title: Segmental torso masses in adolescent idiopathic scoliosis.
abstract: BACKGROUND
  Adolescent idiopathic scoliosis is the most common type of spinal deformity whose aetiology remains unclear. Studies suggest that gravitational forces in the standing position play an important role in scoliosis progression, therefore anthropometric data is required to develop biomechanical models of the deformity. Few studies have analysed the trunk by vertebral level and none have performed investigations of the scoliotic trunk. The aim of this study was to determine the centroid, thickness, volume and estimated mass, for sections of the scoliotic trunk.
  
  
  METHODS
  Existing low-dose CT scans were used to estimate vertebral level-by-level torso masses for 20 female adolescent idiopathic scoliosis patients. ImageJ processing software was used to analyse the CT images and enable estimation of the segmental torso mass corresponding to each vertebral level.
  
  
  RESULTS
  The patients' mean age was 15.0 (SD 2.7) years with mean major Cobb angle of 52 (SD 5.9)° and mean patient weight of 58.2 (SD 11.6) kg. The magnitude of torso segment mass corresponding to each vertebral level increased by 150% from 0.6kg at T1 to 1.5kg at L5. Similarly, segmental thickness from T1-L5 increased inferiorly from a mean 18.5 (SD 2.2) mm at T1 to 32.8 (SD 3.4) mm at L5. The mean total trunk mass, as a percentage of total body mass, was 27.8 (SD 0.5) % which was close to values reported in previous literature.
  
  
  CONCLUSIONS
  This study provides new anthropometric reference data on segmental (vertebral level-by-level) torso mass in adolescent idiopathic scoliosis patients, useful for biomechanical models of scoliosis progression and treatment.
authors: QUT/Mater Paediatric Spine Research Group, Queensland University of Technology, Mater Research, Brisbane, QLD, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia. Electronic address: bethany.keenan@qut.edu.au.
authors: Bethany E
authors: BE
authors: Keenan
authors: QUT/Mater Paediatric Spine Research Group, Queensland University of Technology, Mater Research, Brisbane, QLD, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Maree T
authors: MT
authors: Izatt
authors: QUT/Mater Paediatric Spine Research Group, Queensland University of Technology, Mater Research, Brisbane, QLD, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Geoffrey N
authors: GN
authors: Askin
authors: QUT/Mater Paediatric Spine Research Group, Queensland University of Technology, Mater Research, Brisbane, QLD, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Robert D
authors: RD
authors: Labrom
authors: Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Graeme J
authors: GJ
authors: Pettet
authors: QUT/Mater Paediatric Spine Research Group, Queensland University of Technology, Mater Research, Brisbane, QLD, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Mark J
authors: MJ
authors: Pearcy
authors: QUT/Mater Paediatric Spine Research Group, Queensland University of Technology, Mater Research, Brisbane, QLD, Australia; Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors: Clayton J
authors: CJ
authors: Adam
mesh_terms: D000293:Adolescent; D000465:Algorithms; D000886:Anthropometry; D001696:Biomechanical Phenomena; D001835:Body Weight; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D015588:Observer Variation; D011187:Posture; D012016:Reference Values; D012044:Regression Analysis; D012600:Scoliosis / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D012984:Software; D014057:Tomography, X-Ray Computed; D060726:Torso; D055815:Young Adult
keywords: Adolescent idiopathic scoliosis; Anthropometric data; Anthropometry; Body segment parameters; Computed Tomography; Scoliosis progression; Torso segment masses