Data format:
------------

Each line contains 19 columns:

Column      1:   Time (in seconds)
Columns   2-9:   Vertical ground reaction force (VGRF, in Newton) on each of 8
	  	  sensors located under the left foot
Columns 10-17:   VGRF on each of the 8 sensors located under the right foot
Column     18:   Total force under the left foot
Column     19:   Total force under the right foot.

When a person is comfortably standing with both legs parallel to each
other, sensor locations inside the insole can be described (according
to the Infotronic website; http://www.infotronic.nl/) as lying
approximately at the following (X,Y) coordinates, assuming that the
origin (0,0) is just between the legs and the person is facing towards
the positive side of the Y axis:

Sensor       X      Y
----------------------------
L1         -500   -800
L2         -700   -400
L3         -300   -400
L4         -700      0
L5         -300      0
L6         -700    400
L7         -300    400
L8         -500    800

R1          500   -800
R2          700   -400
R3          300   -400
R4          700      0
R5          300      0
R6          700    400
R7          300    400
R8          500    800

The X and Y numbers are in an arbitrary coordinate system reflecting
the relative (arbitrarily scaled) positions of the sensors within each
insole. During walking, the sensors inside each insole remain at the
same relative position, but the two feet are no longer parallel to
each other. Thus, this coordinate system enables a calculation of a
proxy for the location of the center of pressure (COP) under each
foot.


Data file names:
----------------
These follow a common convention, e.g., GaCo01_02.txt  or  JuPt03_06.txt,
where

Ga, Ju or Si – indicate the study from which the data originated:
    Ga - Galit Yogev et al (dual tasking in PD; Eur J Neuro, 2005)
    Ju – Hausdorff et al (RAS in PD; Eur J Neuro, 2007)
    Si - Silvi Frenkel-Toledo et al (Treadmill walking in PD; Mov Disorders,
          2005)

Co or Pt: Control subject or a PD Patient

01: Subject number in the group

A walk number of 10  (for the "Ga" study) indicates a dual-task walking,
where the subject was engaged in serial-7 subtraction while walking.

A walk number of 01 refers to a usual, normal walk. 

.txt: file name extension

The sampling rate was 100 Hz.