title: Use of Nintendo Wii Balance Board for posturographic analysis of Multiple Sclerosis patients with minimal balance impairment.
abstract: The Wii Balance Board (WBB) has been proposed as an inexpensive alternative to laboratory-grade Force Plates (FP) for the instrumented assessment of balance. Previous studies have reported a good validity and reliability of the WBB for estimating the path length of the Center of Pressure. Here we extend this analysis to 18 balance related features extracted from healthy subjects (HS) and individuals affected by Multiple Sclerosis (MS) with minimal balance impairment.
  
  
  
  Eighteen MS patients with minimal balance impairment (Berg Balance Scale 53.3 ± 3.1) and 18 age-matched HS were recruited in this study. All subjects underwent instrumented balance tests on the FP and WBB consisting of quiet standing with the eyes open and closed. Linear correlation analysis and Bland-Altman plots were used to assess relations between path lengths estimated using the WBB and the FP. 18 features were extracted from the instrumented balance tests. Statistical analysis was used to assess significant differences between the features estimated using the WBB and the FP and between HS and MS. The Spearman correlation coefficient was used to evaluate the validity and the Intraclass Correlation Coefficient was used to assess the reliability of WBB measures with respect to the FP. Classifiers based on Support Vector Machines trained on the FP and WBB features were used to assess the ability of both devices to discriminate between HS and MS.
  
  
  
  We found a significant linear relation between the path lengths calculated from the WBB and the FP indicating an overestimation of these parameters in the WBB. We observed significant differences in the path lengths between FP and WBB in most conditions. However, significant differences were not found for the majority of the other features. We observed the same significant differences between the HS and MS populations across the two measurement systems. Validity and reliability were moderate-to-high for all the analyzed features. Both the FP and WBB trained classifier showed similar classification performance (>80%) when discriminating between HS and MS.
  
  
  
  Our results support the observation that the WBB, although not suitable for obtaining absolute measures, could be successfully used in comparative analysis of different populations.
authors.affiliation: School of Electrical and Electronic Engineering, University College Dublin, Dublin, Ireland. giacomo.severini@ucd.ie.|Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy. giacomo.severini@ucd.ie.
authors.forename: Giacomo
authors.identifier: 0000-0002-2289-9331
authors.initials: G
authors.lastname: Severini
authors.affiliation: Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy.
authors.forename: Sofia
authors.initials: S
authors.lastname: Straudi
authors.affiliation: Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Pavarelli
authors.affiliation: Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Da Roit
authors.affiliation: Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Martinuzzi
authors.affiliation: Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Di Marco Pizzongolo
authors.affiliation: Neuroscience and Rehabilitation Department, Ferrara University Hospital, Ferrara, Italy.
authors.forename: Nino
authors.initials: N
authors.lastname: Basaglia
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000534:rehabilitation*; D009460:Neurologic Examination / Q000295:instrumentation* / Q000379:methods; D004856:Postural Balance; D015203:Reproducibility of Results; D060388:Support Vector Machine; D018910:Video Games
keywords: Multiple Sclerosis; Posturographic Analysis; Wii Balance Board