title: Noninvasive Optoelectronic Assessment of Induced Sagittal Imbalance Using the Vicon System.
abstract: OBJECTIVE
  Spinal diseases often induce gait disorders with multifactorial origins such as lumbar pain, radicular pain, neurologic complications, or spinal deformities. However, radiography does not permit an analysis of spinal dynamics; therefore, sagittal balance dynamics during gait remain largely unexplored. This prospective and controlled pilot study assessed the Vicon system for detecting sagittal spinopelvic imbalance, to determine the correlations between optoelectronic and radiographic parameters.
  
  
  METHODS
  Reversible anterior sagittal imbalance was induced in 24 healthy men using a thoracolumbar corset. Radiographic, optoelectronic, and comparative analyses were conducted.
  
  
  RESULTS
  Corset wearing induced significant variations in radiographic parameters indicative of imbalance; the mean C7-tilt and d/D ratio increased by 15° ± 7.4° and 359%, respectively, whereas the mean spinosacral angle decreased by 16.8° ± 8° (all P < 0.001). The Vicon system detected the imbalance; the mean spinal angle increased by 15.4° ± 5.6° (P < 0.01), the mean floor projection of the C7S1 vector (C7'S1') increased by 126.3 ± 51.9 mm (P < 0.001), and the mean C7-T10-S1 angle decreased by 9.8° ± 3° (P < 0.001). Variations in C7'S1' were significantly correlated with d/D ratio (ρ = 0.58; P < 0.05) and C7-tilt (ρ = 0.636; P < 0.05) variations.
  
  
  CONCLUSIONS
  Corset wearing induced radiographically confirmed anterior sagittal imbalance detected using the Vicon system. Optoelectronic C7'S1' correlated with radiographic C7-tilt and d/D ratio.
authors.affiliation: Department of Orthopedic Surgery, Spine Unit, Rouen University Hospital, Rouen, France; Normandie University, UNICAEN, INSERM, COMETE, Caen, France.
authors.forename: Mourad
authors.initials: M
authors.lastname: Ould-Slimane
authors.affiliation: Department of Orthopedic Surgery, Spine Unit, Rouen University Hospital, Rouen, France.
authors.forename: Charles
authors.initials: C
authors.lastname: Latrobe
authors.affiliation: Department of Radiology, Rouen University Hospital, Rouen, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Michelin
authors.affiliation: Normandie University, UNICAEN, INSERM, COMETE, Caen, France; Department of Neurophysiology, Rouen University Hospital, Rouen, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Chastan
authors.affiliation: Department of Orthopedic Surgery, Spine Unit, Rouen University Hospital, Rouen, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Dujardin
authors.affiliation: Department of Orthopedic Surgery, Spine Unit, Rouen University Hospital, Rouen, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Roussignol
authors.affiliation: Department of Orthopedic Surgery, Spine Unit, Rouen University Hospital, Rouen, France. Electronic address: gautheremi@gmail.com.
authors.forename: Rémi
authors.initials: R
authors.lastname: Gauthé
mesh_terms: D000328:Adult; D004581:Electronics / Q000379:methods*; D005684:Gait / Q000502:physiology*; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D055095:Optics and Photonics; D004856:Postural Balance / Q000502:physiology*; D013131:Spine / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D018709:Statistics, Nonparametric; D013904:Thoracic Vertebrae; D055815:Young Adult
keywords: Optoelectronic analysis; Sagittal balance; Spine; Spine disease; Vicon