title: Gait characteristics associated with walking speed decline in older adults: results from the Baltimore Longitudinal Study of Aging.
abstract: BACKGROUND
  Understanding the mechanisms that contribute to walking speed decline can provide needed insight for developing targeted interventions to reduce the rate and likelihood of decline.
  
  
  OBJECTIVE
  Examine the association between gait characteristics and walking speed decline in older adults.
  
  
  METHODS
  Participants in the Baltimore Longitudinal Study of Aging aged 60 to 89 were evaluated in the gait laboratory which used a three dimensional motion capture system and force platforms to assess cadence, stride length, stride width, percent of gait cycle in double stance, anterior-posterior mechanical work expenditure (MWE), and medial-lateral MWE. Usual walking speed was assessed over 6 m at baseline and follow-up. Gait characteristics associated with meaningful decline (decline≥0.05 m/s/y) in walking speed were evaluated by logistic regression adjusted for age, sex, race, height, weight, initial walking speed and follow-up time.
  
  
  RESULTS
  Among 362 participants, the average age was 72.4 (SD=8.1) years, 51% were female, 27% were black and 23% were identified has having meaningful decline in usual walking speed with an average follow-up time of 3.2 (1.1) years. In the fully adjusted model, faster cadence [ORadj=0.65, 95% CI (0.43,0.97)] and longer strides [ORadj=0.87, 95% CI (0.83,0.91)] were associated with lower odds of decline. However age [ORadj=1.04, 95% CI (0.99,1.10)] was not associated with decline when controlling for gait characteristics and other demographics.
  
  
  CONCLUSIONS
  A sizable proportion of healthy older adults experienced walking speed decline over an average of 3 years. Longer stride and faster cadence were protective against meaningful decline in usual walking speed.
authors.affiliation: Department of Kinesiology, Towson University, Towson, MD, USA. Electronic address: gjerome@towson.edu.
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Jerome
authors.affiliation: Department of Mechanical Engineering, Chonnam National University, Yeosu, South Korea.
authors.forename: Seung-uk
authors.initials: SU
authors.lastname: Ko
authors.affiliation: Longitudinal Studies Section, National Institute on Aging (NIA/NIH), Baltimore, MD, USA.
authors.forename: Danielle
authors.initials: D
authors.lastname: Kauffman
authors.affiliation: Longitudinal Studies Section, National Institute on Aging (NIA/NIH), Baltimore, MD, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Studenski
authors.affiliation: Longitudinal Studies Section, National Institute on Aging (NIA/NIH), Baltimore, MD, USA.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.affiliation: Longitudinal Studies Section, National Institute on Aging (NIA/NIH), Baltimore, MD, USA.
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015142:Baltimore; D001827:Body Height; D001835:Body Weight; D005260:Female; D005684:Gait; D015577:Geriatric Assessment / Q000379:methods; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D016138:Walking
keywords: Aging; Cadence; Functional decline; Gait; Stride length