Foot Abnormality Mapping using Statistical Shape Modelling

NewsBot · Jan 20, 2017

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Foot Abnormality Mapping using Statistical Shape Modelling
Kristina STANKOVIĆ et al
Proceedings of the 7th International Conference on 3D Body Scanning Technologies, Lugano, Switzerland, 30 Nov.-1 Dec. 2016

About 20% of the population suffer from disabling foot or ankle pain that require the use of foot
orthotics. Traditionally, those foot orthotics are designed manually, but digital procedures are desired
to provide a faster, more objective, and more reliable workflow. In this study, we introduce a method
for detecting shape abnormalities in feet for the purposes of pathology diagnosis and orthotic design.
The proposed method consists of two phases. In the training phase, a statistical 3D foot model (based
on 42 healthy subjects) is built. In the test phase, the landmarks of a new 3D foot scan are compared
to the trained model. A landmark is detected as an outlier if it is in the extreme ranges. This testing
process is repeated at all landmarks to identify all abnormal foot regions. Preliminary results show
that, when testing a foot of a known pathology (hallux valgus, heel spur, foot pronation), we are able
to detect abnormal regions accurately. We also examined the effect of using rigid or similarity-based
alignment during 3D model building and abnormality detection. We show that our proposed method is
a faster and a more objective approach than traditional approaches for abnormality detection of the
foot. As such, this method may prove useful in the medical diagnosis of foot pathologies and in
automated orthotic design.
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NewsBot · Mar 11, 2018

Three-dimensional quantitative analysis of healthy foot shape: a proof of concept study
Kristina Stanković et al
Journal of Foot and Ankle Research201811:8

Background
Foot morphology has received increasing attention from both biomechanics researches and footwear manufacturers. Usually, the morphology of the foot is quantified by 2D footprints. However, footprint quantification ignores the foot’s vertical dimension and hence, does not allow accurate quantification of complex 3D foot shape.

Methods
The shape variation of healthy 3D feet in a population of 31 adult women and 31 adult men who live in Belgium was studied using geometric morphometric methods. The effect of different factors such as sex, age, shoe size, frequency of sport activity, Body Mass Index (BMI), foot asymmetry, and foot loading on foot shape was investigated. Correlation between these factors and foot shape was examined using multivariate linear regression.

Results
The complex nature of a foot’s 3D shape leads to high variability in healthy populations. After normalizing for scale, the major axes of variation in foot morphology are (in order of decreasing variance): arch height, combined ball width and inter-toe distance, global foot width, hallux bone orientation (valgus-varus), foot type (e.g. Egyptian, Greek), and midfoot width. These first six modes of variation capture 92.59% of the total shape variation. Higher BMI results in increased ankle width, Achilles tendon width, heel width and a thicker forefoot along the dorsoplantar axis. Age was found to be associated with heel width, Achilles tendon width, toe height and hallux orientation. A bigger shoe size was found to be associated with a narrow Achilles tendon, a hallux varus, a narrow heel, heel expansion along the posterior direction, and a lower arch compared to smaller shoe size. Sex was found to be associated with differences in ankle width, Achilles tendon width, and heel width. Frequency of sport activity was associated with Achilles tendon width and toe height.

Conclusion
A detailed analysis of the 3D foot shape, allowed by geometric morphometrics, provides insights in foot variations in three dimensions that can not be obtained from 2D footprints. These insights could be applied in various scientific disciplines, including orthotics and shoe design.
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NewsBot · Sep 7, 2021

Preventive strategy of flatfoot deformity using fully automated procedure
Che-Wei Hu et al
Med Eng Phys. 2021 Sep;95:15-24

A non-invasive, no radiation, out-of-hospital automated system is proposed to identify low arch integrated in the design and manufacturing of personalized orthoses using parametric modelling. The aim of the design process is to integrate assistive technology with assessment and prevent low arch progressing to a more serious case - flatfoot. In the automated procedure, we developed an assessment method including reliable thresholds of foot type classification and test protocol to reduce interferences due to preceding activities, an automation to translate scanned data into parametric design for orthotic customization, finite element model evaluating effectiveness of the personalized design, and a personalized comparative test to evaluate the long-term improvement of foot arch shape. Our low arch threshold established by subject-specific 3D models reduced the misclassification rate from 55%, as previously reported to 6.9%. Individuals who engaged in sedentary activity (i.e. sitting) had the greater change in arch height compared to active activity (i.e. standing and walking), which is more likely to affect the obtained measure. Therefore, a test protocol now states that participants are not allowed to sit over 100 min prior the measurement to reduce such interference. We have proposed and tested an automated algorithm to translate scanned data including seven foot's parameters into customised parametric design of the insert. The method decreases the required time of orthotic computer-aided design from over 3 h to less than 2 min. A finite element analysis procedure was additionally developed to assess the performance of geometries and material of designed orthotic based on the distribution of plantar pressure and internal stress. The personalized comparative assessment based on midfoot contact area was carried out periodically for follow-up and the orthotic could be re-designed if necessary. The proposed automated procedure develops a pre-screening system to distinguish low arch and provide preventatives before it becomes symptomatic. Furthermore, non-symptom flatfoot can be detected at early stages and referred to medics for further diagnosis or treatment.
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NewsBot · Feb 15, 2022

3D optical scanning as an objective and reliable tool for volumetry of the foot and ankle region
BenHofmann et al
Foot and Ankle Surgery; Volume 28, Issue 2, February 2022, Pages 200-204

Highlights
•Formation of foot and ankle edema is a well-known clinical problem.
•Ankle volume and the perimeter of the figure-of-eight are highly correlated.
•3D optical scanning allows contactless assessment of the foot and ankle volume.
•3D optical scanning turned out to be highly reliable.
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Background
Edema development of the foot and ankle region should be evaluated by an objective measurement. We hypothesized, that 3D optical scanning of this region can serve as an alternative to clinically established measurement techniques.

Methods
Two investigators determined the volume by 3D optical scanning and the figure-of-eight method in a random order at 2 separate time points. Plots were created and ICCs were calculated for determination of reliability. The Pearson correlation coefficient served as a measure of the association between both measures.

Results
40 healthy volunteers with mean age of 28.3 ± 9.9 years underwent four sequences of measurements. The inter- and intraobserver reliability of both methods was excellent with high intraclass correlation coefficients (ICC 3,1). A strong correlation (r = 0.96, P < 0.001) between measured ankle volumes was noted.

Conclusion
3D optical scanning turned out to be more reliable than the figure-of-eight method in a preclinical set-up. A clinical use should be aimed at.
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Foot Abnormality Mapping using Statistical Shape Modelling

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Foot Abnormality Mapping using Statistical Shape Modelling

NewsBot The Admin that posts the news.

NewsBot The Admin that posts the news.

NewsBot The Admin that posts the news.

NewsBot The Admin that posts the news.

Midfoot Joint Complex (Foot Arch) Contributes to the Upper Body Position in Bipedal Walking

Pravibismane for diabetic foot infections

Link Between the Foot and Cerebellum

Homeopathy for Diabetic Foot Ulcers

Foot crush injuries

Dysplasia epiphysealis hemimelica (Trevor's disease) in the foot and ankle

Diabetic Foot Influencers on Twitter

Share This Page

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