title: The repeatability of gait speed and physiological cost index measurements in working adults.
abstract: OBJECTIVE
  To determine the performance characteristics of gait speed measurements and the physiological cost index (PCI; heart rate change/gait speed) in working adults.
  
  
  METHODS
  Gait speeds, heart rate changes, and non-steady state PCIs were calculated in 61 volunteers who worked in our health sciences center. These subjects completed 9 separate 100-foot walk tests in 3 separate sessions.
  
  
  RESULTS
  The mean heart rate change after a 100-foot walk was 16.6 ± 8.1 beats per minute. The mean gait speed was 76.1 ± 9.6 meters per minute, and the mean PCI was 0.22 ± 0.11 beats per meter. There were highly significant correlations among all measurements on the 9 separate tests (correlation coefficients 0.41-0.95); gait speed measurements had the highest correlations (0.91-0.95). In a multivariable model hypertension and arthritis were associated with reduced gait speeds.
  
  
  CONCLUSIONS
  Gait speed, heart rate changes, and non-steady state PCIs have good repeatability when measured over short walks. This information provides a rapid physiological assessment and a method for measuring changes in functional status in healthy subjects and most patients.
authors: Northwestern University, Chicago, IL, USA.
authors: Rishi
authors: R
authors: Raj
authors: Hoda
authors: H
authors: Mojazi Amiri
authors: Helen
authors: H
authors: Wang
authors: Kenneth M
authors: KM
authors: Nugent
mesh_terms: D000328:Adult; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005684:Gait; D006305:Health Status Indicators; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015203:Reproducibility of Results; D016138:Walking / Q000502:physiology*
keywords: functional capacity; gait speed; heart rate; physiologic cost index