title: Gait adaptations in response to perturbations in adults with Down syndrome.
abstract: OBJECTIVE
  Ligamentous laxity, hypotonia and physiologic changes associated with aging lead to gait adaptations to increase control during comfortable unperturbed walking in adults with Down syndrome (DS). These changes appear at earlier ages than changes associated with aging in adults with typical development (TD) [1]. Here we describe gait adaptation and stability when gait is perturbed in relatively older adults with DS compared to their peers with TD.
  
  
  METHODS
  A volunteer sample of 14 adults with DS and 14 adults with TD, all 35-65 years of age, participated.
  
  
  METHODS
  We used 3D motion analysis to capture walking patterns at self-selected pace and in seven environmentally relevant perturbation conditions. We tested for group differences in gait parameters and amount of variability by condition: specifically percent stance, step width and stride length, velocity and frequency. To quantify overall change in gait parameters and variability from baseline to each condition, we created summative parameters of the overall percent change from baseline to each condition for each dependent variable.
  
  
  RESULTS
  Adults with DS and TD made small but complex adjustments in gait parameters and variability in response to perturbations.
  
  
  CONCLUSIONS
  Overall adults in both groups maintained group differences in gait patterns while adapting well to anticipated perturbations.
authors.affiliation: Balance Disorders Laboratory, Department of Neurology, Oregon Health and Science University, Portland, OR 97006, United States. smitbeth@ohsu.edu
authors.forename: Beth A
authors.initials: BA
authors.lastname: Smith
authors.forename: James A
authors.initials: JA
authors.lastname: Ashton-Miller
authors.forename: Beverly D
authors.initials: BD
authors.lastname: Ulrich
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000886:Anthropometry; D004314:Down Syndrome / Q000503:physiopathology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology
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