title: The effects of a concurrent task on walking in persons with transfemoral amputation compared to persons without limb loss.
abstract: BACKGROUND
  Many people with lower limb loss report the need to concentrate on walking. This may indicate increased reliance on cognitive resources when walking compared to individuals without limb loss.
  
  
  OBJECTIVE
  This study quantified changes in walking associated with addition of a concurrent cognitive task in persons with transfemoral amputation using microprocessor knees compared to age- and sex-matched controls.
  
  
  METHODS
  Observational, cross-sectional study.
  
  
  METHODS
  Quantitative motion analysis was used to assess walking under both single-task (walking alone) and dual-task (walking while performing a cognitive task) conditions. Primary outcomes were walking speed, step width, step time asymmetry, and cognitive task response latency and accuracy. Repeated-measures analysis of variance was used to examine the effects of task (single-task and dual-task) and group (transfemoral amputation and control) for each outcome.
  
  
  RESULTS
  No significant interactions between task and group were observed (all p > 0.11) indicating that a cognitive task did not differentially affect walking between groups. However, walking was slower with wider steps and more asymmetry in people with transfemoral amputation compared to controls under both conditions.
  
  
  CONCLUSIONS
  Although there were significant differences in walking between people with transfemoral amputation and matched controls, the effects of a concurrent cognitive task on walking were similar between groups.
  
  
  CONCLUSIONS
  The addition of a concurrent task did not differentially affect walking outcomes in people with and without transfemoral amputation. However, compared to people without limb loss, people with transfemoral amputation adopted a conservative walking strategy. This strategy may reduce the need to concentrate on walking but also contributed to notable gait deviations.
authors.affiliation: University of Washington, Seattle, WA, USA sjmorgan@uw.edu.
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Morgan
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Hafner
authors.affiliation: University of Washington, Seattle, WA, USA.
authors.forename: Valerie E
authors.initials: VE
authors.lastname: Kelly
mesh_terms: D000328:Adult; D000368:Aged; D000671:Amputation, Surgical; D001186:Artificial Limbs; D001288:Attention; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur; D006801:Humans; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology*
keywords: Motion analysis; amputation; artificial limb; dual-task; gait; walking