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--- visual3d:documentation:modeling:segments:pelvis_segment_angle [2024/06/19 13:58] – created sgranger
+++ visual3d:documentation:modeling:segments:pelvis_segment_angle [2024/08/26 19:36] (current) – [Examples] wikisysop
@@ Line 1: / Line 1: @@
+====== Pelvis Segment Angle ======
 The Pelvis Angle typically refers to the orientation of the Pelvis relative to the Laboratory.
-===== Sequence of rotations for pelvis angle =====
+==== Sequence of rotations for pelvis angle ====
 In the following Technical Note:
@@ Line 14: / Line 16: @@
 **Note 2:** For the calculation of segment angles, it is assumed that the subject is moving such that the lateral direction in the laboratory is the same as the lateral direction of the subject. If the subject turns relative to the laboratory, you will get strange results. Visual3D allows you to define a Virtual Laboratory (see elsewhere on this page) to avoid this problem.
-===== Examples =====
+==== Examples ====
 We have listed a few examples for your review.
-==== Example 1: Pelvis Relative to Virtual Lab ====
+=== Example 1: Pelvis Relative to Virtual Lab ===
 Segment angles are often defined as the orientation of a segment relative to the laboratory. The calculations and parameters are equivalent to the Joint Angle calculations except that the reference segment is the laboratory.
@@ Line 28: / Line 30: @@
 To accommodate the comparison of these trials you can create a Virtual Laboratory segment that is aligned with the direction of walking in the movement trial. An example file (Example2) can be found on the [[Visual3D:Documentation:Modeling:Virtual_Lab:Virtual_Lab|Example: Virtual Lab]] page. In the example file, the foot and pelvis angles are defined relative to the laboratory (LAB) for walking in the +y direction and relative to the virtual laboratory (VLB) for walking in the -y direction.
-==== Example 2: Pelvis Relative to Virtual Lab that Changes Direction ====
+=== Example 2: Pelvis Relative to Virtual Lab that Changes Direction ===
 The subject is walking in the anterior direction of the laboratory in some of the trials and in the posterior direction of the laboratory in other trials. How can I set up a virtual laboratory that will consistently give the angle of the pelvis relative to the walking direction?
@@ Line 36: / Line 38: @@
 To accommodate the comparison of these trials you can create a Virtual Laboratory segment that is aligned with the direction of walking in the movement trial. The [[Visual3D:Documentation:Modeling:Virtual_Lab:Virtual_Lab_That_Changes_Direction|Example: Virtual Lab That Changes Direction]] page will show you have to create a laboratory lateral landmark that is oriented in the same direction as the lateral direction of the pelvis. There you will find an example file to download (Example3).
-==== Example 3: Pelvis Relative to Virtual Lab that is at 45 Degrees ====
+=== Example 3: Pelvis Relative to Virtual Lab that is at 45 Degrees ===
 I have recorded data of straight walking using lower limb markers and pelvis markers. As the medial-lateral offset of the two force plates has been insufficient for my subjects, they therefore decided to angle their straight walk in such a way that they hit the force plates in a slightly oblique manner. My subjects’ straight walking direction is therefore not truly parallel with respect to the global coordinate system. How can I compute the pelvis segment angle (e.g. relative to the laboratory coordinate system).
@@ Line 46: / Line 48: @@
 Let's create the following landmarks:
-Landmark Name= **Lab_Origin**
+Landmark Name= **Lab_Origin**\\
-Starting Point= Enter nothing
+Starting Point= Enter nothing\\
-Existing Segment= **LAB**
+Existing Segment= **LAB**\\
-Offset Using the Following ML/AP/AXIAL Offset= X=**0** , Y=**0** , Z=**0**
+Offset Using the Following ML/AP/AXIAL Offset= X=**0** , Y=**0** , Z=**0**\\
 Calibration Only Landmark= Leave Unchecked
-Landmark Name= **Lab_Anterior**
-Starting Point= Enter nothing
+Landmark Name= **Lab_Anterior**\\
-Existing Segment= **LAB**
+Starting Point= Enter nothing\\
-Offset Using the Following ML/AP/AXIAL Offset= X=**0.707** , Y=**0.707** , Z=**0**
+Existing Segment= **LAB**\\
-Calibration Only Landmark= Leave Unchecked
+Offset Using the Following ML/AP/AXIAL Offset= X=**0.707** , Y=**0.707** , Z=**0**\\
-Landmark Name= **Lab_Z**
-Starting Point= Enter nothing
-Existing Segment= **LAB**
-Offset Using the Following ML/AP/AXIAL Offset= X=**0** , Y=**0** , Z=**0.1**
 Calibration Only Landmark= Leave Unchecked
+Landmark Name= **Lab_Z**\\
+Starting Point= Enter nothing\\
+Existing Segment= **LAB**\\
+Offset Using the Following ML/AP/AXIAL Offset= X=**0** , Y=**0** , Z=**0.1**\\
+Calibration Only Landmark= Leave Unchecked\\
 Let's create the Virtual Lab Segment:
-In the Segment Name combo box type **Virtual Lab**
+In the Segment Name combo box type **Virtual Lab**\\
-Select Segment Type = **Visual3D**.
+Select Segment Type = **Visual3D**.\\
-**Check the Kinematic Only Check Box**
+**Check the Kinematic Only Check Box**\\
-Select the **Create** button
+Select the **Create** button\\
-In the Segment dialog box, enter the following:
+In the Segment dialog box, enter the following:\\
+Define Proximal Joint and Radius\\
+Lateral= None Joint= **Lab_Z** Medial=None Radius= **0.01**\\
+Define Distal Joint and Radius\\
+Lateral= None Joint= **Lab_Origin** Medial= None Radius= **0.01**\\
+Extra Target To Define Orientation (if needed)\\
+Location= **Anterior** and **Lab_Anterior**\\
+**Select Tracking Markers same as Calibration Markers**\\
-Define Proximal Joint and Radius
-Lateral= None Joint= **Lab_Z** Medial=None Radius= **0.01**
-Define Distal Joint and Radius
-Lateral= None Joint= **Lab_Origin** Medial= None Radius= **0.01**
-Extra Target To Define Orientation (if needed)
-Location= **Anterior** and **Lab_Anterior**
-**Select Tracking Markers same as Calibration Markers**
 When creating the pelvis segment angle, select this Virtual Lab as the reference segment.