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Table of Contents
IORFoot Tutorial Angles
Introduction
The IOR Foot analysis uses joint angles and planar angles to describe the motion of the foot.
****
The IOR Foot analysis has been described in the paper:
****
Leardini, A., M.G. Benedetti, L. Berti, D. Bettinelli, R. Nativo, and S. Giannini. “Rear-foot, Mid-foot and Fore-foot Motion during the Stance Phase of Gait.” Gait & Posture 25 (2007): 453-55 [1]
**** Modifications to the IOR Foot Analysis are described in the paper:
****
Portinaro, N., A. Leardini, A. Panou, V. Monzani, and P. Caravaggi. “Modifying the Rizzoli foot model to improve the diagnosis of pes-planus: application to kinematics of feet in teenagers.” Journal of Foot and Ankle Research (2014) [2]
**** This tutorial describes the original analysis with all modifications from the 2014 paper.
****
The 2007 paper is described here.
Downloads
Sample data for this tutorial can be downloaded here.
The PPT images shown in this tutorial can be downloaded here.
Modifications
Three modifications were made between the first[1] and second[2] papers. These modifications are outlined below.
Mod 1: Hallux
Previously, varus & dorsiflexion at the first metatarso-phalangeal joint were represented by planar angles (F2Pt and F2Ps)[1].
The 2014 paper creates a hallux segment and calculates the F2Pt and F2Ps angles as joint angles between the Hallux & Metatarsus segments[2].
Mod 2: Calcaneus
The original paper [1] only contained one target on the posterior calcaneus. The 2014 modifications[2] contain two targets on the posterior calcaneus.
The 2007 paper[1] described the CA target as the:
CA - upper central ridge of the calcaneus posterior surface, i.e. Achilles' tendon attachment
The 2014 paper[2] described the HL target as the:
HL - most distal point of attachment area of the Achilles tendon on the calcaneus
The CA[1] target will be referred to as the FCP (calcaneus proximal - the proximal attachement of the tendon) for the remainder of this tutorial.
The HL[2] target will be referred to as the FCD (calcaneus distal - FCC[3] [pg. 162]) for the remainder of this tutorial.
The FCP target will be used to indicate the origin of the calcaneus segment, and the orientation of the FCP/FCD targets will be used to indicate inversion/eversion of the calcaneus (Sha_Cal_Fro Angle). When placing these targets, make sure there is enough distance between them so that your camera system can recognize them as two separate targets.
The FCD target should be removed after the static trial.
Mod 3: MLA Angle
Previously, the MLA angle was calculated using the CA target[1].
The 2014 paper projects the FCP target onto the ground during the static trial (FCP_proj), and tracks this projection using the calcaneus segment (FCP_proj_track)[2].
Target Placement
The following text contains a detailed explanation of how to palpate the necessary bony landmarks:
Serge van Sint Jan “Color Atlas of Skeletal Landmark Definitions: Guidelines for Reproducible Manual and Virtual Palpations” 2007 - Churchill Livingstone [3]
Foot Targets
* Serge Van Sint Jan describes palpation for the FCC landmark (which should be the FCD), and the FCP landmark should be placed proximal to this landmark.
** Serge Van Sint Jan describes palpation for the mediolateral borders of this landmark (PM6/PL6), the target should be placed at the midpoint.
*** There is no reference for this landmark in Serge Van Sint Jan text, please see the IOR Foot paper for further clarification
Shank Targets
Segment Definition
Hallux (Hal)
| Segment Definition: The FMH target is defined as the origin of Hal segment. The A/P (X) axis is defined from the FMH to PM target. The sagittal axis (Z axis) is along the plane defined by the FMH, FM, and VMH targets. The Hal segment is a modification[2] to the original analysis[1] Joint Angles: * F2Pt[1]/ Y component of the Met-Hal Angle[2] * F2Ps[1]/ Z component of the Met-Hal Angle[2] Planar Angles: * No planar angles |  |
| Hallux Landmarks | |||||
| 1. Create RHal_Vert:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RHal_Vert |
Offset Using the Following ML/AP/AXIAL Offsets:
Do NOT Check: Offset by Percent (1.0 = 100%)
Do NOT Check: Calibration Only Landmark |  |
|||
| Hallux Definition | ||||||||||||
| 1. Create RHal Segment:
In the Segments tab, select RHal in the Segment Name box.
Select Kinematic Only
Click on the Create Segment button.
In the RHal tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Extra Target to Define Orientation
Select Tracking Targets: |
Click on Build Model.
Click on Close Tab before proceeding. |  | 2. Modify the Segment Coordinate System:
Define the Segment Orientation as: |
A/P Axis: -Z |  | The image to the right (and all other images in this tutorial) show a mediolateral view of the segment coordinate system after it has been modified. |
|||||
Metatarsus (Met)
| Segment Definition: The FM2 landmark is projected onto the plane defined by the FM1, FM5, and SMB landmarks. The line from the SMB to FM2 projection are used to define the X axis (A/P) axis of the Met segment. The sagittal axis (Z axis) is along the plane defined by the FM1, FM5, and SMB targets. The FMB target is not used to define the segment, but it will be used to track the segment (in addition to the other targets). Joint Angles: * Mid-Met Angle * Cal-Met Angle * F2Pt[1]/ Y component of the Met-Hal Angle[2] * F2Ps[1]/ Z component of the Met-Hal Angle[2] Planar Angles: * S2F is projected onto the plane of the Met segment * S2V is projected onto the plane of the Met segment |  |
| Metatarsus Landmarks | ||||||
| 1. Create RMET_DIST:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RMET_DIST |
Landmark Name: RMET_DIST
Define Orientation Using: |
Do NOT Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  |
|||
| Metatarsus Definition | ||||||||||||
| 1. Create RMet Segment:
In the Segments tab, select RMet in the Segment Name box.
Select Kinematic Only
Click on the Create Segment button.
In the RMet tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Extra Target to Define Orientation
Select Tracking Targets: |
Click on Build Model.
Click on Close Tab before proceeding. |  | 2. Modify the Segment Coordinate System:
Define the Segment Orientation as: |
A/P Axis: +Y |  | The image to the right (and all other images in this tutorial) show a mediolateral view of the segment coordinate system after it has been modified. |
|||||
Mid-foot (Mid)
| Segment Definition: The midpoint between the TN and VMB targets is used to define the origin of the Mid segment. The A/P (X) axis is defined along the line from this midpoint to the SMB target. The sagittal (Z) axis is along the plane defined by the ID, TN and SMB targets. Joint Angles: * Cal-Mid Angle * Mid-Met Angle Planar Angles: * Not used for planar angles. |  |
| Mid-foot Landmarks | ||||||
| 1. Create RID Joint Center:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RID |
Landmark Name: RID
Define Orientation Using: |
Offset Using the Following AXIAL Offset: 0.5
Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  |
|||
| Mid-foot Definition | ||||||||||||
| 1. Create RMid Segment:
In the Segments tab, select RMid in the Segment Name box.
Select Kinematic Only.
Click on the Create Segment button.
In the RMid tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Extra Target to Define Orientation
Select Tracking Targets: |
Click on Build Model.
Click on Close Tab before proceeding. |  | 2. Modify the Segment Coordinate System:
Define the Segment Orientation as: |
A/P Axis: +Y |  |
||||||
Calcaneus (Cal)
| Segment Definition: The origin is at the FCP target. The A/P (X) axis is along the line from the FCP to midpoint of the ST and PT targets (IC landmark). The sagittal (Z) axis is along the plane defined by the FCP, ST and TN targets. Joint Angles: * Sha-Cal Angle * Cal-Mid Angle Z rotation & Y Rotation* * Cal-Met Angle * The 2014 paper[2] modified the definition of inversion/eversion for the calcaneus segment relative to the shank segment. This is now calculated as the Sha_Cal_Fro angle which is a four point planar angle. Planar Angles: * No planar angles |  |
| Calcaneus Landmarks | ||||||
| 1. Create RIC Joint Center:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RIC |
Landmark Name: RIC
Define Orientation Using: |
Offset Using the Following AXIAL Offset: 0.5
Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  |
|||
| Calcaneus Definition | ||||||||||||
| 1. Create RCal Segment:
In the Segments tab, select RCal in the Segment Name box.
Select Kinematic Only
Click on the Create Segment button.
In the RCal tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Extra Target to Define Orientation
Select Tracking Targets: |
Click on Build Model.
Click on Close Tab before proceeding. |  | 2. Modify the Segment Coordinate System:
Define the Segment Orientation as: |
A/P Axis: +Y |  |
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Virtual Foot (Foo)
| Segment Definition: The origin is at the FCP target. The A/P (X) axis is along the line from the FCP to RFT_DIST landmark. The sagittal (Z) axis is along the plane defined by the FCP, FMH and VMH targets. This foot segment should be set to “kinematic only” since the origin is not at the point of rotation (the mid point of the RIMM & RLM targets. The IORFoot analysis does not calculate kinetics, so no kinetic foot segment is described in this model. To create gait events, you will need a kinetic foot segment. An example of a kinetic foot segment is created in the sample download files for this tutorial. |  |
| Foot Landmarks | ||||||
| 1. Create RFT_DIST:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RFT_DIST |
Landmark Name: RFT_DIST
Define Orientation Using: |
Do NOT Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  |
|||
| Foot Definition | ||||||||||||
| 1. Create Right Virtual Foot Segment:
In the Segments tab, select Right Virtual Foot in the Segment Name box.
Select Kinematic Only
Click on the Create Segment button.
In the Right Virtual Foot tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Extra Target to Define Orientation
Select Tracking Targets: |
Click on Build Model.
Click on Close Tab before proceeding. |  | 2. Modify the Segment Coordinate System:
Define the Segment Orientation as: |
A/P Axis: +Y |  |
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Shank (Sha)
| Shank Landmarks | ||||||||||||
| 1. Create RIM:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RIM |
Landmark Name: RIM
Define Orientation Using: |
Offset Using the Following AXIAL Offset: 0.5
Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  | 2. Create RSK_PROX:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RSK_PROX |
Landmark Name: RSK_PROX
Define Orientation Using: |
Do NOT Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  |
|||||
| Shank Definition | ||||||||||||
| 1. Create Right Shank Segment:
In the Segments tab, select Right Shank in the Segment Name box.
Click on the Create Segment button.
In the Right Shank tab, enter these values: |
Define Proximal Joint and Radius
Define Distal Joint and Radius
Extra Target to Define Orientation
Select Tracking Targets: |
Click on Build Model.
Click on Close Tab before proceeding. |  | 2. Modify the Segment Coordinate System:
Define the Segment Orientation as: |
A/P Axis: +X |  |
||||||
Sagittal Planar Angles
The F2G, S2G, and V2G angles are planar angles relative to the ground.
The MLA angle is the angle between the Medial Longitudinal Arch/Navicular drop.
F2G S2G and V2G Landmarks
| The F2G, S2G and V2G angles are calculated in the plane orthogonal to the ground. These landmarks will need to be projected onto the ground. To project landmarks onto the ground, the Lab_O, Lab_X and Lab_Y landmarks will need to be created to identify the plane of the ground. |  |
| F2G S2G and V2G Landmarks | |||||||||||||||||||||||||||
| 1. Create Lab_O:
Click Landmarks button
Click Add New Landmark button
Create Landmark: Lab_O |
Landmark Name: Lab_O |
Offset Using the Following ML/AP/AXIAL Offsets:
Do NOT Check: Offset by Percent (1.0 = 100%) (Meters when not checked)
Do NOT Check: Calibration Only Landmark (Not generated for assigned motion file(s)) |  | 2. Create Lab_X:
Click Landmarks button
Click Add New Landmark button
Create Landmark: Lab_X |
Landmark Name: Lab_X |
Offset Using the Following ML/AP/AXIAL Offsets:
Do NOT Check: Offset by Percent (1.0 = 100%) (Meters when not checked)
Do NOT Check: Calibration Only Landmark (Not generated for assigned motion file(s)) |  | 3. Create Lab_Y:
Click Landmarks button
Click Add New Landmark button
Create Landmark: Lab_Y |
Landmark Name: Lab_Y |
Offset Using the Following ML/AP/AXIAL Offsets:
Do NOT Check: Offset by Percent (1.0 = 100%) (Meters when not checked)
Do NOT Check: Calibration Only Landmark (Not generated for assigned motion file(s)) |  | 4. Create RFMH_proj:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RFMH_proj |
Landmark Name: RFMH_proj
Define Orientation Using: |
Do NOT Check: Offset by Percent (1.0 = 100%)
Do NOT Check: Calibration Only Landmark |  | Create landmarks 7-17 by following the same format as the RFMH_proj landmark for: ** ** | 5. RFMB 6. RSMH 7. RSMB 8. RVMH 9. RVMB | 10. LFMH 11. LFMB 12. LSMH 13. LSMB 14. LVMH 15. LVMB | **** |
||||||||
F2G Angle
| F2G Angle – 3D angle of the first metatarsus relative to the ground |  |
| F2G Definition | ||||||||||
| 1. Create RF2G planar angle:
Define Resulting Signal Name: RF2G
Calculate a 4 point angle between the following targets: |
1 - TARGET::ORIGINAL::RFMB |  | 2. Create LF2G planar angle:
When defining the left signal, use same definitions as for the right angle |
| ||||||
S2G Angle
| S2G Angle – 3D angle of the second metatarsus relative to the ground |  |
| S2G Definition | ||||||||||
| 1. Create RS2G planar angle:
Define Resulting Signal Name: RS2G
Calculate a 4 point angle between the following targets: |
1 - TARGET::ORIGINAL::RSMB |  | 2. Create LS2G planar angle:
When defining the left signal, use same definitions as for the right angle |
| ||||||
V2G Angle
| V2G Angle – 3D angle of the fifth metatarsus relative to the ground |  |
| V2G Definition | ||||||||||
| 1. Create RV2G planar angle:
Define Resulting Signal Name: RV2G
Calculate a 4 point angle between the following targets: |
1 - TARGET::ORIGINAL::RVMB |  | 2. Create LV2G planar angle:
When defining the left signal, use same definitions as for the right angle |
| ||||||
MLA Angle
| MLA Angle – MLA Angle – Medial Longitudinal Arch/Navicular drop |  |
| MLA Angle Landmarks | |||||||||||||||||||||
| The MLA angle is calculated using the proximal heel target projected onto the ground, tracked using the calcaneus segment. To accomplish this, two landmarks must be created: 1. The projection of the proximal heel target onto the ground 2. Track the proximal heel target projection using the calcaneus segment To create these landmarks, the LAB_O, LAB_X and LAB_Y landmarks must be created and the calcaneus segment must be defined. | NOTE: The image for the MLA Angle shows the PROCESSED target folder being used for the signal definition. If you have used the ORIGINAL target data for the other planar angles, you should continue to use the ORIGINAL folder. | 1. Create RFCP_proj:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RFCP_proj |
Landmark Name: RFCP_proj
Define Orientation Using: |
Do NOT Check: Offset by Percent (1.0 = 100%)
Check: Calibration Only Landmark |  | 2. Create LFCP_proj: - Use the same definition as the RFCP_proj, but use left side target | 3. Create RFCP_proj_track:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RFCP_track |
Landmark Name: RFCP_proj_track
Define Orientation Using: |
Do NOT Check: Offset by Percent (1.0 = 100%)
Do NOT Check: Calibration Only Landmark |  | 4. Create LFCP_proj_track: - Use the same definition as the RFCP_proj_track, but use left side landmark/segment | ||||||||||
| MLA Definition | ||||||||||
| 1. Create RMLA planar angle:
Define Resulting Signal Name: RMLA
Calculate a 3 point angle between the following targets: |
1 - LANDMARK::ORIGINAL::RFCP_track
Note: The reference segment will need to be changed to RMF within the text option.
https:%%//%%www.c-motion.com/v3dwiki/index.php?title=Segment_Default_Names |  | 2. Create LMLA planar angle:
When defining the left signal, use same definitions as for the right angle |
Note: The reference segment will need to be changed to Left Virtual Foot within the text option. | ||||||
Transverse Planar Angles
S2F Angle
| S2F Angle – Angle between the first and second metatarsus projected on to the transverse plane of the Met segment |  |
| S2F Definition | ||||||||||
| 1. Create RS2F planar angle:
Define Resulting Signal Name: RS2F
Calculate a 4 point angle between the following targets: |
1 - TARGET::ORIGINAL::RSMH
Note: The reference segment will need to be changed to RMet within the text option. |  | 2. Create LS2F planar angle:
When defining the left signal, use same definitions except set: |
Angle Direction: Left Hand Rule
Note: The reference segment will need to be changed to LMet within the text option. | ||||||
S2V Angle
| S2V Angle – Angle between the fifth and second metatarsus projected on to the transverse plane of the Met segment |  |
| S2V Definition | ||||||||||
| 1. Create RS2V planar angle:
Define Resulting Signal Name: RS2V
Calculate a 4 point angle between the following targets: |
1 - TARGET::ORIGINAL::RSMH
Note: The reference segment will need to be changed to RMet within the text option. |  | 2. Create LS2V planar angle:
When defining the left signal, use same definitions except set: |
Angle Direction: Right Hand Rule
Note: The reference segment will need to be changed to LMet within the text option. | ||||||
Calcaneus Inv/Eve
| Sha_Cal_Frontal Angle – Angle of the calcaneus segment relative to the shank segment This planar angle will be used to replace the inversion/eversion angle of the Sha_Cal joint angle 0 degrees indicates the calcaneus is aligned with the shank. |  |
| Sha_Cal_Frontal Landmarks | ||||||||||||||||||
| 1. Create RSK_PROX_track:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RSK_PROX_track |
Landmark Name: RSK_PROX_track
Define Orientation Using: |
Offset Using the Following ML/AP/AXIAL Offsets:
Check: Offset by Percent (1.0 = 100%)
Do NOT Check: Calibration Only Landmark |  | 2. Create RSK_DIST_track:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RSK_DIST_track |
Landmark Name: RSK_DIST_track
Define Orientation Using: |
Offset Using the Following ML/AP/AXIAL Offsets:
Check: Offset by Percent (1.0 = 100%)
Do NOT Check: Calibration Only Landmark |  | 3. Create RFCD_track Joint Center:
Click Landmarks button
Click Add New Landmark button
Create Landmark: RFCD_track |
Landmark Name: RFCD_track
Define Orientation Using: |
Offset to Existing Calibration Target or Landmark: RFCD
Do NOT Check: Offset by Percent (1.0 = 100%)
Do NOT Check: Calibration Only Landmark |  |
|||||||
| Sha_Cal_Frontal Definition | ||||||||||
| 1. Create RSha_Cal_Fro planar angle:
Define Resulting Signal Name: RSha_Cal_Fro
Calculate a 4 point angle between the following targets: |
1 - LANDMARK::ORIGINAL::RSK_PROX_TRACK
Note: The reference segment will need to be changed to RSK within the text option. |  | 2. Create LSha_Cal_Fro planar angle:
When defining the left signal, use same definitions except set: |
Angle Direction: Right Hand Rule
Note: The reference segment will need to be changed to LSK within the text option. | ||||||
Joint Angles
Joint Angle definitions for the:
- Sha_Foo_Angle
- Sha_Cal_Angle
- Cal_Mid_Angle
- Mid_Met_Angle
- Cal_Met_Angle
- Met_Hal_Angle
The Met_Hal_Angle calculations are used to replace the F2Ps & F2Pt planar angles from the 2007 paper[1].
| Joint Angle Definitions | ||||||||||||||||||||||||||||||||||||
| Sha_Foo_Angle | 1. Define the RSha_Foo_Angle:
Open the Compute Model Based dialog
Select JOINT_ANGLE from drop down list |
Data Name: RSha_Foo_Angle
Segment: Right Virtual Foot |
Use Negative: |  | Sha_Cal_Angle | 1. Define the RSha_Cal_Angle:
Open the Compute Model Based dialog
Select JOINT_ANGLE from drop down list |
Data Name: RSha_Cal_Angle
Segment: RCal |
Use Negative: |  | Cal_Mid_Angle | 1. Define the RCal_Mid_Angle:
Open the Compute Model Based dialog
Select JOINT_ANGLE from drop down list |
Data Name: RCal_Mid_Angle
Segment: RMid |
Use Negative: |  | Mid_Met_Angle | 1. Define the RMid_Met_Angle:
Open the Compute Model Based dialog
Select JOINT_ANGLE from drop down list |
Data Name: RMid_Met_Angle
Segment: RMet |
Use Negative: |  | Cal_Met_Angle | 1. Define the RCal_Met_Angle:
Open the Compute Model Based dialog
Select JOINT_ANGLE from drop down list |
Data Name: RCal_Met_Angle
Segment: RMet |
Use Negative: |  | Met_Hal_Angle The Met_Hal angle is the angle of the hallux relative to the metarsus segment. This sagittal and transverse angles of the Met_Hal_Angle angles create the F2Ps & F2Pt planar angles from the 2007 paper[1]. Since the targets used to track this segment are nearly colinear, useful information cannot be calculated from rotations in the coronal plane. F2Ps - the angle between the lines FMH-PM and FMB-FMH projected onto the sagittal plane of the metatarsus Represents - dorsiflexion of the first metatarso-phalangeal joint F2Pt - the angle between the lines FMH-PM and FMB-FMH projected onto the transverse plane of the metatarsus Represents - valgus of the first metatarsophalangeal joint | 1. Define the RMet_Hal_Angle:
Open the Compute Model Based dialog
Select JOINT_ANGLE from drop down list |
Data Name: RMet_Hal_Angle
Segment: RHal |
Use Negative: |  |
|||||||
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 Leardini, A., M.G. Benedetti, L. Berti, D. Bettinelli, R. Nativo, and S. Giannini. “Rear-foot, Mid-foot and Fore-foot Motion during the Stance Phase of Gait.” Gait & Posture 25 (2007): 453-55
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 Portinaro, N., A. Leardini, A. Panou, V. Monzani, and P. Caravaggi. “Modifying the Rizzoli foot model to improve the diagnosis of pes-planus: application to kinematics of feet in teenagers.” Journal of Foot and Ankle Research (2014)
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- This page was last edited on 9 November 2018, at 15:09.
