IORFoot Tutorial Angles

From Visual3D Wiki Documentation
Jump to: navigation, search
Language:  English  • français • italiano • português • español 

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

foot markersIOR 2014.png

CA[1] (FCP) [3] : p. 162 = Proximal posterior Surface of Calcaneus. *
HL[2] (FCD) [3] : p. 162 = Distal attachment of the Achilles' tendon. *
ST[1] (FST) [3] : p.164 = Sustentaculum Tali of Calcaneus.
PT[1] (FPT) [3] : p.171 = Lateral apex of the peroneal tubercle.
TN[1] (FNT) [3] : p.165 = Medial apex of the tuberosity navicular.
FMH[1] (FM1) [3] : p.173 = Head of 1st Metatarsus.
SMH[1] (FM2) [3] : p.173 = Head of 2nd Metatarsus.
VMH[1] (FM5) [3] : p.173 = Head of 5th Metatarsus.
VMB[1] (FMT) [3] : p.172 = Tuberosity of 5th Metatarsal
PM[1] (PD6) [3] : 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 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

HF[1] (FAX) [3] : p.154 = Apex of the styloid process
TT[1] (TTC) [3] : p.144 = Tibial tuberosity
LM[1] (FAL) [3] : p.158 = Apex of the Lateral malleolus
MM[1] (TAM) [3] : p.148 = Apex of the Medial malleolus

caption

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

caption

Hallux Landmarks

1. Create RHal_Vert:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RHal_Vert

       Landmark Name: RHal_Vert

       Define Orientation Using:
       Starting Point: RFMH
       Ending Point: RPM
       Lateral Object: RVMH

  4. Offset Using the Following ML/AP/AXIAL Offsets:
       X: 0.0    Y: -DISTANCE(RFMH,RPM)    Z: 0.0
  5. Do NOT Check: Offset by Percent (1.0 = 100%)
  6. Do NOT Check: Calibration Only Landmark

caption

Hallux Definition

1. Create RHal Segment:

  1. In the Segments tab, select RHal in the Segment Name box.
  2. Select Kinematic Only
  3. Click on the Create Segment button.
  4. In the RHal tab, enter these values:

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

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

       Extra Target to Define Orientation
       Location: Lateral     RHal_Vert

       Select Tracking Targets:
         RHal_Vert, RFMH, RPM

  5. Click on Build Model.
  6. Click on Close Tab before proceeding.

caption


2. Modify the Segment Coordinate System:

  1. Define the Segment Orientation as:

       A/P Axis: -Z
       Distal to Proximal: -X

caption

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

caption

Metatarsus Landmarks

1. Create RMET_DIST:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RMET_DIST

       Landmark Name: RMET_DIST

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

  4. Do NOT Check: Offset by Percent (1.0 = 100%)
  5. Check: Calibration Only Landmark

caption

Metatarsus Definition

1. Create RMet Segment:

  1. In the Segments tab, select RMet in the Segment Name box.
  2. Select Kinematic Only
  3. Click on the Create Segment button.
  4. 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, RVMH

  5. Click on Build Model.
  6. Click on Close Tab before proceeding.

caption


2. Modify the Segment Coordinate System:

  1. Define the Segment Orientation as:

       A/P Axis: +Y
       Distal to Proximal: -X

caption

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.

caption

Mid-foot Landmarks

1. Create RID Joint Center:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RID

       Landmark Name: RID

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

  4. Offset Using the Following AXIAL Offset: 0.5
  5. Check: Offset by Percent (1.0 = 100%)
  6. Check: Calibration Only Landmark

caption

Mid-foot Definition

1. Create RMid Segment:

  1. In the Segments tab, select RMid in the Segment Name box.
  2. Select Kinematic Only.
  3. Click on the Create Segment button.
  4. 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

  5. Click on Build Model.
  6. Click on Close Tab before proceeding.

caption


2. Modify the Segment Coordinate System:

  1. Define the Segment Orientation as:

       A/P Axis: +Y
       Distal to Proximal: -X

caption

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

caption

Calcaneus Landmarks

1. Create RIC Joint Center:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RIC

       Landmark Name: RIC

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

  4. Offset Using the Following AXIAL Offset: 0.5
  5. Check: Offset by Percent (1.0 = 100%)
  6. Check: Calibration Only Landmark

caption

Calcaneus Definition

1. Create RCal Segment:

  1. In the Segments tab, select RCal in the Segment Name box.
  2. Select Kinematic Only
  3. Click on the Create Segment button.
  4. In the RCal tab, enter these values:

       Define Proximal Joint and Radius
       Lateral: None     Joint: RFCP     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:
         RFCP, RPT, RST

  5. Click on Build Model.
  6. Click on Close Tab before proceeding.

caption


2. Modify the Segment Coordinate System:

  1. Define the Segment Orientation as:

       A/P Axis: +Y
       Distal to Proximal: -X

caption

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.

caption

Foot Landmarks

1. Create RFT_DIST:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RFT_DIST

       Landmark Name: RFT_DIST

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

  4. Do NOT Check: Offset by Percent (1.0 = 100%)
  5. Check: Calibration Only Landmark

caption

Foot Definition

1. Create Right Virtual Foot Segment:

  1. In the Segments tab, select Right Virtual Foot in the Segment Name box.
  2. Select Kinematic Only
  3. Click on the Create Segment button.
  4. In the Right Virtual Foot tab, enter these values:

       Define Proximal Joint and Radius
       Lateral: None     Joint: RFCP     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:
         RFCP, RFMH, RVMH

  5. Click on Build Model.
  6. Click on Close Tab before proceeding.

caption


2. Modify the Segment Coordinate System:

  1. Define the Segment Orientation as:

       A/P Axis: +Y
       Distal to Proximal: -X

caption

Shank (Sha)

Shank Landmarks

1. Create RIM:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RIM

       Landmark Name: RIM

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

  4. Offset Using the Following AXIAL Offset: 0.5
  5. Check: Offset by Percent (1.0 = 100%)
  6. Check: Calibration Only Landmark

caption

2. Create RSK_PROX:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RSK_PROX

       Landmark Name: RSK_PROX

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

  4. Do NOT Check: Offset by Percent (1.0 = 100%)
  5. Check: Calibration Only Landmark

caption

Shank Definition

1. Create Right Shank Segment:

  1. In the Segments tab, select Right Shank in the Segment Name box.
  2. Click on the Create Segment button.
  3. 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

  4. Click on Build Model.
  5. Click on Close Tab before proceeding.

caption


2. Modify the Segment Coordinate System:

  1. Define the Segment Orientation as:

       A/P Axis: +X
       Distal to Proximal: +Y

caption

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.

IORProjectionOutline.png

F2G S2G and V2G Landmarks

1. Create Lab_O:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: Lab_O

       Landmark Name: Lab_O

  4. Offset Using the Following ML/AP/AXIAL Offsets:
       X: 0.0    Y: 0.0    Z: 0.0
  5. Do NOT Check: Offset by Percent (1.0 = 100%) (Meters when not checked)
  6. Do NOT Check: Calibration Only Landmark (Not generated for assigned motion file(s))

caption


2. Create Lab_X:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: Lab_X

       Landmark Name: Lab_X

  4. Offset Using the Following ML/AP/AXIAL Offsets:
       X: 0.05    Y: 0.0    Z: 0.0
  5. Do NOT Check: Offset by Percent (1.0 = 100%) (Meters when not checked)
  6. Do NOT Check: Calibration Only Landmark (Not generated for assigned motion file(s))

caption


3. Create Lab_Y:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: Lab_Y

       Landmark Name: Lab_Y

  4. Offset Using the Following ML/AP/AXIAL Offsets:
       X: 0.0    Y: 0.05    Z: 0.0
  5. Do NOT Check: Offset by Percent (1.0 = 100%) (Meters when not checked)
  6. Do NOT Check: Calibration Only Landmark (Not generated for assigned motion file(s))

caption


4. Create RFMH_proj:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. 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

  4. Do NOT Check: Offset by Percent (1.0 = 100%)
  5. Do NOT Check: Calibration Only Landmark

caption


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

IOR F2GAngle.png

F2G Definition

1. Create RF2G planar angle:

  1. Define Resulting Signal Name: RF2G
  2. 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

PlanarAngle RF2G.png


2. Create LF2G planar angle:

  1. 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

IOR S2GAngle.png

S2G Definition

1. Create RS2G planar angle:

  1. Define Resulting Signal Name: RS2G
  2. 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

PlanarAngle RS2G.png


2. Create LS2G planar angle:

  1. 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

IOR V2GAngle.png


V2G Definition

1. Create RV2G planar angle:

  1. Define Resulting Signal Name: RV2G
  2. 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

PlanarAngle RV2G.png


2. Create LV2G planar angle:

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



MLA Angle

MLA Angle – MLA Angle – Medial Longitudinal Arch/Navicular drop

IOR MLAAngle.png

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:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RFCP_proj

       Landmark Name: RFCP_proj

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

  4. Do NOT Check: Offset by Percent (1.0 = 100%)
  5. Check: Calibration Only Landmark

caption

2. Create LFCP_proj:

  1. Use the same definition as the RFCP_proj, but use left side target

3. Create RFCP_proj_track:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RFCP_track

       Landmark Name: RFCP_proj_track

       Define Orientation Using:
       Starting Point: RFCP_proj
      Click Existing Segment: RCal

  4. Do NOT Check: Offset by Percent (1.0 = 100%)
  5. Do NOT Check: Calibration Only Landmark

caption

4. Create LFCP_proj_track:

  1. Use the same definition as the RFCP_proj_track, but use left side landmark/segment


MLA Definition

1. Create RMLA planar angle:

  1. Define Resulting Signal Name: RMLA
  2. Calculate a 3 point angle between the following targets:

       1 - LANDMARK::ORIGINAL::RFCP_track
       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 RMF within the text option.

    Command text should have the internal name (e.g. RMF) and not the display name "Right Virtual Foot".

    https://www.c-motion.com/v3dwiki/index.php?title=Segment_Default_Names

PlanarAngle RMLA 2014.png


2. Create LMLA planar angle:

  1. 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

IOR S2FAngle.png

S2F Definition

1. Create RS2F planar angle:

  1. Define Resulting Signal Name: RS2F
  2. 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.

PlanarAngle RS2F.png


2. Create LS2F planar angle:

  1. 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

IOR S2VAngle.png

S2V Definition

1. Create RS2V planar angle:

  1. Define Resulting Signal Name: RS2V
  2. 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.

PlanarAngle RS2V.png


2. Create LS2V planar angle:

  1. 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.

IOR Sha Cal FrontalAngle.png


Sha_Cal_Frontal Landmarks

1. Create RSK_PROX_track:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RSK_PROX_track

       Landmark Name: RSK_PROX_track

       Define Orientation Using:
      Click Existing Segment: RSK

  4. Offset Using the Following ML/AP/AXIAL Offsets:
       X: 0.0    Y: 0.0    Z: 0.0
  5. Check: Offset by Percent (1.0 = 100%)
  6. Do NOT Check: Calibration Only Landmark

caption

2. Create RSK_DIST_track:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RSK_DIST_track

       Landmark Name: RSK_DIST_track

       Define Orientation Using:
      Click Existing Segment: RSK

  4. Offset Using the Following ML/AP/AXIAL Offsets:
       X: 0.0    Y: 0.0    Z: -1.0
  5. Check: Offset by Percent (1.0 = 100%)
  6. Do NOT Check: Calibration Only Landmark

caption


3. Create RFCD_track Joint Center:

  1. Click Landmarks button
  2. Click Add New Landmark button
  3. Create Landmark: RFCD_track

       Landmark Name: RFCD_track

       Define Orientation Using:
      Click Existing Segment: RCal

  4. Offset to Existing Calibration Target or Landmark: RFCD
  5. Do NOT Check: Offset by Percent (1.0 = 100%)
  6. Do NOT Check: Calibration Only Landmark

caption

Sha_Cal_Frontal Definition

1. Create RSha_Cal_Fro planar angle:

  1. Define Resulting Signal Name: RSha_Cal_Fro
  2. Calculate a 4 point angle between the following targets:

       1 - LANDMARK::ORIGINAL::RSK_PROX_TRACK
       2 - LANDMARK::ORIGINAL::RSK_DIST_TRACK
       3 - LANDMARK::ORIGINAL::RFCD_TRACK
       4 - TARGET::ORIGINAL::RFCP
    Angle Direction: Left Hand Rule
    Use Range: -180 to 180 degrees
    Projected onto Plane: YZ

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

PlanarAngle RSha Cal Fro.png


2. Create LSha_Cal_Fro planar angle:

  1. 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:

  1. Open the Compute Model Based dialog
  2. Select JOINT_ANGLE from drop down list

       Data Name: RSha_Foo_Angle

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

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

caption

Sha_Cal_Angle

1. Define the RSha_Cal_Angle:

  1. Open the Compute Model Based dialog
  2. Select JOINT_ANGLE from drop down list

       Data Name: RSha_Cal_Angle

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

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

caption

Cal_Mid_Angle

1. Define the RCal_Mid_Angle:

  1. Open the Compute Model Based dialog
  2. Select JOINT_ANGLE from drop down list

       Data Name: RCal_Mid_Angle

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

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

caption

Mid_Met_Angle

1. Define the RMid_Met_Angle:

  1. Open the Compute Model Based dialog
  2. Select JOINT_ANGLE from drop down list

       Data Name: RMid_Met_Angle

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

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

caption

Cal_Met_Angle


1. Define the RCal_Met_Angle:

  1. Open the Compute Model Based dialog
  2. Select JOINT_ANGLE from drop down list

       Data Name: RCal_Met_Angle

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

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

caption

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:

  1. Open the Compute Model Based dialog
  2. Select JOINT_ANGLE from drop down list

       Data Name: RMet_Hal_Angle

       Segment: RHal
       Reference Segment: RMet
       Cardan Sequence: Z-X-Y

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

caption

References

  1. 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. 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)
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 3.13 3.14 3.15 Serge van Sint Jan "Color Atlas of Skeletal Landmark Definitions: Guidelines for Reproducible Manual and Virtual Palpations" 2007 - Churchill Livingstone
Retrieved from ""