|
a |
|
b/README.md |
|
|
1 |
<h1>Long-term Recordings of Gait Dynamics</h1> |
|
|
2 |
|
|
|
3 |
<p><strong>Author:</strong> Jeffrey Hausdorff</p> |
|
|
4 |
<p><strong>Published:</strong> Aug. 16, 2001. Version: 1.0.0</p> |
|
|
5 |
|
|
|
6 |
<h2>Citation</h2> |
|
|
7 |
<p> |
|
|
8 |
Please include the standard citation for PhysioNet:<br> |
|
|
9 |
Goldberger, A., Amaral, L., Glass, L., Hausdorff, J., Ivanov, P. C., Mark, R., ... & Stanley, H. E. (2000). |
|
|
10 |
<em>PhysioBank, PhysioToolkit, and PhysioNet: Components of a new research resource for complex physiologic signals.</em> |
|
|
11 |
Circulation [Online]. 101 (23), pp. e215–e220. |
|
|
12 |
</p> |
|
|
13 |
|
|
|
14 |
<h2>Unconstrained and Metronomic Walking</h2> |
|
|
15 |
<p> |
|
|
16 |
Fractal dynamics were recently detected in the apparently “noisy” variations in the stride interval of human walking. |
|
|
17 |
Dynamical analysis of these step-to-step fluctuations revealed a self-similar pattern: fluctuations at one time scale |
|
|
18 |
are statistically similar to those at multiple other time scales, at least over hundreds of steps, while healthy |
|
|
19 |
subjects walk at their normal rate. |
|
|
20 |
</p> |
|
|
21 |
|
|
|
22 |
<p> |
|
|
23 |
To study the stability of this fractal property, we analyzed data obtained from ten healthy subjects who walked for |
|
|
24 |
1 hour at their usual, slow and fast paces. The stride interval fluctuations exhibited long-range correlations with |
|
|
25 |
power-law decay for up to a thousand strides at all three walking rates. In contrast, during metronomically-paced |
|
|
26 |
walking, these long-range correlations disappeared; variations in the stride interval were anti-correlated. The |
|
|
27 |
long-range correlations observed during spontaneous walking were not affected by removal of drifts in the time series. |
|
|
28 |
Thus, the fractal dynamics of spontaneous stride interval are normally quite robust and intrinsic to the locomotor system. |
|
|
29 |
Furthermore, this fractal property of neural output may be related to the higher nervous centers responsible for control |
|
|
30 |
of walking rhythm. |
|
|
31 |
</p> |
|
|
32 |
|
|
|
33 |
<p> |
|
|
34 |
Stride interval fluctuations were studied in ten young, healthy men. Participants had no history of any neuromuscular, |
|
|
35 |
respiratory or cardiovascular disorders, and were taking no medications. Mean age was 21.7 years (range: 18–29 years). |
|
|
36 |
Height was 1.77 ± 0.08 meters (mean ± S.D.) and weight was 71.8 ± 10.7 kg. All subjects provided informed written consent. |
|
|
37 |
</p> |
|
|
38 |
|
|
|
39 |
<p> |
|
|
40 |
Subjects walked continuously on level ground around an obstacle-free, long (either 225 or 400 meters), approximately oval |
|
|
41 |
path and the stride interval was measured using ultra-thin, force-sensitive switches taped inside one shoe. For more |
|
|
42 |
details, please see the accompanying publication. |
|
|
43 |
</p> |
|
|
44 |
|
|
|
45 |
<p> |
|
|
46 |
Each subject was given an arbitrary ID (<code>si01</code>, <code>si02</code>, ... <code>si10</code>). For each subject, there are six data files: |
|
|
47 |
</p> |
|
|
48 |
<ul> |
|
|
49 |
<li><code>.norm</code> – normal walking for 1 hour</li> |
|
|
50 |
<li><code>.slow</code> – slow walking for 1 hour</li> |
|
|
51 |
<li><code>.fast</code> – fast walking for 1 hour</li> |
|
|
52 |
<li><code>.metnrm</code> – metronomic walking at normal pace</li> |
|
|
53 |
<li><code>.metslw</code> – metronomic walking at slow pace</li> |
|
|
54 |
<li><code>.metfst</code> – metronomic walking at fast pace</li> |
|
|
55 |
</ul> |
|
|
56 |
|
|
|
57 |
<p> |
|
|
58 |
We find robust long-range correlations during unconstrained walking at all three walking rates and anti-correlations |
|
|
59 |
during metronomic walking. What do you find? Are there other rate or condition dependent effects on the histogram or |
|
|
60 |
the dynamics? |
|
|
61 |
</p> |
|
|
62 |
|
|
|
63 |
<h2>Contact</h2> |
|
|
64 |
<p> |
|
|
65 |
Hausdorff JM et al. <em>Fractal dynamics of human gait: stability of long-range correlations in stride interval fluctuations.</em> |
|
|
66 |
J Appl Physiol 80:1448–1457, 1996.<br> |
|
|
67 |
Or contact Jeff Hausdorff. |
|
|
68 |
</p> |