title: Evaluation of a visual biofeedback on the postural control in Parkinson's disease.
abstract: OBJECTIVE
  Both stabilization and orientation components of postural control are affected in Parkinson's disease (PD). These deficits are partly due to proprioceptive impairments, which frequently coexist with a visual dependence. This study aimed to evaluate if a visual biofeedback - i.e. real time anteroposterior trunk and head orientations indicated with a simplified avatar and represented in a head-mounted display - could improve the postural control of PD patients in response to a postural disturbance. The influence of focusing on one specific component of the postural control (stabilization or orientation) was also examined.
  
  
  METHODS
  Seventeen medicated PD patients performed sequences of pull-tests, either with eyes open, eyes closed or visual biofeedback, crossed with the verbal instruction to focus either on the stabilization or on the vertical body orientation. Kinematics data were collected.
  
  
  RESULTS
  Backward trunk tilts consequent to the pulls were unchanged across the different conditions. With eyes open and eyes closed, patients did not recover their initial vertical orientation by adopting a slightly tilted backward position. This bias disappeared with the visual biofeedback. Moreover, falls consecutive to the test were significantly less frequent with the visual biofeedback than in the two other visual conditions. These different orientation and stabilization parameters were not affected by the instruction.
  
  
  CONCLUSIONS
  Unlike a verbal instruction, visualizing in real time their own body's geometry improved both components of postural control of PD patients. This provides evidences in PD about links between impaired vertical orientation, deficits in balance control, and contribution of supplementary sensory cues.
authors: Université de Lorraine, faculté du sport de Nancy, DevAH-Développement, Adaptation et Handicap, EA 3450, 30, rue du Jardin-Botanique, CS 30156, 54600 Villers-lès-Nancy, France; MINATEC IDEAs Laboratory, CEA, 17, rue des Martyrs, 38054 Grenoble cedex 9, France; Laboratoire de neurosciences cognitives (LNC-UMR 7291-AMU), centre national de la recherche scientifique, centre Saint-Charles, pôle 3C, Case C, 3, place Victor-Hugo, 13331 Marseille cedex 3, France. Electronic address: sebastien.caudron@univ-lorraine.fr.
authors: S
authors: S
authors: Caudron
authors: Laboratoire de psychologie et neurocognition, UMR 5105 CNRS, université de Savoie, BP1104, 73011 Chambéry cedex, France.
authors: M
authors: M
authors: Guerraz
authors: Département de neurologie et de pathologie du mouvement, CHU Timone, AP-HM, 264, rue Saint-Pierre, 13385 Marseille cedex 5, France; Institut de neurosciences de La Timone, UMR 7289 AMU-CNRS, 27, boulevard Jean-Moulin, 13385 Marseille cedex 5, France.
authors: A
authors: A
authors: Eusebio
authors: MINATEC IDEAs Laboratory, CEA, 17, rue des Martyrs, 38054 Grenoble cedex 9, France.
authors: J-P
authors: JP
authors: Gros
authors: Département de neurologie et de pathologie du mouvement, CHU Timone, AP-HM, 264, rue Saint-Pierre, 13385 Marseille cedex 5, France; Institut de neurosciences de La Timone, UMR 7289 AMU-CNRS, 27, boulevard Jean-Moulin, 13385 Marseille cedex 5, France.
authors: J-P
authors: JP
authors: Azulay
authors: Laboratoire de neurosciences cognitives (LNC-UMR 7291-AMU), centre national de la recherche scientifique, centre Saint-Charles, pôle 3C, Case C, 3, place Victor-Hugo, 13331 Marseille cedex 3, France.
authors: M
authors: M
authors: Vaugoyeau
mesh_terms: D000368:Aged; D001676:Biofeedback, Psychology; D056228:Feedback, Sensory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology / Q000534:rehabilitation*; D004856:Postural Balance; D011434:Proprioception
keywords: Balance control; Biofeedback visuel; Centrales d’inertie; Contrôle de l’équilibre; Inertial motion sensors; Maladie de Parkinson; Orientation posturale; Parkinson's disease; Postural orientation; Sensory substitution; Suppléance sensorielle; Visual biofeedback