title: Age-associated differences in the gait pattern changes of older adults during fast-speed and fatigue conditions: results from the Baltimore longitudinal study of ageing.
abstract: OBJECTIVE
  the present study investigated the effects of walking under different challenges and kinematics and kinetics generated during these activities and how these vary with age. We hypothesised that age-associated changes in gait speed and kinetics are more pronounced during fast-speed walking and post-activity walking, compared with usual-speed walking.
  
  
  METHODS
  investigated walking under three conditions: (i) usual speed, (ii) fast speed and (iii) post-activity in 183 Baltimore Longitudinal Study of Aging participants (mean 73 ± 9 years) who could walk unassisted.
  
  
  RESULTS
  across all tasks, gait speed decreased with older age and this decline rate was exacerbated in the fast-speed walking task, compared with usual-speed walking (P < 0.001). Medial-lateral (ML) hip-generative mechanical work expenditure declined with age and the rate of decline was steeper for walking at fast speed and post-activity during hip extension (P = 0.032 and 0.027, respectively), compared with usual-speed walking.
  
  
  CONCLUSIONS
  these findings indicate that older adults experience exacerbated declines in gait speed and ML control of the hip, which is explicitly evident during challenging walking. Exercise programmes aimed at improving gait speed and ML joint power from hip and ankle may help reverse age-associated changes in gait pattern among older adults.
authors.affiliation: National Institute on Aging, NIH, Clinical Research Branch, Baltimore, MD, USA. kos2@mail.nih.gov
authors.forename: Seung-uk
authors.initials: SU
authors.lastname: Ko
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Hausdorff
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000843:Ankle Joint / Q000502:physiology; D015142:Baltimore; D001696:Biomechanical Phenomena; D015444:Exercise / Q000502:physiology*; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D007700:Kinetics; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016138:Walking / Q000502:physiology*