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visual3d:tutorials:modeling:building_a_conventional_gait_model [2025/03/03 18:10] – [Example 1: with CODA Pelvis - Steps:1a,2a,3b,4b,5b] wikisysopvisual3d:tutorials:modeling:building_a_conventional_gait_model [2025/03/03 18:49] (current) – [Example 3: with HH Pelvis with KAD - Steps:1b,2b,3a,4b,5a] wikisysop
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   - From the **Segment Type** box, select //Coda.//   - From the **Segment Type** box, select //Coda.//
   - Click **Create.**\\   - Click **Create.**\\
-  - A dialogue box labeled **CODA Segment Markers** will open. Select the markers so that they correspond to the figure below. Click **Close.**\\ {{:CODA_Pelvis_Markers1.jpg}}\\+  - A dialogue box labeled **CODA Segment Markers** will open. Select the markers so that they correspond to the figure below. Click **Close.**\\ \\ {{:CODA_Pelvis_Markers1.jpg}} \\ \\
   - Click **Build Model** to build the segment. You should now see a pelvis segment on your standing model. If you do not see the pelvis segment after clicking **Build Model**, double check the values you entered in the last step.   - Click **Build Model** to build the segment. You should now see a pelvis segment on your standing model. If you do not see the pelvis segment after clicking **Build Model**, double check the values you entered in the last step.
  
-== Bell and Brand Hip Joint Center - Step 2a ==+=== Bell and Brand Hip Joint Center - Step 2a ===
  
 The hip joint center calculation is based on a regression equation (Bell and Brand 1989) that will provide estimates of the distance from the pelvic origin to the hip joint center relative to the pelvic coordinate system. Inter-ASIS distance is the only measurement that is needed. The anthropometric section describes inter-ASIS distance measurement. It can be clinically measured or that distance can be calculated from the 3D positions of the ASIS markers. No measurements of leg length or ASIS to GT is needed. The hip joint center calculation is based on a regression equation (Bell and Brand 1989) that will provide estimates of the distance from the pelvic origin to the hip joint center relative to the pelvic coordinate system. Inter-ASIS distance is the only measurement that is needed. The anthropometric section describes inter-ASIS distance measurement. It can be clinically measured or that distance can be calculated from the 3D positions of the ASIS markers. No measurements of leg length or ASIS to GT is needed.
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 Estimates for the Right and Left Hip Joint Center are represented as Landmarks that are created automatically when the [[Visual3D:Documentation:Modeling:Segments:Coda_Pelvis|Coda_Pelvis]] segment is created. To view right and left hip joint centers, click on the **Landmarks** TAB. In the image below, the Landmarks are shown in blue. Estimates for the Right and Left Hip Joint Center are represented as Landmarks that are created automatically when the [[Visual3D:Documentation:Modeling:Segments:Coda_Pelvis|Coda_Pelvis]] segment is created. To view right and left hip joint centers, click on the **Landmarks** TAB. In the image below, the Landmarks are shown in blue.
  
-{{:CODA_Hip_Joint_Centers.jpg}}\\+{{:CODA_Hip_Joint_Centers.jpg}}
  
 +**Note:** that if the ASIS markers have been placed medial or lateral to the palpated landmark because the subject is obese or because the markers cannot be placed at these locations, it is important to measure the inter-ASIS distance and enter this value into the Subject Data/Metrics TAB. If this is not done, then the hip joint center calculations will be incorrect.
  
-**Note: that if the ASIS markers have been placed medial or lateral to the palpated landmark because the subject is obese or because the markers cannot be placed at these locations, it is important to measure the inter-ASIS distance and enter this value into the** Subject Data/Metrics **TAB. If this is not done, then the hip joint center calculations will be incorrect.** +=== Enter Subject Measurements ===
-== Enter Subject Measurements ==+
  
 The CODA pelvis does not require direct measurement. However, the conventional gait model does require measurement of knee and ankle width. To enter those measurements in Visual 3D, the user must create a **Subject Data Metric** for that measurement. The CODA pelvis does not require direct measurement. However, the conventional gait model does require measurement of knee and ankle width. To enter those measurements in Visual 3D, the user must create a **Subject Data Metric** for that measurement.
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 {{:CODA_subject_data_metrics_all.jpg}} {{:CODA_subject_data_metrics_all.jpg}}
  
-== Create Thigh Segments - Steps 3b and 4b ==+=== Create Thigh Segments - Steps 3b and 4b ===
  
 To create the right thigh segment: To create the right thigh segment:
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 {{:CODA_Thigh_segments.jpg}} {{:CODA_Thigh_segments.jpg}}
  
-== Create Knee Joint Centers ==+=== Create Knee Joint Centers ===
  
 The knee joint center of the Conventional Gait Model is assumed to be fixed in both the femur and tibia. It's location is half the knee width and half a marker diameter medial to the center of the lateral epicondyle marker in the plane of the femoral segment. The knee joint center of the Conventional Gait Model is assumed to be fixed in both the femur and tibia. It's location is half the knee width and half a marker diameter medial to the center of the lateral epicondyle marker in the plane of the femoral segment.
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-== Create Shank Segments - Steps 5b ==+=== Create Shank Segments - Steps 5b ===
  
 To create the right shank segment: To create the right shank segment:
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   - Click **Create.**   - Click **Create.**
  
-\\ 
 A dialog will open that will allow us to define the segment. To create a shank segment: A dialog will open that will allow us to define the segment. To create a shank segment:
  
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 {{:ConventionalGaitShankSegments.png}} {{:ConventionalGaitShankSegments.png}}
  
-== Create Ankle Joint Centers ==+=== Create Ankle Joint Centers ===
  
 As with the knee, the ankle joint center is assumed to be fixed in both the tibia and foot. It's location is half the ankle width and half a marker diameter medial to the center of the lateral malleolus marker in the plane of the tibial segment. As with the knee, the ankle joint center is assumed to be fixed in both the tibia and foot. It's location is half the ankle width and half a marker diameter medial to the center of the lateral malleolus marker in the plane of the tibial segment.
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-== Create Foot Segments ==+=== Create Foot Segments ===
  
 To create the right shank segment: To create the right shank segment:
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 {{:ConventionalGaitFootSegments.png}} {{:ConventionalGaitFootSegments.png}}
  
-=== Example 2: with HH pelvis & no KAD - Steps:1b,2c,3b,4b,5b ===+==== Example 2: with HH pelvis & no KAD - Steps:1b,2c,3b,4b,5b ====
  
-This section will detail the construction of the following version of the Conventional Gait Model. Click [[[https://www.has-motion.com/download/examples/Conventional%20Gait%20Model%20Tutorial%20Example%202.zip|Conventional Gait Example 2]]] to download example files.+This section will detail the construction of the following version of the Conventional Gait Model. Click [[https://www.has-motion.com/download/examples/Conventional%20Gait%20Model%20Tutorial%20Example%202.zip|Conventional Gait Example 2]] to download example files.
  
   * HH pelvis, Davis HJC with ASIS to GT regression, no KAD, no medial knee or ankle markers - Steps: 1b,2c,3b,4b,5b   * HH pelvis, Davis HJC with ASIS to GT regression, no KAD, no medial knee or ankle markers - Steps: 1b,2c,3b,4b,5b
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   - Click **Build Model** to build the segment. You should now see a pelvis segment on your standing model. If you do not see the pelvis segment after clicking **Build Model**, double check the values you entered in the last step.   - Click **Build Model** to build the segment. You should now see a pelvis segment on your standing model. If you do not see the pelvis segment after clicking **Build Model**, double check the values you entered in the last step.
  
-== Enter Subject Measurements ==+=== Enter Subject Measurements ===
  
 When Visual 3D creates the HH Pelvis, **Subject Data/Metrics** are created for the model. Since the hip joint center calculation for HH Pelvis model is based on inter-ASIS distance, leg length, and ASIS to GT distance, these values need to be entered into the **Subject Data/Metrics** Tab. In addition, knee and ankle width **Subject Data/Metrics** need to be created and entered. When Visual 3D creates the HH Pelvis, **Subject Data/Metrics** are created for the model. Since the hip joint center calculation for HH Pelvis model is based on inter-ASIS distance, leg length, and ASIS to GT distance, these values need to be entered into the **Subject Data/Metrics** Tab. In addition, knee and ankle width **Subject Data/Metrics** need to be created and entered.
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 {{:HH_Subject_Data_MetricsAll.jpg}} {{:HH_Subject_Data_MetricsAll.jpg}}
  
-== HJC Regression Without Clinical Measurement of ASIS to GT (Davis 1991) ==+=== HJC Regression Without Clinical Measurement of ASIS to GT (Davis 1991) ===
  
 The hip joint center calculation is based on a regression equation (Davis 1991) that will provide estimates of the distance from the pelvic origin to the hip joint center relative to the pelvic coordinate system. Measurements of leg length, anteroposterior ASIS to Greater Trochanter distance, and inter-ASIS distance are needed. The anthropometric section describes the measurements for leg length and inter-ASIS distance. The hip joint center calculation is based on a regression equation (Davis 1991) that will provide estimates of the distance from the pelvic origin to the hip joint center relative to the pelvic coordinate system. Measurements of leg length, anteroposterior ASIS to Greater Trochanter distance, and inter-ASIS distance are needed. The anthropometric section describes the measurements for leg length and inter-ASIS distance.
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 **Note: that if the ASIS markers have been placed medial or lateral to the palpated landmark because the subject is obese or because the markers cannot be placed at these locations, it is important to measure the inter-ASIS distance and enter this value into the** Subject Data/Metrics **TAB. If this is not done, then the hip joint center calculations will be incorrect.** **Note: that if the ASIS markers have been placed medial or lateral to the palpated landmark because the subject is obese or because the markers cannot be placed at these locations, it is important to measure the inter-ASIS distance and enter this value into the** Subject Data/Metrics **TAB. If this is not done, then the hip joint center calculations will be incorrect.**
-== Create Thigh Segments - Steps 3b and 4b ==+=== Create Thigh Segments - Steps 3b and 4b ===
  
 To create the right thigh segment: To create the right thigh segment:
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 {{:HH_Thigh_segment_all.jpg}} {{:HH_Thigh_segment_all.jpg}}
  
-== Create Knee Joint Centers ==+=== Create Knee Joint Centers ===
  
 The knee joint center of the Conventional Gait Model is assumed to be fixed in both the femur and tibia. It's location is half the knee width and half a marker diameter medial to the center of the lateral epicondyle marker in the plane of the femoral segment. The knee joint center of the Conventional Gait Model is assumed to be fixed in both the femur and tibia. It's location is half the knee width and half a marker diameter medial to the center of the lateral epicondyle marker in the plane of the femoral segment.
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-== Create Shank Segments - Steps 5b ==+=== Create Shank Segments - Steps 5b ===
  
 To create the right shank segment: To create the right shank segment:
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 {{:HH_Shank_segments.jpg}} {{:HH_Shank_segments.jpg}}
  
-== Create Ankle Joint Centers ==+=== Create Ankle Joint Centers ===
  
 As with the knee, the ankle joint center is assumed to be fixed in both the tibia and foot. It's location is half the ankle width and half a marker diameter medial to the center of the lateral malleolus marker in the plane of the tibial segment. As with the knee, the ankle joint center is assumed to be fixed in both the tibia and foot. It's location is half the ankle width and half a marker diameter medial to the center of the lateral malleolus marker in the plane of the tibial segment.
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-== Create Foot Segments ==+=== Create Foot Segments ===
  
 To create the right shank segment: To create the right shank segment:
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 {{:CODA_Foot_segments.jpg}} {{:CODA_Foot_segments.jpg}}
  
-=== Example 3: with HH Pelvis with KAD - Steps:1b,2b,3a,4b,5a ===+==== Example 3: with HH Pelvis with KAD - Steps:1b,2b,3a,4b,5a ====
  
-This section will detail the construction of the following version of the Conventional Gait Model. Click [[[https://www.has-motion.com/download/examples/Conventional%20Gait%20Model%20Tutorial%20Example%203.zip|Conventional Gait Example 3]]] to download example files.+This section will detail the construction of the following version of the Conventional Gait Model. Click [[https://www.has-motion.com/download/examples/Conventional%20Gait%20Model%20Tutorial%20Example%203.zip|Conventional Gait Example 3]] to download example files.
  
   * HH pelvis, Davis HJC with clinically measured ASIS to GT distance, with KAD, no medial knee, ankle markers - Steps:1b,2b,3a,4b,5a   * HH pelvis, Davis HJC with clinically measured ASIS to GT distance, with KAD, no medial knee, ankle markers - Steps:1b,2b,3a,4b,5a
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   - Visual3D will switch to Model Building mode automatically. The 3D viewer will display the average value of the marker locations from the standing file. The dialog bar to the left of the screen will contain a list of segments, which by default will contain only a segment representing the Laboratory.   - Visual3D will switch to Model Building mode automatically. The 3D viewer will display the average value of the marker locations from the standing file. The dialog bar to the left of the screen will contain a list of segments, which by default will contain only a segment representing the Laboratory.
  
-== Creating the HH Pelvis Segment ==+=== Creating the HH Pelvis Segment ===
  
 To construct the HH Pelvis (Davis) segment: To construct the HH Pelvis (Davis) segment:
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   - Click **Build Model** to build the segment. You should now see a pelvis segment on your standing model. If you do not see the pelvis segment after clicking **Build Model**, double check the values you entered in the last step.   - Click **Build Model** to build the segment. You should now see a pelvis segment on your standing model. If you do not see the pelvis segment after clicking **Build Model**, double check the values you entered in the last step.
  
-== Enter Subject Measurements ==+=== Enter Subject Measurements ===
  
 When Visual 3D creates the HH Pelvis, **Subject Data/Metrics** are created for the model. Since the hip joint center calculation for HH Pelvis model is based on inter-ASIS distance, leg length, and ASIS to GT distance, these values need to be entered into the **Subject Data/Metrics** Tab. When Visual 3D creates the HH Pelvis, **Subject Data/Metrics** are created for the model. Since the hip joint center calculation for HH Pelvis model is based on inter-ASIS distance, leg length, and ASIS to GT distance, these values need to be entered into the **Subject Data/Metrics** Tab.
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   - Click **Build Model** to build the segment. The hip joint centers should now be calculated properly. For further disussion on the hip joint center calculations see the Joint Center Calculations section.   - Click **Build Model** to build the segment. The hip joint centers should now be calculated properly. For further disussion on the hip joint center calculations see the Joint Center Calculations section.
  
-== HJC Regression with Clinical Measurement of ASIS to GT (Davis 1991) ==+=== HJC Regression with Clinical Measurement of ASIS to GT (Davis 1991) ===
  
 The hip joint center calculation is based on a regression equation (Davis 1991) that will provide estimates of the distance from the pelvic origin to the hip joint center relative to the pelvic coordinate system. Measurements of leg length, anteroposterior ASIS to Greater Trochanter distance, and inter-ASIS distance are needed. The anthropometric section describes the measurements for leg length, anteroposterior ASIS to Greater Trochanter distance, and inter-ASIS distance. The regression equation was shown in the Hip joint center calculations in Example 2. The hip joint center calculation is based on a regression equation (Davis 1991) that will provide estimates of the distance from the pelvic origin to the hip joint center relative to the pelvic coordinate system. Measurements of leg length, anteroposterior ASIS to Greater Trochanter distance, and inter-ASIS distance are needed. The anthropometric section describes the measurements for leg length, anteroposterior ASIS to Greater Trochanter distance, and inter-ASIS distance. The regression equation was shown in the Hip joint center calculations in Example 2.
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 **Note: that if the ASIS markers have been placed medial or lateral to the palpated landmark because the subject is obese or because the markers cannot be placed at these locations, it is important to measure the inter-ASIS distance and enter this value into the** Subject Data/Metrics **TAB. If this is not done, then the hip joint center calculations will be incorrect.** **Note: that if the ASIS markers have been placed medial or lateral to the palpated landmark because the subject is obese or because the markers cannot be placed at these locations, it is important to measure the inter-ASIS distance and enter this value into the** Subject Data/Metrics **TAB. If this is not done, then the hip joint center calculations will be incorrect.**
-== Create KAD Segments - Steps 3a ==+=== Create KAD Segments - Steps 3a ===
  
 We must make a virtual segment (kinematic only) for the KAD. To create a //Kinematic Only// right KAD segment: We must make a virtual segment (kinematic only) for the KAD. To create a //Kinematic Only// right KAD segment:
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 **Note: Many laboratories have taken to replacing the 25 mm markers with smaller markers, in an erroneous assumption that it would be a good idea to have all markers used on the body and the KAD to be the same size. This actually introduces an error in the assumptions of how the KAD is used. If this is done, the user must be careful to accommodate this change to the original assumptions.** **Note: Many laboratories have taken to replacing the 25 mm markers with smaller markers, in an erroneous assumption that it would be a good idea to have all markers used on the body and the KAD to be the same size. This actually introduces an error in the assumptions of how the KAD is used. If this is done, the user must be careful to accommodate this change to the original assumptions.**
  
-== Edit Subject Metrics and Landmarks ==+=== Edit Subject Metrics and Landmarks ===
  
 When the KAD segments are created, Visual 3D creates the Knee and Ankle width subject metrics from default values. These need to be edited to reflect the current subject. #Click on **Subject Data/Metrics** tab and enter the values by selecting **Modify Selected Item** for each of the items below: When the KAD segments are created, Visual 3D creates the Knee and Ankle width subject metrics from default values. These need to be edited to reflect the current subject. #Click on **Subject Data/Metrics** tab and enter the values by selecting **Modify Selected Item** for each of the items below:
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 {{:HH_Subject_Data_Metrics_KAD_All1.jpg}} {{:HH_Subject_Data_Metrics_KAD_All1.jpg}}
  
-== Create Thigh Segments - Steps 4b ==+=== Create Thigh Segments - Steps 4b ===
  
 To create the right thigh segment: To create the right thigh segment:
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 {{:HH_KAD_Thigh_segment_all.jpg}} {{:HH_KAD_Thigh_segment_all.jpg}}
  
-== Knee Joint Centers ==+=== Knee Joint Centers ===
  
 The knee joint center of the Conventional Gait Model is assumed to be fixed in both the femur and tibia. It's location is half the knee width and half a marker diameter medial to the center of the lateral epicondyle marker in the plane of the femoral segment. When we constructed the KAD thigh segments, we used these calculations to define the distal joint and radius. The knee joint center was explicitly defined the by creating a landmark at the distal end of the thigh segment. Those markers are //HH_LEFT_KNEE_FROM_KAD// and //HH_RIGHT_KNEE_FROM_KAD//. To view the knee joint center landmarks, click on the **Landmarks** TAB. The knee joint center of the Conventional Gait Model is assumed to be fixed in both the femur and tibia. It's location is half the knee width and half a marker diameter medial to the center of the lateral epicondyle marker in the plane of the femoral segment. When we constructed the KAD thigh segments, we used these calculations to define the distal joint and radius. The knee joint center was explicitly defined the by creating a landmark at the distal end of the thigh segment. Those markers are //HH_LEFT_KNEE_FROM_KAD// and //HH_RIGHT_KNEE_FROM_KAD//. To view the knee joint center landmarks, click on the **Landmarks** TAB.
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 {{:HH_KAD_KJC.jpg}} {{:HH_KAD_KJC.jpg}}
  
-== Create Shank Segments - Steps 5b ==+=== Create Shank Segments - Steps 5b ===
  
 To create the right shank segment: To create the right shank segment:
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 {{:HH_Shank_segments.jpg}} {{:HH_Shank_segments.jpg}}
  
-== Create Ankle Joint Centers ==+=== Create Ankle Joint Centers ===
  
 As with the knee, the ankle joint center is assumed to be fixed in both the tibia and foot. It's location is half the ankle width and half a marker diameter medial to the center of the lateral malleolus marker in the plane of the tibial segment. As with the knee, the ankle joint center is assumed to be fixed in both the tibia and foot. It's location is half the ankle width and half a marker diameter medial to the center of the lateral malleolus marker in the plane of the tibial segment.
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-== Create Foot Segments ==+=== Create Foot Segments ===
  
 To create the right shank segment: To create the right shank segment:
visual3d/tutorials/modeling/building_a_conventional_gait_model.1741025434.txt.gz · Last modified: 2025/03/03 18:10 by wikisysop