The Ground Reaction Force has 9 components. 3 components for the Force (FORCE), 3 components for the Center of Pressure (COFP), and 3 components for the Free Moment (FREEMOMENT).

The Free Moment is typically the z-component (in the Force Platform Coordinate System) of the Ground Reaction Force Vector. The assumption behind the single component is that it is not possible to cause a Couple about the x and y axis during normal activity.

NOTE

When Visual3D calculates the ground reaction force, it uses the location of the force platform corners to transform the signals into the laboratory coordinate system. This transformation usually results in the z-axis of the force platform not being colinear with the vertical direction in the laboratory, thus there are components of the FREEMOMENT about all three laboratory axes. In most cases, two of the components are very small.

This data type is populated by:

Force_Platforms Force_Structures