title: Sagittal Thoracic and Lumbar Spine Profiles in Upright Standing and Lying Prone Positions Among Healthy Subjects: Influence of Various Biometric Features.
abstract: METHODS
  A prospective study was performed on the assessment of both thoracic and lumbar spine sagittal profiles (from C7 to S1).
  
  
  OBJECTIVE
  To propose a new noninvasive method for measuring the spine curvatures in standing and lying prone positions and to analyze their relationship with various biometric characteristics.
  
  
  BACKGROUND
  Modifications of spine curvatures (i.e. lordosis or kyphosis) are of importance in the development of spinal disorders. Studies have emphasized the development of new devices to measure the spine sagittal profiles using a noninvasive and low-cost method. To date, it has not been applied for analyzing both lumbar and thoracic alterations for various positioning.
  
  
  METHODS
  Seventy-five healthy subjects (mean 22.6 ± 4.3 yr) were recruited to participate in this study. Thoracic and lumbar sagittal profiles were assessed in standing and lying prone positions using a 3D digitizer. In addition, several biometric data were collected including maximal trunk isometric strength for flexion and extension movement. Statistical analysis consisted in data comparisons of spine profiles and a multivariate analysis including biometric features, to classify individuals considering low within- and high between-variability.
  
  
  RESULTS
  Kyphosis and lordosis angles decreased significantly from standing to lying prone position by an average of 13.4° and 16.6°, respectively. Multivariate analysis showed a sample clustering of 3 homogenous subgroups. The first group displayed larger lordosis and flexibility, and had low data values for height, weight, and strength. The second group had lower values than the overall trend of the whole sample, whereas the third group had larger score values for the torques, height, weight, waist, body mass index, and kyphosis angle but a reduced flexibility.
  
  
  CONCLUSIONS
  The present results demonstrate a significant effect of the positioning on both thoracic and lumbar spine sagittal profiles and highlight the use of cluster analysis to categorize subgroups after biometric characteristics including curvature measurement.
  
  
  METHODS
  N/A.
authors.affiliation: *Department of Osteopathic Sciences, Research Unit in Osteopathy, Faculty of Motor Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium; †Department of Rehabilitation Sciences, School of Allied Health Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA; and ‡Laboratory of Functional Anatomy, Faculty of Motor Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium.
authors.forename: Walid
authors.initials: W
authors.lastname: Salem
authors.forename: Ysaline
authors.initials: Y
authors.lastname: Coomans
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Brismée
authors.forename: Paul
authors.initials: P
authors.lastname: Klein
authors.forename: Stéphane
authors.initials: S
authors.lastname: Sobczak
authors.forename: Pierre-Michel
authors.initials: PM
authors.lastname: Dugailly
mesh_terms: D000293:Adolescent; D000328:Adult; D001699:Biometry; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D021621:Imaging, Three-Dimensional; D007537:Isometric Contraction; D007738:Kyphosis / Q000473:pathology; D008141:Lordosis / Q000473:pathology; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology; D016684:Prone Position / Q000502:physiology*; D011446:Prospective Studies; D016059:Range of Motion, Articular; D013904:Thoracic Vertebrae / Q000033:anatomy & histology* / Q000502:physiology; D019415:Torque; D060726:Torso / Q000502:physiology; D055815:Young Adult