Normalized Joint Angle Method 1 - (Under construction....)
One method for setting the Ankle Joint Angle to Zero degrees in the standing trial is to define the Segment Coordinate System for the Virtual Foot Segment to be aligned precisely with the Segment Coordinate System for the Shank.
This can be accomplished by using the same proximal and distal targets.
Note: this definition assumes that the posture in the standing trial is to be considered an ankle angle of zero degrees regardless of the actual posture.
| 6. Create Right Virtual Foot Segment:
In the Segments tab, type Right Virtual Foot in the Segment Name box.
Check Kinematic Only
Click on the Create Segment button.
In the Right Virtual Foot tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Select Tracking Targets: |
Click on Build Model. A 3D image of a foot will appear over the shank segment. NOTE: The image of the foot can be removed by deleting the associated .v3g file from the Segment Properties tab.
Click on Close Tab before proceeding. |  |
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NOTE Since the two segment coordinate systems are perfectly aligned the segments have identical orientation in the standing trial and hence have a joint angle of zero degrees.
(The segment coordinate system in this section will not need to be rotated to follow the convention in the rest of the tutorial)