Unconstrained and Metronomic Walking
Fractal dynamics were recently detected in the apparently “noisy” variations in the stride interval of human walking. Dynamical analysis of these step-to-step fluctuations revealed a self-similar pattern: fluctuations at one time scale are statistically similar to those at multiple other time scales, at least over hundreds of steps, while healthy subjects walk at their normal rate. To study the stability of this fractal property, we analyzed data obtained from ten healthy subjects who walked for 1 hour at their usual, slow and fast paces. The stride interval fluctuations exhibited long-range correlations with power-law decay for up to a thousand strides at all three walking rates. In contrast, during metronomically-paced walking, these long-range correlations disappeared; variations in the stride interval were anti-correlated. The long-range correlations observed during spontaneous walking were not affected by removal of drifts in the time series. Thus, the fractal dynamics of spontaneous stride interval are normally quite robust and intrinsic to the locomotor system. Furthermore, this fractal property of neural output may be related to the higher nervous centers responsible for control of walking rhythm.
Stride interval fluctuations were studied in ten young, healthy men. Participants had no history of any neuromuscular, respiratory or cardiovascular disorders, and were taking no medications. Mean age was 21.7 years (range: 18-29 years). Height was 1.77 ± 0.08 meters (mean ± S.D.) and weight was 71.8 ± 10.7 kg. All subjects provided informed written consent.
Subjects walked continuously on level ground around an obstacle free, long (either 225 or 400 meters), approximately oval path and the stride interval was measured using ultra-thin, force sensitive switches taped inside one shoe. For more details, please see the accompanying publication.
Each subject was given an arbitrary id (si01, si02, ... si10). For each subject, there are six data files: normal (.norm), slow (.slow) and fast (.fast) walking for 1 hour each as well as walking in time to a metronome at normal (.metnrm), slow (.metslw) and fast (.metfst) paces.
We find robust long-range correlations during unconstrained walking at all three walking rates and anti-correlations during metronomic walking. What do you find? Are there other rate or condition dependent effects on the histogram or the dynamics?
For more information, please see:
or contact Jeff Hausdorff.
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Parent Directory - DOI 19-Feb-2019 15:53 19 MD5SUMS 13-Jul-2005 03:27 2.8K SHA1SUMS 13-Jul-2005 03:27 3.3K SHA256SUMS 18-Sep-2007 13:40 4.9K fig.png 16-Aug-2001 15:35 37K fig.ps 16-Aug-2001 15:33 281K local.css 28-Oct-2015 20:02 3.1K si01.fast 17-Jan-2001 20:47 21K si01.metfst 17-Jan-2001 20:47 11K si01.metnrm 17-Jan-2001 20:47 9.7K si01.metslw 17-Jan-2001 20:47 8.8K si01.norm 17-Jan-2001 20:47 20K si01.slow 17-Jan-2001 20:47 19K si02.fast 17-Jan-2001 20:47 22K si02.metfst 17-Jan-2001 20:47 10K si02.metnrm 17-Jan-2001 20:47 11K si02.metslw 17-Jan-2001 20:47 10K si02.norm 17-Jan-2001 20:47 20K si02.slow 17-Jan-2001 20:47 20K si03.fast 17-Jan-2001 20:47 19K si03.metfst 17-Jan-2001 20:47 11K si03.metnrm 17-Jan-2001 20:47 9.7K si03.metslw 17-Jan-2001 20:47 8.0K si03.norm 17-Jan-2001 20:47 20K si03.slow 17-Jan-2001 20:47 21K si04.fast 17-Jan-2001 20:47 21K si04.metfst 17-Jan-2001 20:47 11K si04.metnrm 17-Jan-2001 20:47 10K si04.metslw 17-Jan-2001 20:47 8.3K si04.norm 17-Jan-2001 20:47 18K si04.slow 17-Jan-2001 20:47 15K si05.fast 17-Jan-2001 20:47 22K si05.metfst 17-Jan-2001 20:47 11K si05.metnrm 17-Jan-2001 20:47 9.3K si05.metslw 17-Jan-2001 20:47 7.7K si05.norm 17-Jan-2001 20:47 20K si05.slow 17-Jan-2001 20:47 15K si06.fast 17-Jan-2001 20:47 20K si06.metfst 17-Jan-2001 20:47 8.4K si06.metnrm 17-Jan-2001 20:47 9.6K si06.metslw 17-Jan-2001 20:47 10K si06.norm 17-Jan-2001 20:47 19K si06.slow 17-Jan-2001 20:47 17K si07.fast 17-Jan-2001 20:47 20K si07.metfst 17-Jan-2001 20:47 10K si07.metnrm 17-Jan-2001 20:47 10K si07.metslw 17-Jan-2001 20:47 8.3K si07.norm 17-Jan-2001 20:47 17K si07.slow 17-Jan-2001 20:47 16K si08.fast 17-Jan-2001 20:47 22K si08.metfst 17-Jan-2001 20:47 10K si08.metnrm 17-Jan-2001 20:47 8.4K si08.metslw 17-Jan-2001 20:47 7.1K si08.norm 17-Jan-2001 20:47 17K si08.slow 17-Jan-2001 20:47 12K si09.fast 17-Jan-2001 20:47 20K si09.metfst 17-Jan-2001 20:47 9.9K si09.metnrm 17-Jan-2001 20:47 9.2K si09.metslw 17-Jan-2001 20:47 8.3K si09.norm 17-Jan-2001 20:47 18K si09.slow 17-Jan-2001 20:47 16K si10.fast 17-Jan-2001 20:47 19K si10.metfst 17-Jan-2001 20:47 9.4K si10.metnrm 17-Jan-2001 20:47 9.0K si10.metslw 17-Jan-2001 20:47 8.1K si10.norm 17-Jan-2001 20:47 17K si10.slow 17-Jan-2001 20:47 15K
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Updated Friday, 28 October 2016 at 18:58 BRST