title: Quantification of postural control deficits in patients with recent concussion: An inertial-sensor based approach.
abstract: BACKGROUND
  The aim of this study was to quantify postural control ability in a group with concussion compared with a healthy control group.
  
  
  METHODS
  Fifteen concussion patients (4 females, 11 males) and a group of fifteen age- and sex-matched controls were recruited. Participants were tested during the performance of the three stance variants (bilateral, tandem and unilateral) of the balance error scoring system standing on a force place, while wearing an inertial measurement unit placed at the posterior aspect of the sacrum.
  
  
  RESULTS
  The area of postural sway was computed using the force-plate and the '95% ellipsoid volume of sway' was computed from the accelerometer data. Concussed patients exhibited increased sway area (1513mm2[95% CI: 935 to 2091mm2] vs 646mm2[95% CI: 519 to 772mm2]; p=0.02) and sway volume (9.46m3s-6[95% CI: 8.02 to 19.94m3s-6] vs 2.68m3s-6[95% CI: 1.81 to 3.55m3s-6]; p=0.01) in the bilateral stance position of the balance error scoring system. The sway volume metric also had excellent accuracy in identifying task 'errors' (tandem stance: 91% accuracy [95% CI: 85-96%], p<0.001; unilateral stance: 91% accuracy [95% CI: 86-96%], p<0.001).
  
  
  CONCLUSIONS
  Individuals with concussion display increased postural sway during bilateral stance. The sway volume that was calculated from the accelerometer data not only differentiated a group with concussion from a healthy control group, but successfully identified when task errors had occurred. This may be of value in the development of a pitch-side assessment system for concussion.
authors.affiliation: Insight Centre for Data Analytics, University College Dublin, Dublin, Ireland. Electronic address: Cailbhe.doherty@insight-centre.org.
authors.forename: Cailbhe
authors.initials: C
authors.lastname: Doherty
authors.affiliation: Insight Centre for Data Analytics, University College Dublin, Dublin, Ireland. Electronic address: liang.zhao@insight-centre.org.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: St. Vincent's University Hospital, Dublin, Ireland.
authors.forename: John
authors.initials: J
authors.lastname: Ryan
authors.affiliation: Fujitsu Laboratories Ltd., Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Komaba
authors.affiliation: Fujitsu Laboratories Ltd., Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Inomata
authors.affiliation: Insight Centre for Data Analytics, University College Dublin, Dublin, Ireland.
authors.forename: Brian
authors.initials: B
authors.lastname: Caulfield
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D001924:Brain Concussion / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D020233:Gait Disorders, Neurologic / Q000503:physiopathology*; D006801:Humans; D008297:Male; D004856:Postural Balance / Q000502:physiology*; D055815:Young Adult
keywords: Biomechanics [MeSH]; Brain concussion [MeSH]; Kinetics [MeSH]; Postural balance [MeSH]