====== Create CODA pelvis relative to anatomical landmarks ======

Create CODA pelvis relative to anatomical landmarks.

The segment coordinate system for the CODA pelvis is the mid-point between the ASIS markers. The anatomical landmarks are actually posterior to the ASIS markers because the motion capture system tracks the center of the marker.

This is a modest error, but it can be corrected by creating landmarks that are posterior to the ASIS markers by the radius of the motion capture marker.

=== Step 1. Confirm the subject metric containing the marker radius. ===

If the metric doesn't exist, create a new metric.

Switch to **Subject Data/Metrics** TAB.

{{:SegmentExample4_1.png}}\\


Select **Add New Item** and enter in the name **Marker_Radius** and the value.

{{:SegmentExample4_2.png}}\\


In this example, the marker has a diameter of 1.2 cm. Visual3D uses MKS units, so the value is 0.006 meters.

**Note:** If the radius is not consistent with your marker radius, modify the value.

=== Step 2. Create landmarks for the ASIS markers ===

{{:SegmentExample4_4.png}}\\


**Note:** the ML Edit box contains the expression **-MARKER_RADIUS**

{{:SegmentExample4_5.png}}\\


**Note:** the ML Edit box contains the expression **-MARKER_RADIUS**

=== Step 3. Create a CODA Pelvis ===

{{:SegmentExample4_6.png}}\\


In this example, the locations defining the segment coordinate system for the pelvis are the landmarks **RT_ASIS** and **LT_ASIS**, and the marker **SACR** located at the midpoint of the PSIS markers.

The tracking markers are **RASI**, **LASI**, and **SACR**.

{{:SegmentExample4_7.png}}\\