The data contained here are from 50 healthy children ranging in age
from 40 months to 163 months. Each data file is named with a subject
identifier (1-50) and the subject's age (e.g., the file name 2-45.txt
indicates that subject #2 is 45 months old).  Each data file contains
two columns of data in text format. The first column is the time (in
seconds), and the second column is the stride interval (in seconds)
or the gait cycle duration, the time from heel strike to heel strike
of the same foot.

For more information, please see Hausdorff et al.,
Journal of  Applied Physiology, vol.  86: 1040-1047, 1999 or 
contact Dr. Jeff Hausdorff at jhausdor@bidmc.harvard.edu.