title: Reproducibility and validity of the Nintendo Wii Balance Board for measuring shoulder sensorimotor control in prone lying.
abstract: For the lower limbs, the Nintendo Wii Balance Board (NWBB) has been widely used to measure postural control. However, this has not been performed for upper limb measurements. Further, the NWBB has shown to produce more background noise with decreasing loads, which may be of concern when used for upper limb testing. The aim was to investigate reproducibility and validity of the NWBB.
  
  
  
  A test-retest design was performed with 68 subjects completing three different prone lying, upper limb weight-bearing balance tasks on a NWBB: two-arms, eyes closed (1) one-arm, non-dominant/non-injured (2) and one-arm, dominant/injured (3). Each task was repeated three times over the course of two test sessions with a 30-min break in between. Further, the level of background noise from a NWBB was compared with a force platform through systematic loading of both boards with increasing deadweights ranging from 5 to 90kg.
  
  
  
  Test-retest reproducibility was high with ICCs ranging from 0.95 to 0.97 (95% CI 0.92 to 0.98). However, systematic bias and tendencies for funnel effects in the Bland Altman plots for both one-armed tests were present. The concurrent validity of the NWBB was low (CCC 0.17 (95% CI 0.12-0.22)) due to large differences between the NWBB and force platform in noise sensitivity at low deadweights (especially below 50kg).
  
  
  
  The NWBB prone lying, shoulder sensorimotor control test was highly reproducible. Though, concurrent validity of the NWBB was poor compared to a force platform. Further investigation of the impact of the background noise, especially at low loads, is needed.
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. Electronic address: heshoj@health.sdu.dk.
authors.forename: H
authors.initials: H
authors.lastname: Eshoj
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; Institute of Occupational Therapy, Physiotherapy and Radiography, Department of Health Sciences, Bergen University College, Norway.
authors.forename: Birgit
authors.initials: B
authors.lastname: Juul-Kristensen
authors.affiliation: Hospital of Southern Jutland, Center for Orthopedics and Medicine, Rehabilitation Clinic, Aabenraa, Denmark.
authors.forename: Rene Gam Bender
authors.initials: RGB
authors.lastname: Jørgensen
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D016684:Prone Position; D015203:Reproducibility of Results; D012782:Shoulder / Q000502:physiology*; D034941:Upper Extremity / Q000502:physiology; D018910:Video Games; D016474:Weight-Bearing; D055815:Young Adult
keywords: Nintendo Wii Balance Board; Postural sway; Reliability; Sensorimotor control; Shoulder; Validity