title: Walking smoothness is associated with self-reported function after accounting for gait speed.
abstract: BACKGROUND
  Gait speed has shown to be an indicator of functional status in older adults; however, there may be aspects of physical function not represented by speed but by the quality of movement. The purpose of this study was to determine the relations between walking smoothness, an indicator of the quality of movement based on trunk accelerations, and physical function.
  
  
  METHODS
  Thirty older adults (mean age, 77.7±5.1 years) participated. Usual gait speed was measured using an instrumented walkway. Walking smoothness was quantified by harmonic ratios derived from anteroposterior, vertical, and mediolateral trunk accelerations recorded during overground walking. Self-reported physical function was recorded using the function subscales of the Late-Life Function and Disability Instrument.
  
  
  RESULTS
  Anteroposterior smoothness was positively associated with all function components of the Late-Life Function and Disability Instrument, whereas mediolateral smoothness exhibited negative associations. Adjusting for gait speed, anteroposterior smoothness remained associated with the overall and lower extremity function subscales, whereas mediolateral smoothness remained associated with only the advanced lower extremity subscale.
  
  
  CONCLUSIONS
  These findings indicate that walking smoothness, particularly the smoothness of forward progression, represents aspects of the motor control of walking important for physical function not represented by gait speed alone.
authors.affiliation: PT, 3471 Fifth Avenue, Suite 500, Kaufmann Building, Pittsburgh, PA 15213. kal121@pitt.edu.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Lowry
authors.forename: Jessie M
authors.initials: JM
authors.lastname: Vanswearingen
authors.forename: Subashan
authors.initials: S
authors.lastname: Perera
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Studenski
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Brach
mesh_terms: D000054:Acceleration; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D016138:Walking / Q000502:physiology*
keywords: Gait; Motor control; Physical function.