Article

Despite the widespread use of gait variability in research and
clinical studies, testing protocols designed to optimise its reliability have not
been established. This study evaluates the impact of testing protocol and
pathology on the reliability of gait variability. OBJECTIVE: To (i) estimate the
reliability of gait variability during continuous and intermittent walking
protocols in older adults and people with Parkinson's disease (PD), (ii)
determine optimal number of steps for acceptable levels of reliability of gait
variability and (iii) provide sample size estimates for use in clinical trials.
METHODS: Gait variability was measured twice, one week apart, in 27 older adults
and 25 PD participants. Participants walked at their preferred pace during: (i) a
continuous 2 min walk and (ii) 3 intermittent walks over a 12 m walkway. Gait
variability was calculated as the within-person standard deviation for step
velocity, length and width, and step, stance and swing duration. RESULTS:
Reliability of gait variability ranged from poor to excellent (intra class
correlations .041-.860; relative limits of agreement 34-89%). Gait variability
was more reliable during continuous walks. Control and PD participants
demonstrated similar reliability. Increasing the number of steps improved
reliability, with most improvement seen across the first 30 steps. CONCLUSIONS:
In this study, we identified testing protocols that improve the reliability of
measuring gait variability. We recommend using a continuous walking protocol and
to collect no fewer than 30 steps. Early PD does not appear to impact negatively
on the reliability of gait variability.
CI - Copyright (c) 2012 Elsevier B.V. All rights reserved.

Langue : ANGLAIS