title: Speed of voluntary stepping in chronic stroke survivors under single- and dual-task conditions: a case-control study.
abstract: OBJECTIVE
  To investigate voluntary step behavior of chronic stroke survivors during single- and dual-task conditions and compare the results to healthy age- and sex-matched controls.
  
  
  METHODS
  Case-control.
  
  
  METHODS
  Laboratory-based study.
  
  
  METHODS
  Chronic stroke survivors (n=16) and healthy controls (n=16).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Forward and backward rapid voluntary stepping were performed as a reaction time task under 2 conditions: (1) awaiting a cutaneous cue (single task), and (2) awaiting a cutaneous cue while performing an attention-demanding task. Step initiation, preparatory and swing phases, foot-off time, and foot-contact time were extracted from center of pressure and ground reaction forceplate data.
  
  
  RESULTS
  Chronic stroke survivors were significantly slower than healthy controls in all step parameters under single- and dual-task conditions. For dual compared with single task, the foot-contact time increased from 1295 ms to 1445 ms (12%) in chronic stroke survivors and from 876 ms to 1006 ms (15%) in controls.
  
  
  CONCLUSIONS
  The significant increase in step phase's duration during single- and dual-task conditions may be a factor contributing to the large number of falls seen in stroke patients. The interference effects of attention-demanding task were similar between groups, suggesting that both groups used similar strategies. Future research should determine whether step training can improve step decrements in chronic stroke survivors.
authors.affiliation: Schwartz Movement Analysis & Rehabilitation Laboratory, Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. itzikm@bgu.ac.il
authors.forename: Itshak
authors.initials: I
authors.lastname: Melzer
authors.forename: Irit
authors.initials: I
authors.lastname: Tzedek
authors.forename: Michal
authors.initials: M
authors.lastname: Or
authors.forename: Gali
authors.initials: G
authors.lastname: Shvarth
authors.forename: Oranit
authors.initials: O
authors.lastname: Nizri
authors.forename: Keren
authors.initials: K
authors.lastname: Ben-Shitrit
authors.forename: Lars E
authors.initials: LE
authors.lastname: Oddsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002908:Chronic Disease; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D026741:Physical Therapy Modalities; D020521:Stroke / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D016138:Walking