Repeatability of a multi-segment foot model

with a 15-marker set in healthy children

Eo Jin Kim, MD1, Dong Yeon Lee, MD2,,Doo Jae Lee, MD2, Seong Hyun Kim, BS2, Hyo Jung Yoo, BS2, Won Jun Yoo, MD2, In Ho Choi, MD2

1Dept. of Orthopedic Surgery, Hanil General Hospital, Korea2Dept. of Orthopedic Surgery, Seoul National University Hospital, Korea

NO CONFLICT TO DISCLOSE

Repeatability of a multi-segment foot model with a

15-marker set in healthy children

Eo Jin Kim, MD, Dong Yeon Lee, MD, Doo Jae Lee, MD, Seong Hyun Kim, Hyo Jung Yoo, Won Jun Yoo, MD,

In Ho Choi, MD

Our disclosure is in the Final AOFAS Mobile App.

I have no potential conflicts with this presentation.

Introduction

• 3D multi-segment foot models (3D MFMs)

- Analysis of dynamic foot kinematics for diagnosis and

treatment

• 3D MFM using a 15 marker set

- Demonstrated intra-session and inter-session repeatability

comparable with other MFMs in the assessment of foot

motion in healthy adults

• Purpose

- To determine the reliability of the 3D MFM with a 15-

marker set in normal children

Material & Methods

• 40 feet of twenty healthy children

- 10 males, 10 females

- Age : 10-12 yrs

Group A (N=10) Group B (N=10)

1st visit 2nd visit 1st visit 2nd visit

Marker

placement

Operator A

(N=5)4wks

later

Operator A

(N=5)

Operator A

(N=5)4wks

later

Operator B

(N=5)

Operator B

(N=5)

Operator B

(N=5)

Operator B

(N=5)

Operator A

(N=5)

3D MFM using a 15 marker set

• Motion capture & analysis (Motion Analysis Co.)

-12 CCD cameras with a 3D optical motion system

- Eva Real-Time software

- Foot 3D Multi-Segment Software

• Coefficients of Multiple Correlation (CMC) and

Intra-Class Correlation (ICC) were calculated.

Results

• Repeatability of foot kinematics

Distance Map

Talar Navicular

Intra-session CMC Inter-session CMC Inter-rater CMC

Present study Healthy adults6 Present study Healthy adults6 Present study

HalluxFlex/Ext 0.962 0.971 0.859 0.796 0.880

Rot 0.874 0.970 0.955 0.951 0.746

Hind

Foot

Flex/Ext 0.913 0.931 0.923 0.837 0.913Pro/Sup 0.858 0.890 0.842 0.697 0.664

Rot 0.892 0.927 0.371 0.728 0.623

Arch

Height 0.954 0.959 0.788 0.798 0.862Length 0.980 0.909 0.975 0.980 0.971Index* 0.950 0.952 0.797 0.729 0.851

Fore

foot

Flex/Ext 0.956 0.978 0.943 0.840 0.888Pro/Sup 0.786 0.993 0.748 0.687 0.482

Rot 0.901 0.972 0.726 0.813 0.724

*Arch index = Arch height / Arch length

Results

• Difference of two sessions

Distance Map

Talar Navicular

Gap (mean)Standard error Range

Present study Healthy adults6

HalluxFlex/Ext 3.99 4.0 0.12 (1.65, 6.53)

Rot 2.58 3.6 0.06 (0.72, 8.07)

Hind

Foot

Flex/Ext 2.55 1.3 0.05 (1.32, 3.92)

Pro/Sup 3.85 4.3 0.04 (0.86, 10.22)

Rot 6.51 3.0 0.10 (1.31, 11.32)

Arch

Height 5.84 4.9 0.05 (0.41, 14.25)

Length 1.85 2.0 0.03 (0.57, 6.31)

Index* 0.03 0.03 0.00 (0.00, 0.08)

Fore

foot

Flex/Ext 2.26 2.6 0.04 (0.94, 4.95)

Pro/Sup 3.51 3.0 0.06 (1.39, 9.75)

Rot 4.27 3.9 0.09 (2.20, 7.53)

*Arch index = Arch height / Arch length

Comparison between 1st and 2nd visit

Discussion

• Inter-session CMC of hindfoot rotation, Inter-rater

CMC of hindfoot pronation/supination, rotation

and forefoot pronation/supination has significantly

lower CMC values.

• Considering lower repeatability in hindfoot

rotation and pronation/supination, hindfoot

markers would be the most critical markers for

reliability of foot motion analysis in children.

Conclusion

• The intra-session and inter-session repeatability of

3D Foot system in children were comparable to

those in healthy adults except hindfoot parameters.

• We think that 3D MFM using a 15 marker set might

be used for evaluation of inter-segemental foot

motion in children, with caution in interpretation

of hindfoot foot parameters.

References1. Stebbins, J. et al. (2006) Repeatability of a model for measuring multi-segment

foot kinematics in children. Gait & Posture, 23(4):401-10.

2. Carson, MC. et al. (2001) Kinematic analysis of a multi-segment foot model for

research and clinical applications: a repeatability analysis. Journal of Biomech,

34(10):1299-307.

3. Kidder, SM. et al. (1996) A system for the analysis of foot and ankle kinematics

during gait. IEEE Transactions on Rehabilitation Engineering, 4(1):25-32.

4. Henley, J. et al. (2008) Reliability of a clinically practical multisegment foot marker

set/model. Boca Raton, pp. 445–63.

5. Bruening, DA. et al. (2012) Analysis of a kinetic multi-segment foot model. Part I:

Model repeatability and kinematic validity. Gait & Posture, 35(4):529-34

6. Seo, SG. et al. (2014) Repeatability of a multi-segment foot model with a 15-

marker set in healthy adults Journal of foot and ankle research, 7:24.