Creating Force Assignment

In the case of gait or running analysis, it is often useful to have a visual indication of which foot touches the force plate on a force graph. If the hardware configuration you are using contains one or more force plates, the Create Force Assignment script will automatically detect if the force plates have been touched by the right or left foot. By default, the script uses the “R.Heel” and “L.Heel” markers to make this determination. It is not currently possible to change these two markers through a menu. If a force plate has been simultaneously touched by the two feet, the script will define this period as unknown.

The automatic force assignment script can be added to the current protocol by selecting the “Create Force Assignment …” item in the “Calculation” Menu (Figure 1).

Figure 1: Create Force Assignment

This script is a user input script which means that it has to be manually launched by double clicking on the “Force Assignment” item (or right click and select “run script”) as shown Figure 2.

Figure 2: Running the force assignment script

If the option “Show Force Segments” is ticked in a graph menu (see Figure 3) then the period where the foot touched the force plate will be highlighted (see Figure 4)

Figure 3: Show Force Segment

Figure 4: Highlighted area

The area will be red or blue depending if the force plate has been touched by the right or left foot (respectively). If the script hasn’t been able to determine if the force plate has been touched by the right or left foot then it will set it as “Unknown” and the colour will be grey.

If you wish to change the assignment set by the script, you can manually set the area by right clicking on it and choosing one of the option: “Set left”, “Set right” or “Set unknown” (see figure 5).

Figure 5: Setting the area manually

Note that if you change the settings and re-run the script then the script will overwrite your manual changes.