Ground reaction forces were measured using two 6 degrees of freedom force plates (AMTI, Watertown, MA). The coordinate system is a right-handed system.
|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).
(see Comprehensive Data Sample (http://orthoload.com/comprehensive-data-sample/)):
|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|
(Downsampled Ground Reaction Forces)
|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|