Define the tibia segments in the same way as the femur segments:
- Calculate the ankle joint centers halfway between the lateral and medial ankle markers.
- Use the LAJC/RAJC to LKJC/RKJC vectors as the proximal/distal (major) axes.
- Use the LANK/RMED to LMED/RANK vectors as the mediolateral (minor) axes for the L_Tibia and R_Tibia segments.