title: Do quiet standing centre of pressure measures within specific frequencies differ based on ability to recover balance in individuals with stroke?
abstract: To determine whether quiet standing measures at specific frequency levels (representative of reactive control) differed between individuals with stroke based on their ability to recover balance (Failed or Successful Responses to external perturbations).
  
  
  
  Individuals with stroke completed a clinical assessment, including 30 s of quiet standing and lean-and-release postural perturbations, at admission to in-patient rehabilitation. Quiet standing centre of pressure (COP) signals were calculated and discrete wavelet decomposition was performed. Net COP amplitude, between-limb synchronization, and ratios of individual-limb COP were determined for each frequency level of interest, and for the non-decomposed signal (all frequency levels). Outcome measures were compared between individuals who exhibited Failed and Successful Responses during (a) unconstrained and (b) encouraged-use lean-and-release trials.
  
  
  
  Individuals with Failed Responses during the unconstrained lean-and-release trials displayed greater net COP amplitude than those with Successful Responses, specifically within a frequency range of 0.40-3.20Hz.
  
  
  
  Reduced ability to recover balance among individuals with stroke may be reflected in impaired reactive control of quiet standing.
  
  
  
  These results provide insight into the mechanism by which reactive control of quiet standing is impaired in individuals with stroke, and may inform assessment and rehabilitation strategies for post-stroke reactive balance control.
authors.affiliation: Toronto Rehabilitation Institute, University Health Network, 550 University Ave, Toronto, ON M5G 2A2, Canada. Electronic address: alison.schinkel-ivy@uhn.ca.
authors.forename: Alison
authors.initials: A
authors.lastname: Schinkel-Ivy
authors.affiliation: Faculty of Kinesiology and Recreation Management, University of Manitoba, 66 Chancellors Cir, Winnipeg, MB R3T 2N2, Canada.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Singer
authors.affiliation: Toronto Rehabilitation Institute, University Health Network, 550 University Ave, Toronto, ON M5G 2A2, Canada; Department of Physical Therapy, University of Toronto, 500 University Ave, Toronto, ON M5G 1V7, Canada.
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Inness
authors.affiliation: Toronto Rehabilitation Institute, University Health Network, 550 University Ave, Toronto, ON M5G 2A2, Canada; Department of Physical Therapy, University of Toronto, 500 University Ave, Toronto, ON M5G 1V7, Canada; Evaluative Clinical Sciences, Hurvitz Brain Sciences Research Program, Sunnybrook Research Institute, 2075 Bayview Ave, Toronto, ON M4N 3M5, Canada.
authors.forename: Avril
authors.initials: A
authors.lastname: Mansfield
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D011187:Posture; D020521:Stroke / Q000175:diagnosis / Q000503:physiopathology*; D000071939:Stroke Rehabilitation
keywords: Ability to recover balance; Centre of pressure; Discrete wavelet analysis; Quiet standing; Stroke