---
title: "Defining the tibia segments"
canonical: "https://help.vicon.com/space/ProCalc16/12651105/Defining%20the%20tibia%20segments"
format: markdown
---
Define the tibia segments in the same way as the [femur segments](https://vicon-help.atlassian.net/wiki/spaces/ProCalc16/pages/12648494):

- 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.