Gait variability: methods, modeling and meaning

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Gait variability: methods, modeling and meaning - Commentary

M Hausdorff

http://www.jneuroengrehab.com/content/2/1/19/abstract Journal of

NeuroEngineering and Rehabilitation 2005, 2:19 20 July 2005

Abstract

The study of gait variability, the stride-to-stride fluctuations in

walking, offers a complementary way of quantifying locomotion and its

changes with aging and disease as well as a means of monitoring the

effects of therapeutic interventions and rehabilitation. Previous

work has suggested that measures of gait variability may be more

closely related to falls, a serious consequence of many gait

disorders, than are measures based on the mean values of other

walking parameters. The July JNER series presents nine reports on the

results of recent investigations into gait variability. One novel

method for collecting unconstrained, ambulatory data is reviewed, and

a primer on analysis methods is presented along with a heuristic

approach to summarizing variability measures. In addition, the first

studies of gait variability in animal models of neurodegenerative

disease are described, as is a mathematical model of human walking

that characterizes certain complex (multifractal) features of the

motor control's pattern generator. Another investigation demonstrates

that, whereas both healthy older controls and patients with a higher-

level gait disorder walk more slowly in reduced lighting, only the

latter's stride variability increases. Studies of the effects of dual

tasks suggest that the regulation of the stride-to-stride

fluctuations in stride width and stride time may be influenced by

attention loading and may require cognitive input. Finally, a report

of gait variability in over 500 subjects, probably the largest study

of this kind, suggests how step width variability may relate to fall

risk. Together, these studies provide new insights into the factors

that regulate the stride-to-stride fluctuations in walking and pave

the way for expanded research into the control of gait and the

practical application of measures of gait variability in the clinical

setting.