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 16:27] – [Hip Joint Center] 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 70: Line 70:
 === Four Marker Set Pelvis - CODA Pelvis === === Four Marker Set Pelvis - CODA Pelvis ===
  
-{{:Pelvis_segment_markers4.jpeg}}+{{:Pelvis_segment_markers4jpeg.jpg?400}}
  
 RIAS , LIAS= Right Ilium Anterior Superior (Anterior Superior Iliac Spine)\\ RIAS , LIAS= Right Ilium Anterior Superior (Anterior Superior Iliac Spine)\\
 RIPS , LIPS= Left Ilium Posterior Superior (Posterior Superior Iliac Spine) RIPS , LIPS= Left Ilium Posterior Superior (Posterior Superior Iliac Spine)
-\\+ 
 As with the [[Visual3D:Documentation:Modeling:Segments:Helen_Hayes_(Davis)_Pelvis|Helen Hayes (Davis) Pelvis]], the plane of the [[Visual3D:Documentation:Modeling:Segments:Coda_Pelvis|Coda Pelvis]] is visualized as a triangle or plane. In this case the plane is formed by the Right and Left Anterior Superior Iliac Spines (RIAS and LIAS) and the mid point of the Right and Left Posterior Superior Iliac Spines (RIPS, LIPS). Place the centers of the markers over both Anterior Superior Iliac Spines (ASIS's) and both Posterior Superior Iliac Spines (PSIS's). As with the [[Visual3D:Documentation:Modeling:Segments:Helen_Hayes_(Davis)_Pelvis|Helen Hayes (Davis) Pelvis]], the plane of the [[Visual3D:Documentation:Modeling:Segments:Coda_Pelvis|Coda Pelvis]] is visualized as a triangle or plane. In this case the plane is formed by the Right and Left Anterior Superior Iliac Spines (RIAS and LIAS) and the mid point of the Right and Left Posterior Superior Iliac Spines (RIPS, LIPS). Place the centers of the markers over both Anterior Superior Iliac Spines (ASIS's) and both Posterior Superior Iliac Spines (PSIS's).
  
Line 81: Line 82:
 === Three Marker Set Pelvis - Helen Hayes (Davis) Pelvis === === Three Marker Set Pelvis - Helen Hayes (Davis) Pelvis ===
  
-{{:Pelvis_segment_markers3.jpeg}}+{{:Pelvis_segment_markers3jpeg.jpg?400}}
  
 RIAS , LIAS= Right Ilium Anterior Superior (Anterior Superior Iliac Spine)\\ RIAS , LIAS= Right Ilium Anterior Superior (Anterior Superior Iliac Spine)\\
Line 109: Line 110:
 ==== Upper Leg Markers ==== ==== Upper Leg Markers ====
  
-{{:Thigh_segment_markers3.jpeg}}+{{:Thigh_segment_markers3jpeg.jpg?400}}
  
 RFCH, LFCH=Femur Center of Head\\ RFCH, LFCH=Femur Center of Head\\
Line 150: Line 151:
 ==== Lower Leg Markers ==== ==== Lower Leg Markers ====
  
-{{:Shank_segment_markers4.jpeg}}+{{:Shank_segment_markers4jpeg.jpg?400}}
  
 RFLE, LFLE=Femur Lateral Epicondyle\\ RFLE, LFLE=Femur Lateral Epicondyle\\
Line 204: Line 205:
  
 |                                                                                                                                                                               Variable                                                                                                                                                                                |Helen Hayes Pelvis 1|Helen Hayes Pelvis 2|CODA Pelvis|Visual 3D Default Calculations                                                                                                                                                                                           | |                                                                                                                                                                               Variable                                                                                                                                                                                |Helen Hayes Pelvis 1|Helen Hayes Pelvis 2|CODA Pelvis|Visual 3D Default Calculations                                                                                                                                                                                           |
-|                                                                                                                                                    **Height:** Remember to account for crouched standing posture.                                                                                                                                                     |X                   |X                   |X          |None                                                                                                                                                                                                                     | +|**Height:** Remember to account for crouched standing posture.                                                                                                                                                     |X                   |X                   |X          |None                                                                                                                                                                                                                     | 
-|                                                                                                                                                        **Weight:** Weight is measured without shoes or braces.                                                                                                                                                        |X                   |X                   |X          |None                                                                                                                                                                                                                     | +|**Weight:** Weight is measured without shoes or braces.                                                                                                                                                        |X                   |X                   |X          |None                                                                                                                                                                                                                     | 
-|                  **Inter-ASIS distance:** The three dimensional reconstruction of ASIS markers may be used, but it is often difficult to place markers on the ASIS on subjects that are overweight.\\ \\ * Clinically Measured ASIS Distance\\ * Calculated ASIS Distance: from 3D distance between ASIS markers\\ * Adjustments for Obese Subjects                   |X                   |X                   |X          |3D distance between ASIS markers, but the user can enter a measurement.                                                                                                                                                  | +|**Inter-ASIS distance:** The three dimensional reconstruction of ASIS markers may be used, but it is often difficult to place markers on the ASIS on subjects that are overweight.\\ \\ * Clinically Measured ASIS Distance\\ * Calculated ASIS Distance: from 3D distance between ASIS markers\\ * Adjustments for Obese Subjects                   |X                   |X                   |X          |3D distance between ASIS markers, but the user can enter a measurement.                                                                                                                                                  | 
-|         **Bilateral anteroposterior distance (ASIS to GT):** The anteroposterior distance from the ASIS to the greater trochanter.\\ \\ * Clinically ASIS to GT: If there is asymmetry, use the side that appears to be most normal rather than an average. Measure with patient supine.\\ * Calculated from a regression equation: 0.1288*Leg Length-0.04856         |X                   |X                   |           |0.1288*Leg Length-0.04856                                                                                                                                                                                                | +|**Bilateral anteroposterior distance (ASIS to GT):** The anteroposterior distance from the ASIS to the greater trochanter.\\ \\ * Clinically ASIS to GT: If there is asymmetry, use the side that appears to be most normal rather than an average. Measure with patient supine.\\ * Calculated from a regression equation: 0.1288*Leg Length-0.04856         |X                   |X                   |           |0.1288*Leg Length-0.04856                                                                                                                                                                                                | 
-|  **Bilateral leg length:** Measured as the distance between the ASIS and the malleolus.\\ \\ * Clinically Measured: should be measured as the distance between the ASIS and the medial malleolus. If the legs are of different lengths, the user should enter the leg length of the more normal leg.\\ * Calculated from: distance from ASIS to Proximal Foot Marker  |X                   |X                   |           |* **Right Leg length =**distance from Right ASIS to Right Proximal Foot Marker\\ * **Left Leg length =**distance from Left ASIS to Left Proximal Foot Marker\\ * **Leg Length =**0.5*(Right Leg Length + Left Leg Length)| +|**Bilateral leg length:** Measured as the distance between the ASIS and the malleolus.\\ \\ * Clinically Measured: should be measured as the distance between the ASIS and the medial malleolus. If the legs are of different lengths, the user should enter the leg length of the more normal leg.\\ * Calculated from: distance from ASIS to Proximal Foot Marker  |X                   |X                   |           |* **Right Leg length =**distance from Right ASIS to Right Proximal Foot Marker\\ * **Left Leg length =**distance from Left ASIS to Left Proximal Foot Marker\\ * **Leg Length =**0.5*(Right Leg Length + Left Leg Length)| 
-|                                                                                                                  **Width of the bilateral knees:** Should be measured at the same level as the markers used to identify the flexion/extension axes.                                                                                                                   |X                   |X                   |X          |**Knee Width=**0.086                                                                                                                                                                                                     | +|**Width of the bilateral knees:** Should be measured at the same level as the markers used to identify the flexion/extension axes.                                                                                                                   |X                   |X                   |X          |**Knee Width=**0.086                                                                                                                                                                                                     | 
-|                                                                                                             **Width of the bilateral ankles:** Should be measured at the same level as the markers used to identify the plantarflexion/dorsiflexion axes.                                                                                                             |X                   |X                   |X          |**Ankle Width=**0.056                                                                                                                                                                                                    | +|**Width of the bilateral ankles:** Should be measured at the same level as the markers used to identify the plantarflexion/dorsiflexion axes.                                                                                                             |X                   |X                   |X          |**Ankle Width=**0.056                                                                                                                                                                                                    | 
-|                                                                          **Width of the foot:** Should be measured from the first to the fifth metatarsal. If the foot marker is placed above the third metatarsal, measure the vertical distance from the marker to the center of the foot.                                                                          |X                   |X                   |X          |**Foot Width=**0.056                                                                                                                                                                                                     |+|**Width of the foot:** Should be measured from the first to the fifth metatarsal. If the foot marker is placed above the third metatarsal, measure the vertical distance from the marker to the center of the foot.                                                                          |X                   |X                   |X          |**Foot Width=**0.056                                                                                                                                                                                                     |
  
-==== Conventional Gait Model Construction - 3 examples ====+===== Conventional Gait Model Construction - 3 examples =====
  
 This tutorial will not construct every variation of the conventional gait model but will cover 3 variations of the model. This tutorial will not construct every variation of the conventional gait model but will cover 3 variations of the model.
Line 221: Line 222:
   * Example 3: HH pelvis, Davis HJC with ASIS to GT regression, with KAD, no medial knee, ankle markers - Steps: 1b,2c,3a,4b,5a   * Example 3: HH pelvis, Davis HJC with ASIS to GT regression, with KAD, no medial knee, ankle markers - Steps: 1b,2c,3a,4b,5a
  
-=== Example 1: with CODA Pelvis - Steps:1a,2a,3b,4b,5b ===+==== Example 1: with CODA Pelvis - Steps:1a,2a,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%201.zip|Conventional Gait Example 1]]] to download the 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%201.zip|Conventional Gait Example 1]] to download the example files.
  
   * CODA pelvis, Bell and Brand HJC, no KAD, no medial knee or ankle markers - Steps: 1a,2a,3b,4b,5b   * CODA pelvis, Bell and Brand HJC, no KAD, no medial knee or ankle markers - Steps: 1a,2a,3b,4b,5b
Line 230: Line 231:
  
   - From the **Model** menu, select **Create (Add Static Calibration File)**\\   - From the **Model** menu, select **Create (Add Static Calibration File)**\\
-{{:tutorial1_2.jpg}}\\ +{{:tutorial1_2.jpg}}\\ \\
   - Select **Hybrid Model from C3DFile**   - Select **Hybrid Model from C3DFile**
   - A dialog titled **Select the calibration file for the new model** will appear. Select //static.c3d// and click **Open.**\\   - A dialog titled **Select the calibration file for the new model** will appear. Select //static.c3d// and click **Open.**\\
- 
   - 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 CODA Pelvis Segment - Step 1a ==+=== Creating the CODA Pelvis Segment - Step 1a === 
 +  - In the Subject Data/Metrics change the subjects mass and height. or this example, Enter //56// kg and //1.77// m, and click **OK.**\\
  
 To construct the CODA Pelvis segment: To construct the CODA Pelvis segment:
Line 244: Line 244:
   - From the **Segment Type** box, select //Coda.//   - From the **Segment Type** box, select //Coda.//
   - Click **Create.**\\   - Click **Create.**\\
-{{:CODA_pelvis1.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}} \\ \\
- +
-  - A dialogue box labeled **Enter Body Mass and Height** will open because Visual3D needs the subject to be assigned a mass and a height. For this example, Enter //56// kg and //1.77// m, and click **OK.**\\ +
-{{:26_weight.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.
Line 267: Line 260:
 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.
Line 294: Line 287:
 {{: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:
Line 337: Line 330:
 {{: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.
Line 371: Line 364:
  
  
-== Create Shank Segments - Steps 5b ==+=== Create Shank Segments - Steps 5b ===
  
 To create the right shank segment: To create the right shank segment:
Line 380: Line 373:
   - 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:
  
Line 411: Line 403:
 {{: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.
Line 445: Line 437:
  
  
-== Create Foot Segments ==+=== Create Foot Segments ===
  
 To create the right shank segment: To create the right shank segment:
Line 485: Line 477:
 {{: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
Line 516: 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 546: 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 589: 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 630: 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 664: 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 706: 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 740: Line 732:
  
  
-== Create Foot Segments ==+=== Create Foot Segments ===
  
 To create the right shank segment: To create the right shank segment:
Line 780: 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 796: 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 811: 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 825: 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 835: 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 866: 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 884: 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 924: 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 930: 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 972: 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 1006: 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.1741019279.txt.gz · Last modified: 2025/03/03 16:27 by wikisysop