title: Stepping strategies used by post-stroke individuals to maintain margins of stability during walking.
abstract: BACKGROUND
  People recovering from a stroke are less stable during walking compared to able-bodied controls. The purpose of this study was to examine whether and how post-stroke individuals adapt their steady-state gait pattern to maintain or increase their margins of stability during walking, and to examine how these strategies differ from strategies employed by able-bodied people.
  
  
  METHODS
  Ten post-stroke individuals and 9 age-matched able-bodied individuals walked on the Computer Assisted Rehabilitation Environment. Medio-lateral translations of the walking surface were imposed to manipulate gait stability. To provoke gait adaptations, a gait adaptability task was used, in which subjects occasionally had to hit a virtual target with their knees. We measured medio-lateral and backward margins of stability, and the associated gait parameters walking speed, step length, step frequency, and step width.
  
  
  RESULTS
  Post-stroke participants showed similar medio-lateral margins of stability as able-bodied people in all conditions. This was accomplished by a larger step width and a relatively high step frequency. Post-stroke participants walked overall slower and decreased walking speed and step length even further in response to both manipulations compared to able-bodied participants, resulting in a tendency towards an overall smaller backward margins of stability, and a significantly smaller backward margin of stability during the gait adaptability task.
  
  
  CONCLUSIONS
  Post-stroke individuals have more difficulties regulating their walking speed, and the underlying parameters step frequency and step length, compared to able-bodied controls. These quantities are important in regulating the size of the backward margin of stability when walking in complex environments.
authors.affiliation: Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, The Netherlands.
authors.forename: Laura
authors.initials: L
authors.lastname: Hak
authors.forename: Han
authors.initials: H
authors.lastname: Houdijk
authors.forename: Peter
authors.initials: P
authors.lastname: van der Wurff
authors.forename: Maarten R
authors.initials: MR
authors.lastname: Prins
authors.forename: Agali
authors.initials: A
authors.lastname: Mert
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Beek
authors.forename: Jaap H
authors.initials: JH
authors.lastname: van Dieën
mesh_terms: D000222:Adaptation, Physiological; D001696:Biomechanical Phenomena; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology*; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000150:complications; D000071939:Stroke Rehabilitation; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology*
keywords: Gait; Margins of stability; Step frequency; Step length; Step width; Stroke; Walking speed