HAS-Motion Software Documentation

User Tools

Site Tools

You are here: Main Page » visual3d » tutorials » modeling » Building a Conventional Gait Model
visual3d:tutorials:modeling:building_a_conventional_gait_model

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision		Previous revision
visual3d:tutorials:modeling:building_a_conventional_gait_model [2025/03/03 18:44] – [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
Line 479: Line 479:
 ==== 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
Line 508: Line 508:
   - 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.
Line 538: Line 538:
 {{: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.
Line 581: Line 581:
  
 **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:
Line 622: Line 622:
 {{: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.
Line 656: Line 656:
  
  
-== Create Shank Segments - Steps 5b ==+=== Create Shank Segments - Steps 5b ===
  
 To create the right shank segment: To create the right shank segment:
Line 698: Line 698:
 {{: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.
Line 732: Line 732:
  
  
-== Create Foot Segments ==+=== Create Foot Segments ===
  
 To create the right shank segment: To create the right shank segment:
Line 772: Line 772:
 {{: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
Line 788: Line 788:
   - 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:
Line 803: Line 803:
   - 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.
Line 817: Line 817:
   - 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.
Line 827: Line 827:
  
 **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:
Line 858: Line 858:
 **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:
Line 876: Line 876:
 {{: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:
Line 916: Line 916:
 {{: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.
Line 922: Line 922:
 {{: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:
Line 964: Line 964:
 {{: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.
Line 998: Line 998:
  
  
-== 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.1741027445.txt.gz · Last modified: 2025/03/03 18:44 by wikisysop