: Fortin
authors.forename: Debbie E
authors.initials: DE
authors.lastname: Feldman
authors.forename: Farida
authors.initials: F
authors.lastname: Cheriet
authors.forename: Hubert
authors.initials: H
authors.lastname: Labelle
mesh_terms: D000293:Adolescent; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D010781:Photography; D011187:Posture; D011237:Predictive Value of Tests; D011792:Quebec; D011859:Radiography; D015203:Reproducibility of Results; D012600:Scoliosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D012720:Severity of Illness Index; D012984:Software; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D013997:Time Factors; D055815:Young Adult