Ground reactions forces

Ground reaction forces were measured using two 6 degrees of freedom force plates (AMTI, Watertown, MA). The coordinate system is a right-handed system.

Raw data:

VARIABLE	DESCRIPTION	UNITS	SAMPLE RATE
Fx,y,z 1/2	Ground reaction forces, forceplate 1 and 2	N	960Hz
Mx,y,z 1/2	Moments relative to the original forceplate coordinate system, forceplate 1 and 2	Nmm	960Hz

For the calculation of the center of pressure the following offsets were used. The true origins of the coordinate systems are located below the top surfaces, with a distance (zo).

Processed data

(see Comprehensive Data Sample (http://orthoload.com/comprehensive-data-sample/)):

VARIABLE	DESCRIPTION	UNITS	SAMPLE RATE
Fgrx,y,zi	Ground reaction forces, ipsilateral leg	N	90-110 Hz
COP_x,yi	Center of pressure, relative to forceplate center, ipsilateral leg	mm	90-110 Hz
Tz_o	Torque around z-axis at CoP, ipsilateral leg	Nm	90-110 Hz

grf2f.eof data:

(Downsampled Ground Reaction Forces)

VARIABLE	DESCRIPTION	UNITS	SAMPLE RATE
Fgrxi,yi,zi	Ground reaction forces, ipsilateral leg	N	90-110 Hz
Fgrxc,yc,zc	Ground reaction forces, contralateral leg	N	90-110 Hz
F	Resultant joint contact force (implant)	N	90-110 Hz