Define the foot segments using the anterior-posterior axis LHEE/RHEE to LTOE/RTOE as their major axes.
Note that the minor axis in CGM is not yet defined in CGM2.3: this is added in the next version (CGM2.4). (This can also be implemented in ProCalc, but is not part of this tutorial.)
To define the feet:
- Create two vectors, LFootAP and RFootAP, from LHEE/RHEE to LTOE/RTOE.
- Create two segments, L_Foot and R_Foot, using Origin A, X-axis=B, Z-Axis=BxC, specifying A=LAJC/RAJC, B=LFootAP/RFootAP and C=LTibiaML/RTibiaML.
When defining the L_Foot, flip the LTibiaML.
To define foot flat for the static trial, when defining the feet, change the XYZ drop-down for the LFootAP/RFootAP and LTibiaML/RTibiaML vectors to XY instead of XYZ.
The Z-coordinate of the vectors is ignored, and the foot is modeled as flat on the ground in the static trial.