IOR Foot Model

This tutorial has been updated to match the naming convention used in the IOR foot paper. The original tutorial can be found here.
In 2014, updates to the IOR foot model were published. The updated tutorial can be found here.

Sample Data

Sample data can be downloaded here.

Once the zip file has been downloaded, you can find a static C3D and three dynamic trials in the SampleFiles folder. These files will be used to complete the tutorial.

The model, planar angles and joint angles for the right side were defined and plotted in the Leardini_2007_Angles.cmo. Once the left side angles have been defined, the report template will graph both the left and right angles.

Introduction

Visual3D is a general tool capable of implementing many different foot models.

This tutorial focuses on the multi-segment foot model as described in the following article:

Multi-Segment Foot Marker Set

Foot Targets

CA^[1] (FCC) ^[2] :p. 162 = Posterior Surface of Calcaneus ST^[1] (FST) ^[2] : p.164 = Sustentaculum Tali of Calcaneus PT^[1] (FPT) ^[2] : p.171 = Lateral apex of the peroneal tubercle TN^[1] (FNT) ^[2] : p.165 = Medial apex of the tuberosity navicular. FMH^[1] (FM1) ^[2] : p.173 = Head of 1st Metatarsus SMH^[1] (FM2) ^[2] : p.173 = Head of 2nd Metatarsus VMH^[1] (FM5) ^[2] : p.173 = Head of 5th Metatarsus VMB^[1] (FMT) ^[2] : p.172 = Tuberosity of 5th Metatarsal PM^[1] (PD6) ^[2] : p.175 = Proximal Distal Phalanx. * FMB^[1] = Base of First Metatarsal. ** SMB^[1] = Base of Second Metatarsal. **
* 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

HF^[1] (FAX) ^[2] : p.154 = Apex of the styloid process

TT^[1] (TTC) ^[2] : p.144 = Tibial tuberosity

LM^[1] (FAL) ^[2] : p.158 = Apex of the Lateral malleolus

MM^[1] (TAM) ^[2] : p.148 = Apex of the Medial malleolus

NOTE: This tutorial follows the naming convention presented in the IOR Foot paper.

Metatarsus (Met)

Landmarks

1. Create RMET_DIST:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RMET_DIST

Landmark Name: RMET_DIST

   Define Orientation Using:
   Starting Point: RFMH
   Ending Point: RVMH
   Lateral Object: RSMB
   Project From: RSMH

Do NOT Check: Offset by Percent (1.0 = 100%)

Check: Calibration Only Landmark

Segment 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
   Lateral: None     Joint: RSMB     Medial: None
   Radius: 0.1

   Define Distal Joint and Radius
   Lateral: None     Joint: RMET_DIST     Medial: None
   Radius: 0.1

Extra Target to Define Orientation
Location: Medial RFMH

Select Tracking Targets:
RFMB, RFMH, RSMB, RSMH, RVMB, RVMH

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
Distal to Proximal: -X

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)

Landmarks

1. Create RID Joint Center:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RID

Landmark Name: RID

   Define Orientation Using:
   Starting Point: RTN
   Ending Point: RVMB

Offset Using the Following AXIAL Offset: 0.5

Check: Offset by Percent (1.0 = 100%)

Check: Calibration Only Landmark

Segment 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
   Lateral: None     Joint: RID     Medial: None
   Radius: 0.1

   Define Distal Joint and Radius
   Lateral: None     Joint: RSMB     Medial: None
   Radius: 0.1

Extra Target to Define Orientation
Location: Medial RTN

Select Tracking Targets:
RSMB, RTN, RVMB

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
Distal to Proximal: -X

Calcaneus (Cal)

Landmarks

1. Create RIC Joint Center:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RIC

Landmark Name: RIC

   Define Orientation Using:
   Starting Point: RST
   Ending Point: RPT

Offset Using the Following AXIAL Offset: 0.5

Check: Offset by Percent (1.0 = 100%)

Check: Calibration Only Landmark

Segment Definition

1. Create RCal Segment:

In the Segments tab, select RCal in the Segment Name box.

Click on the Create Segment button.

In the RCal tab, enter these values:

   Define Proximal Joint and Radius
   Lateral: None     Joint: RCA     Medial: None
   Radius: 0.1

   Define Distal Joint and Radius
   Lateral: None     Joint: RIC     Medial: None
   Radius: 0.1

Extra Target to Define Orientation
Location: Medial RST

Select Tracking Targets:
RCA, RPT, RST

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
Distal to Proximal: -X

Foot (Foo)

Landmarks

1. Create RFT_DIST:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RFT_DIST

Landmark Name: RFT_DIST

   Define Orientation Using:
   Starting Point: RCA
   Ending Point: RFMH
   Lateral Object: RVMH
   Project From: RSMH

Do NOT Check: Offset by Percent (1.0 = 100%)

Check: Calibration Only Landmark

Segment Definition

1. Create Right Foot Segment:

In the Segments tab, select Right Foot in the Segment Name box.

Click on the Create Segment button.

In the Right Foot tab, enter these values:

   Define Proximal Joint and Radius
   Lateral: None     Joint: RCA     Medial: None
   Radius: 0.5*DISTANCE(RST,RPT)

   Define Distal Joint and Radius
   Lateral: None     Joint: RFT_DIST     Medial: None
   Radius: 0.5*DISTANCE(RFMH,RVMH)

Extra Target to Define Orientation
Location: Medial RFMH

Select Tracking Targets:
RCA, RFMH, RVMH

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
Distal to Proximal: -X

Shank (Sha)

Landmarks

1. Create RIM:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RIM

Landmark Name: RIM

   Define Orientation Using:
   Starting Point: RLM
   Ending Point: RMM

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:
   Starting Point: RIM
   Ending Point: RLM
   Lateral Object: RHF
   Project From: RTT

Do NOT Check: Offset by Percent (1.0 = 100%)

Check: Calibration Only Landmark

Segment 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
   Lateral: None     Joint: RSK_PROX     Medial: None
   Radius: DISTANCE(RSK_PROX,RHF)

   Define Distal Joint and Radius
   Lateral: None     Joint: RIM     Medial: None
   Radius: 0.5*DISTANCE(RLM,RMM)

Extra Target to Define Orientation
Location: Lateral RLM

Select Tracking Targets:
RHF, RLM, RMM, RTT

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
Distal to Proximal: +Y

Angles

Landmarks

The F2Pt and F2Ps planar angles are calculated as the angle between the lines created by the targets FMB-FMH and FMH-PM. To calculate this angle using the Compute Planar Angle command, an offset along the line between FMB and FMH is created to define the 3 point angle.

1. Create RF2P_Offset:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RF2P_Offset

Landmark Name: RF2P_Offset

   Define Orientation Using:
   Starting Point: RFMB
   Ending Point: RFMH

Offset Using the Following AXIAL Offset: 1.5

Check: Offset by Percent (1.0 = 100%)

Do NOT Check: Calibration Only Landmark

2. Create LF2P_Offset:

When defining the left signal, use same definitions as for the RF2P_Offset landmark

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.

3. 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:
X: 0.0 Y: 0.0 Z: 0.0

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 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:
X: 0.05 Y: 0.0 Z: 0.0

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))

5. 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:
X: 0.0 Y: 0.05 Z: 0.0

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))

6. Create RFMH_proj:

Click Landmarks button

Click Add New Landmark button

Create Landmark: RFMH_proj

Landmark Name: RFMH_proj

   Define Orientation Using:
   Starting Point: LAB_O
   Ending Point: LAB_X
   Lateral Object: LAB_Y
   Project From: RFMH

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:

7. RFMB
8. RSMH
9. RSMB
10. RVMH
11. RVMB

12. LFMH
13. LFMB
14. LSMH
15. LSMB
16. LVMH
17. LVMB

Planar Angles

F2Pt

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. Create RF2Pt planar angle:

Define Resulting Signal Name: RF2Pt

Calculate a 3 point angle between the following targets:

   1 - LANDMARK::ORIGINAL::RF2P_offset
   2 - TARGET::ORIGINAL::RFMH
   3 - TARGET::ORIGINAL::RPM
Angle Direction: Left Hand Rule
Use Range: -180 to 180 degrees
Projected onto Plane: XZ

Note: The reference segment will need to be changed to RMet within the text option.

2. Create LF2Pt 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.

S2F

S2F - the angle between the lines FMB-FMH and SMB-SMH projected onto the transverse plane of the metatarsus

1. Create RS2F planar angle:

Define Resulting Signal Name: RS2F

Calculate a 4 point angle between the following targets:

   1 - TARGET::ORIGINAL::RSMH
   2 - TARGET::ORIGINAL::RSMB
   3 - TARGET::ORIGINAL::RFMB
   4 - TARGET::ORIGINAL::RFMH
Angle Direction: Right Hand Rule
Use Range: -180 to 180 degrees
Projected onto Plane: XZ

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

S2V - the angle between the lines VMB-VMH and SMB-SMH projected onto the transverse plane of the metatarsus

1. Create RS2V planar angle:

Define Resulting Signal Name: RS2V

Calculate a 4 point angle between the following targets:

   1 - TARGET::ORIGINAL::RSMH
   2 - TARGET::ORIGINAL::RSMB
   3 - TARGET::ORIGINAL::RVMB
   4 - TARGET::ORIGINAL::RVMH
Angle Direction: Left Hand Rule
Use Range: -180 to 180 degrees
Projected onto Plane: XZ

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.

F2G

F2G - the angle between the lines FMB-FMH and the ground, plane orthogonal to the ground (3D angle relative to the ground)

The FMH_proj and FMB_proj landmarks will be used to calculate the F2G planar angle which are described in the landmarks section.

1. Create RF2G planar angle:

Define Resulting Signal Name: RF2G

Calculate a 4 point angle between the following targets:

   1 - TARGET::ORIGINAL::RFMB
   2 - TARGET::ORIGINAL::RFMH
   3 - TARGET::ORIGINAL::RFMH_proj
   4 - TARGET::ORIGINAL::RFMB_proj
Angle Direction: Right Hand Rule
3D Space: Always 0 to 180 degrees

2. Create LF2G planar angle:

When defining the left signal, use same definitions as for the right angle

S2G

S2G - the angle between the lines SMB-SMH and the ground, plane orthogonal to the ground (3D angle relative to the ground)

The SMH_proj and SMB_proj landmarks will be used to calculate the S2G planar angle which are described in the landmarks section.

1. Create RS2G planar angle:

Define Resulting Signal Name: RS2G

Calculate a 4 point angle between the following targets:

   1 - TARGET::ORIGINAL::RSMB
   2 - TARGET::ORIGINAL::RSMH
   3 - TARGET::ORIGINAL::RSMH_proj
   4 - TARGET::ORIGINAL::RSMB_proj
Angle Direction: Right Hand Rule
3D Space: Always 0 to 180 degrees

2. Create LS2G planar angle:

When defining the left signal, use same definitions as for the right angle

V2G

V2G - the angle between the lines VMB-VMH and the ground, plane orthogonal to the ground (3D angle relative to the ground)

The VMH_proj and VMB_proj landmarks will be used to calculate the V2G planar angle which are described in the landmarks section.

1. Create RV2G planar angle:

Define Resulting Signal Name: RV2G

Calculate a 4 point angle between the following targets:

   1 - TARGET::ORIGINAL::RVMB
   2 - TARGET::ORIGINAL::RVMH
   3 - TARGET::ORIGINAL::RVMH_proj
   4 - TARGET::ORIGINAL::RVMB_proj
Angle Direction: Right Hand Rule
3D Space: Always 0 to 180 degrees

2. Create LV2G planar angle:

When defining the left signal, use same definitions as for the right angle

F2Ps

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

1. Create RF2Ps planar angle:

Define Resulting Signal Name: RF2Ps

Calculate a 3 point angle between the following targets:

   1 - LANDMARK::ORIGINAL::RF2P_offset
   2 - TARGET::ORIGINAL::RFMH
   3 - TARGET::ORIGINAL::RPM
Angle Direction: Right Hand Rule
Use Range: -180 to 180 degrees
Projected onto Plane: XY

Note: The reference segment will need to be changed to RMet within the text option.

2. Create LF2Ps 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.

MLA

MLA - the angle between the lines CA-ST and ST-FMH projected onto the sagittal plane of the foot
Represents - navicular drop

1. Create RMLA planar angle:

Define Resulting Signal Name: RMLA

Calculate a 3 point angle between the following targets:

   1 - TARGET::ORIGINAL::RCA
   2 - TARGET::ORIGINAL::RST
   3 - TARGET::ORIGINAL::RFMH
Angle Direction: Right Hand Rule
Use Range: -180 to 180 degrees
Projected onto Plane: XY

Note: The reference segment will need to be changed to RMet within the text option.

2. Create LMLA 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.

Joint Angles

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 Foot
   Reference Segment: Right Shank
   Cardan Sequence: Z-X-Y

Use Negative:
X: TRUE Y: TRUE Z: FALSE

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
   Reference Segment: Right Shank
   Cardan Sequence: Z-X-Y

Use Negative:
X: TRUE Y: TRUE Z: FALSE

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
   Reference Segment: RCal
   Cardan Sequence: Z-X-Y

Use Negative:
X: TRUE Y: TRUE Z: FALSE

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
   Reference Segment: RMid
   Cardan Sequence: Z-X-Y

Use Negative:
X: TRUE Y: TRUE Z: FALSE

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
   Reference Segment: RCal
   Cardan Sequence: Z-X-Y

Use Negative:
X: TRUE Y: TRUE Z: FALSE

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 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 Serge van Sint Jan “Color Atlas of Skeletal Landmark Definitions: Guidelines for Reproducible Manual and Virtual Palpations” 2007 - Churchill Livingstone

Table of Contents

IOR Foot Model

Sample Data

Introduction

Multi-Segment Foot Marker Set

Foot Targets

Shank Targets

Metatarsus (Met)

Landmarks

Segment Definition

Mid-foot (Mid)

Landmarks

Segment Definition

Calcaneus (Cal)

Landmarks

Segment Definition

Foot (Foo)

Landmarks

Segment Definition

Shank (Sha)

Landmarks

Segment Definition

Angles

Landmarks

Planar Angles

F2Pt

S2F

S2V

F2G

S2G

V2G

F2Ps

MLA

Joint Angles

Sha_Foo_Angle

Sha_Cal_Angle

Cal_Mid_Angle

Mid_Met_Angle

Cal_Met_Angle

References