Taiwanese adult foot shape classification using 3D scanning data

3D human ear modelling with parameterization technique and variation analysis

Anthropometry is vital to provide design references when seeking proper product fit. Nowadays, 3D anthropometry is widely used to provide more size and shape details for improving product designs. However, 3D ear anthropometry is still at an explorative stage, considering the complex ear morphology and other technical obstacles. The proposed research method in this study is applicable to analyse the 3D point cloud of the entire external ear. With the cross-parameterisation technique, the dataset was used to explore the morphological characteristics of the ear. Ear dimensions were automatically extracted and further analysed to explore the gender and symmetry differences using two-way ANOVA. The 3D ear models were investigated through Principal Component Analysis (PCA). The most significant variation was found in the helix and concha region, and the overall ear size is the second important factor determining ear variance. The statistical models were generated as 3D design references for ear-related products.Practitioner summary: This study revealed the morphological variations of the entire 3D external ear with a parameterised 3D ear dataset. Based on the PCA findings, a set of statistical models were generated as design references for product evaluation digitally or physically.

Do foot type classifications differ between male and female netball players? A cluster analysis

We must better understand the foot type classifications of netball players to develop sex and size-specific shoe lasts. Five hundred and two representative-level netball players (n = 251 male; n = 251 female) had their feet three-dimensionally scanned. A validated MATLAB code was used to extract six different foot measurements from these scans automatically. We then used a two-step cluster analysis and chi-squared tests to classify foot types and determine the effect of sex on each cluster, respectively. Five foot types were identified (Extra long-and-wide, Long-and-wide, Flat, Tapered and Short-and-narrow), with sex significantly affecting foot type classification. The feet of players wearing smaller shoe sizes were often Short-and-narrow and Tapered, whereas the feet of players wearing larger sizes tended to be more Extra long-and-wide and Long-and-wide. These results highlight that netball players have a wide variety of foot types; manufacturers should use these data to develop future grading systems to improve the fit and functionality of netball-specific footwear.

Exploring flatfeet morphology in children aged 6-12 years: relationships with body mass and body height through footprints and three-dimensional measurements

The aim of the study was to determine the relationship between flatfoot morphology and body mass and height in children aged 6-12 years. A total of 6471 Chinese children (mean age 9.0 ± 1.9 years, 41% female) were assessed for foot morphometry, body height, and body mass index. Foot morphology, including foot length, width, girth, arch height, hallux valgus angle, and rearfoot valgus angle, was measured using a 3D laser scanner. Flatfoot evaluations were conducted using the Sztriter-Godunov index (KY) from footprints. All measurements were analyzed by age and sex using the mean values of the left and right sides. Comparisons were performed between flatfoot groups, between body mass index (BMI) groups, and between body height groups. The study revealed a significant decrease in the incidence of bipedal flatfoot with age (p < 0.001), whereas the prevalence of obesity remained consistent (p > 0.05). Bipedal flatfoot was associated with distinct morphological changes, including lower arches, reduced instep height, diminished ankle heights and a greater rearfoot valgus angle (p < 0.05). When comparing the BMI groups, overweight children had larger and thicker feet (p < 0.05), but no differences were found in arch height and ankle height (p > 0.05). When comparing the body height groups, short-statured children had a shorter feet girth, shorter arches, and shorter ankle height (p < 0.05), but no differences were found in the rearfoot valgus angle (p > 0.05).

CONCLUSION

The main characteristics of flat feet include lower arches and instep heights and ankle heights but higher rearfoot valgus angles. In general, overweight children's feet do not have the common features of flat feet. In contrast, short children had similar features of flatfoot except for rearfoot valgus. Assessment of posture, such as rearfoot valgus, can be critical in identifying children with flat feet.

WHAT IS KNOWN

• The morphology of children's feet is associated with body growth, but the relationship between flatfeet and body mass and height remains controversial.

WHAT IS NEW

• Three-dimensional foot measurement shows that body mass is generally not associated with flatfeet, while short children have lower arches but no rearfoot valgus.

A parametric design framework for the mass customization of bicycle helmet

Cluster analysis of 3D head shapes plays a crucial role in the mass customization design of products related to the head. Head shapes exhibit variations across different races, and designing helmets exclusively for Chinese individuals cannot solely rely on or reference foreign head models. Currently, research on cluster analysis of Chinese head shapes is limited, especially concerning shape variances. To address this, we developed an improved k-medoids algorithm and integrated Cluster Validity Index as an assessment metric. This enabled us to cluster 339 Chinese young males aged 18 to 30 into 7 groups based on their head shapes. By comparing our improved algorithm to the traditional k-medoids method, we affirmed its superiority in achieving higher sample participation rates and reducing inter-cluster sample disparities. To simplify the helmet design and editing process, and to improve the efficiency of mass customization, we have developed a parametric modeling program for bicycle helmets based on the head shape clustering results. Results from the Helmet Fit Index and stress simulation analysis demonstrate that our approach significantly enhances helmet fit and wearer comfort.

The Effect of Anthropometric Shoes on Lactic Acid Reduction in Nurses: A Mixed-Methods Study from Indonesia

Background

The mobilization characteristics of nurses' work, such as standing, walking, and transferring patients for a long time, can increase the risk of musculoskeletal disorders. Repetitive activities nurses perform can cause foot problems such as discomfort and insecurity, characterized by increased lactic acid levels. Anthropometric shoes are specifically designed to reduce complaints on nurses' feet.

Purpose

This study aimed to determine the effect of individual anthropometric shoes on lactic acid levels in nurses at the hospital.

Methods

This study used a mixed-method study design. This study involved 71 nurses in the quantitative study and 15 nurses in the qualitative study. Nurses in Emergency Room, Central Surgical Installation, Inpatient Room, Intensive Care Unit, and Outpatient Installation were randomly selected using a stratified random sampling technique. The instruments used were the Accutrend Lactacyd tool, demographic questionnaire and interview questionnaire. Bivariate data analysis was using Statistical Package for Social Sciences (SPSS) and qualitative data analysis using thematic analysis.

Results

This mixed-method study shows that anthropometric shoes can reduce nurses' lactic acid levels. In the quantitative study; there was a significant difference in lactic acid levels of nurses before and after using anthropometric shoes with the average results of measuring lactic acid levels, namely pre-test (22.48 mg/dL) and post-test (16.27 mg/dL), with a p-value (0.000). The qualitative study data revealed positive results related to increased nurse knowledge, positive views on the effect of shoes on nurse performance, and the impact of using anthropometric shoes in providing comfort and safety, such as decreased muscle fatigue and pain.

Conclusion

The findings of this study highlight the effect of individualized anthropometric shoes on lactic acid levels in nurses in Indonesian hospitals. It is essential to conduct further research and evaluate the results in a broader setting to ensure that anthropometric shoes can directly affect lactic acid levels.

What do male netball players want in their footwear? Design recommendations for netball-specific shoes for men

With the increasing professionalisation of men's netball and the high prevalence of foot-related problems and pain, manufacturers must develop shoes with the correct ergonomic design to meet the unique needs of male netball players. This study aimed to determine what factors men consider when selecting a netball-specific shoe and what design features they want in an ideal netball-specific shoe. 279 amateur, sub-elite and elite male netball players completed a 38-question online survey about their footwear habits and preferences. Support was the most influential factor when men selected a netball-specific shoe. A wider toe-box, more durable upper and outsole, and added cushioning and support in the midsole and insole were preferred fit, form and function features for an ideal netball-specific shoe. We recommend that manufacturers develop a range of netball-specific shoes based on the foot dimensions, playing demands and preferences of male netball players to meet men's fit and functionality requirements.

Methodological and statistical approaches for the assessment of foot shape using three-dimensional foot scanning: a scoping review

OBJECTIVE

The objectives of this study were to: (i) review and provide a narrative synthesis of three-dimensional (3D) foot surface scanning methodological and statistical analysis protocols, and (ii) develop a set of recommendations for standardising the reporting of 3D foot scanning approaches.

METHODS

A systematic search of the SCOPUS, ProQuest, and Web of Science databases were conducted to identify papers reporting 3D foot scanning protocols and analysis techniques. To be included, studies were required to be published in English, have more than ten participants, and involve the use of static 3D surface scans of the foot. Papers were excluded if they reported two-dimensional footprints only, 3D scans that did not include the medial arch, dynamic scans, or derived foot data from a full body scan.

RESULTS

The search yielded 78 relevant studies from 17 different countries. The available evidence showed a large variation in scanning protocols. The subcategories displaying the most variation included scanner specifications (model, type, accuracy, resolution, capture duration), scanning conditions (markers, weightbearing, number of scans), foot measurements and definitions used, and statistical analysis approaches. A 16-item checklist was developed to improve the consistency of reporting of future 3D scanning studies.

CONCLUSION

3D foot scanning methodological and statistical analysis protocol consistency and reporting has been lacking in the literature to date. Improved reporting of the included subcategories could assist in data pooling and facilitate collaboration between researchers. As a result, larger sample sizes and diversification of population groups could be obtained to vastly improve the quantification of foot shape and inform the development of orthotic and footwear interventions and products.

Analysis of skeletal characteristics of flat feet using three-dimensional foot scanner and digital footprint

Background

Flat feet increase the risk of knee osteoarthritis and contribute to frailty, which may lead to worse life prognoses. The influence of the foot skeletal structure on flat feet is not yet entirely understood. Footprints are often used to evaluate feet. However, footprint-based measurements do not reflect the underlying structures of feet and are easily confounded by soft tissue. Three-dimensional evaluation of the foot shape can reveal the characteristics of flat feet. Therefore, foot shape evaluations have garnered increasing research interest. This study aimed to determine the correlation between the three-dimensional (3D) features of the foot and the measurement results of footprint and to predict the evaluation results of flat feet from the footprint based on the 3D features. Finally, the three-dimensional characteristics of flat feet, which cannot be revealed by footprint, were determined.

Methods

A total of 403 individuals (40–89 years) participated in this study. The proposed system was developed to identify seven skeletal features that were expected to be associated with flat feet. The loads on the soles of the feet were measured in a static standing position and with a digital footprint device. Specifically, two footprint indices were calculated: the Chippaux–Smirak index (CSI) and the Staheli index (SI). In the analysis, comparisons between male and female measurement variables were performed using the Student’s t test. The relationships between the 3D foot features and footprint index parameters were determined by employing the Pearson correlation coefficient. Multiple linear regression was utilized to identify 3D foot features that were strongly associated with the CSI and SI. Foot features identified as significant in the multivariate regression analysis were compared based on a one-way analysis of variance (ANOVA) with Tukey’s post hoc test.

Results

The CSI and SI were highly correlated with the instep height (IH) and navicular height (NH) of the 3D foot scanning system and were also derived from multiple regression analysis. In addition to the NH and IH, the indicators of the forefoot, transverse arch width, and transverse arch height were considered. In the flat foot group with CSI values above 62.7%, NH was 13.5% (p < 0.001) for males and 14.9% (p = 0.01) for females, and the axis of the bone distance was 5.3% (p = 0.05) for males and 4.9% (p = 0.10) for females. In particular, for CSI values above 62.7% and NH values below 13%, the axis of the bone distance was large and the foot skeleton was deformed.

Conclusions

Decreased navicular bone height could be evaluated with the 3D foot scanning system even when flat feet were not detected from the footprint. The results indicate that the use of quantitative indices for 3D foot measurements is important when evaluating the flattening of the foot.

Trial registration number UMIN000037694.

Name of the registry: University Hospital Medical Information Network Registry.

Date of registration: August 15, 2019.

A study on segmentation and refinement of key human body parts by integrating manual measurements

Optimal ergonomic design for consumer goods (such as garments and furniture) cannot be perfectly realised because of imprecise interactions between products and human models. In this paper, we propose a new body classification method that integrates human skeleton features, expert experience, manual measurement methods, and statistical analysis (principal component analysis and K-means clustering). Taking the upper body of young males as an example, the proposed method enables the classification of upper bodies into a number of levels at three key body segments (the arm root [seven levels], the shoulder [five levels], and the torso [below the shoulder, eight levels]). From several experiments, we found that the proposed method can lead to more accurate results than the classical classification methods based on three-dimensional (3 D) human model and can provide semantic knowledge of human body shapes. This includes interpretations of the classification results at these three body segments and key feature point positions, as determined by skeleton features and expert experience. Quantitative analysis also demonstrates that the reconstruction errors satisfy the requirements of garment design and production. Practitioner summary The acquisition and classification of anthropometric data constitute the basis of ergonomic design. This paper presents a new method for body classification that leads to more accurate results than classical classification methods (which are based on human body models). We also provide semantic knowledge about the shape of human body. The proposed method can also be extended to 3 D body modelling and to the design of other consumer products, such as furniture, seats, and cars. Abbreviations: PCA: principal component analysis; KMO: Kaiser-Meyer-Olkin; ANOVA: analysis of variance; 3D: three-dimensional; 2D: two-dimensional; ISO: International Standardisation Organisation; BFB: body-feature-based.

Stature estimation from various three-dimensional anthropometric foot measurements of Taiwanese female population

Predicting a victim's stature from a dismembered body or human remains is a challenge in forensic practice. Lower extremity dimensions, such as the foot, are essential measurements for stature estimation. However, there is no available information on stature prediction generated from Taiwanese female foot measurements in the forensic science field. Hence, this study aims to investigate the correlations between various foot dimensions and stature and develop population-specific stature-prediction equations for Taiwanese females. Bilateral data of 12 foot dimensions were collected from 1058 females aged from 18 to 59 years using three-dimensional scanning. A pairedt-test is performed to evaluate bilateral differences, and linear and stepwise regression analyses are performed to generate stature predictions. The results indicate significant bilateral differences in the majority of the foot measurements. All measurements are positively correlated with stature (p < .05). Higher correlation coefficients with stature are observed in length-related foot dimensions, followed by girth- and breadth-related dimensions. The foot length on both sides is selected as an accurate and reliable parameter to conduct linear stature-predicting regression for Taiwanese females because it exhibits the highest explanation rate (right: 54.1%; left: 50.8%) and lowest estimating standard error (right: 3.883 cm, left: 4.020 cm) among the 12 foot measurements. Based on the results of the stepwise regression analysis, several stature-prediction equations consisting of various foot measurements are established. The findings of this study can provide helpful information for predicting the stature of Taiwanese females from fragmentary foot remains.

Stature estimation using foot dimensions via 3D scanning in Taiwanese male adults

In forensic identification, the use of foot dimensions to predict stature is a requisite. For Taiwanese male stature prediction, available information about stature estimation using foot dimensions is still lacking. Therefore, the primary purpose of this study was to establish Taiwanese adult male stature prediction models for various foot dimensions. A total of 2,072 male 3D foot models were collected and the subjects' ages ranged from 18 to 59 years old. Thirteen foot dimensions for each foot were utilized in this study. Bilateral differences were tested using pairedt-tests. Stature predictions based on different foot dimensions were conducted using simple linear and stepwise regression methods. The results showed significant bilateral differences in the majority of the selected foot dimensions (p < 0.001). Foot length had the highest positive correlation with stature in the right and left foot. Using length-related dimensions generated better prediction accuracy (0.356 < R² < 0.533, 4.193 < SEE < 4.928), whereas the worst accuracy was observed with angle-related dimensions (0.001 < R² < 0.023; 6.072 < SEE < 6.137) when employing a single foot dimension to estimate Taiwanese male stature. Stepwise regression analysis results indicated that the coefficient of determination was improved to 0.590 and 0.593 by applying five and six foot parameters to predict stature, respectively. The findings of the present study suggest that these stature estimation equations can be applied to predict Taiwanese male stature in the forensic science field.

Differences in foot dimensions between children and adolescents with and without Down syndrome

PURPOSE

This study compared the differences in foot dimensions between children with and without Down syndrome using three-dimensional (3D) foot scans.

METHODS

51 children with and 51 children without Down syndrome had a 3D scan taken of their right foot to compare the absolute and normalised (for height or foot length) measurements.

RESULTS

Normalised foot length was shorter in children with Down syndrome (MD -11.62 mm, 95% CI -15.06 to -8.18, p < 0.001). When normalised for foot length, ball of foot length (MD 2.87 mm, 95% CI 1.17 to 4.58, p = 0.001), diagonal and horizontal foot width (MD 3.65 mm, 95% CI 1.65 to 5.66, p < 0.001; MD 4.80 mm, 95% CI 2.88 to 6.72, p < 0.001, respectively), ball and instep girth (MD 10.60 mm, 95% CI 5.96 to 15.25, p < 0.001; MD 7.92 mm, 95% CI 3.02 to 12.82, p = 0.002, respectively) and fifth toe height (MD 3.14 mm, 95% CI 2.22 to 4.07, p < 0.001) were greater in children with Down syndrome.

CONCLUSIONS

Children with Down syndrome have shorter, wider feet with greater girth and fifthtoe height measurements relative to children without Down syndrome. These findings have implications for footwear fit and the manufacturing of population-specific footwear.IMPLICATIONS FOR REHABILITATIONFootwear-fitting issues arise as a result of the unique foot shape of children with Down syndrome.There are substantial variations in the foot shape of children with and without Down syndrome.Children with Down syndrome require wider, deeper footwear at a given length to accommodate their foot dimensions.These findings have implications for the manufacturing of population-specific footwear.

Statistical ankle-shape and pressure analysis for design of elastic tubular bandage

Ankles can benefit from the elastic tube bandage (ETB) by providing the ankle joint with compression, but partial high- or low-pressure leads to body discomfort. The aim of this paper is to propose a method for analyzing the ankle shape with the fabric compression which is basis on the comfortable pressure on human body. First, a standard model of ankle is established from the scanned data of 306 samples, and the mapping of the fabric shape curves on ankle were constructed by the U-direction convex curves of the model. The positions or areas of maximum and minimum pressure are then marked by extracting the curvatures of the fabric shape curves. According to the Laplace's Law, the sizes of ETBs can be calculated given that the value of comfortable pressure on human body is the maximum one. The data of calculation is approximate to the relevant previous studies which has the same parameters of ETBs. Nine groups of the ankle shapes from the database are discussed, each group has a proportional coefficient to the standard model, and the result shows that six sizes of ETBs with comfort pressure match for the nine groups. These can be applied to the comfort design, and the method proposed can boost size customization of ETBs, as well as will inspire the research on other elastic compression garments.

Reproducibility of foot dimensions measured from 3-dimensional foot scans in children and adolescents with Down syndrome

BACKGROUND

Children and adolescents with Down syndrome have a distinctive foot shape (such as wide and flat feet) that often leads to difficulty with footwear fitting. 3-dimensional (3D) scanning can accurately measure the foot dimensions of individuals with Down syndrome, which may assist shoe fit. However, the reproducibility of measuring foot dimensions using 3D scans in children and adolescents with Down syndrome is unknown. The aim of this study was to determine the intra- and inter-rater reproducibility of measuring foot dimensions of children and adolescents with Down syndrome using 3D scanning.

METHODS

3D foot scans of 30 participants with Down syndrome aged 5 to 17 years were obtained using the FotoScan 3D scanner. Foot dimensions assessed were foot length, ball of foot length, outside ball of foot length, diagonal foot width, horizontal foot width, heel width, ball girth, instep girth, first and fifth toe height, and instep height. Additionally, the Wesjflog Index and forefoot shape were determined. Measurements were completed by two raters independently on two separate occasions, 2 weeks apart. Intra- and inter-rater reliability were assessed using intra-class correlation coefficients (ICCs) and Gwet's AC1 statistics with 95% confidence intervals. Agreement was determined by calculating limits of agreement (LOA) and percentage agreement.

RESULTS

Eighteen participants were female and 12 were male (mean age 10.6 [3.9] years). Intra-rater reproducibility (ICCs ranged from 0.74 to 0.99, 95% LOA from - 13.7 mm to 16.3 mm) and inter-rater reproducibility (ICCs ranging from 0.73 to 0.99, 95% LOA from - 18.8 mm to 12.7 mm) was good to excellent, although some measurements (ball of foot length, outside ball of foot length, heel width and girth measurements) displayed wider LOAs indicating relatively poorer agreement. Forefoot shape displayed substantial to almost perfect reliability (Gwet's AC1 0.68 to 0.85) and percentage agreement ranged from 73 to 87%, indicating acceptable agreement.

CONCLUSIONS

The measurement of specific foot dimensions of children and adolescents with Down syndrome using 3D scans is reproducible. Findings of this study may be used to support future research measuring specific foot dimensions of children and adolescents with Down syndrome using 3D foot scans.

Morphological variations of the human talus investigated using three-dimensional geometric morphometrics

INTRODUCTION

The shape of the talus determines the positional and kinematic features of the subtalar, talonavicular, and talocrural joints during walking. Thus, detailed knowledge of the pattern of sexual dimorphism of the human talus may be useful for revealing the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. The aim of this study was to characterize and visualize the three-dimensional shape variations of the talus in relation to sex and age using geometric morphometrics.

MATERIALS AND METHODS

Computed tomography images of 56 feet without talar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on a bone model of the talus to calculate principal components (PCs) of shape variations among specimens. PC scores were compared between sexes, and their correlations with age were also investigated.

RESULTS

The female talus had a longer neck and narrower head width than the male talus. The superior trochlea was tilted more laterally in the frontal plane in females. Furthermore, the female talar head was more twisted and was more elongated in the dorsoplantar direction.

CONCLUSIONS

Morphological features of the talus in females could alter the subtalar and talonavicular joint kinematics during walking and could be a structural factor in the pathogenetic mechanism underlying foot and knee disorders. This study contributes to the comprehensive understanding of shape variations in the human talus.

Prediction of Optimized Color Design for Sports Shoes Using an Artificial Neural Network and Genetic Algorithm

Product design is a complicated activity that is highly reliant on individual impressions, feelings and emotions. Back-propagated neural networks have already been applied in Kansei engineering to solve difficult design problems. However, artificial neural networks (ANNs) have a slow rate of convergence, and find it difficult to devise a suitable network structure and find the global optimal solution. This study developed an ANN-based predictive model enhanced with a genetic algorithm (GA) optimization technique to search for close-to-optimal sports shoe color schemes for a given product image. The design factors of the sports shoe were set as the network inputs, and the Kansei objective value was the output of the GA-based ANN model. The results show that a model built with three hidden layers (28 × 38 × 19) could predict the object value reliably. The R2 of the preference objective was equal to 0.834, suggesting that the developed model is a feasible and efficient tool for predicting the objective value of product images. This study also found that the prediction accuracy for shoes with two colors was higher than that for shoes with only one color. In addition, the prediction accuracy for shoes with a relatively familiar shape was also higher. However, the prediction of color preferences is relatively difficult, because the respondents had different individual color preferences. Exploring the sensitivity and importance of the visual factors (form, color, texture) for various image words is a worthy topic for future research in this field.

A data-driven classification of 3D foot types by archetypal shapes based on landmarks

The taxonomy of foot shapes or other parts of the body is important, especially for design purposes. We propose a methodology based on archetypoid analysis (ADA) that overcomes the weaknesses of previous methodologies used to establish typologies. ADA is an objective, data-driven methodology that seeks extreme patterns, the archetypal profiles in the data. ADA also explains the data as percentages of the archetypal patterns, which makes this technique understandable and accessible even for non-experts. Clustering techniques are usually considered for establishing taxonomies, but we will show that finding the purest or most extreme patterns is more appropriate than using the central points returned by clustering techniques. We apply the methodology to an anthropometric database of 775 3D right foot scans representing the Spanish adult female and male population for footwear design. Each foot is described by a 5626 × 3 configuration matrix of landmarks. No multivariate features are used for establishing the taxonomy, but all the information gathered from the 3D scanning is employed. We use ADA for shapes described by landmarks. Women’s and men’s feet are analyzed separately. We have analyzed 3 archetypal feet for both men and women. These archetypal feet could not have been recovered using multivariate techniques.

Analysis of 1.2 million foot scans from North America, Europe and Asia

For decades, footwear brands have developed products using outdated methods and measurements, working with limited insight into the foot shapes and dimensions of their target customers. The integration of 3D scanning technology into footwear retail stores has made it possible for this research to analyze a database containing a large number of male and female 3D foot scans collected across North America, Europe, and Asia. Foot scans were classified into length classes with 5mm length increments; mean width, instep height, and heel width were calculated for each length class. This study confirms the existence of many statistically significant differences in mean foot measurements amongst the regions and between the sexes, and a large dispersion of foot measurements within each group of customers. Therefore, shoes should be developed separately for each group, region, and sex, and at least 3 shoe widths per length class are required to provide a proper fit for 90% of customers. Beyond this, our analysis asserts that a shoe designed for a single group will fit a different segment of the population in another group, and that existing last grading tables should be updated to reflect the foot dimensions of current consumers.

Flatfeet: Biomechanical implications, assessment and management

Several complications due to flatfeet have been reported in previous literature such as poor postural stability, injuries, pathologies, and discomfort. Early detection and appropriate management are mandatory to minimize these effects. There are different feet assessments established in the field with distinct advantages and disadvantages. Additionally, selection of management methods from various options should be done vigilantly as the application differs according to the individual. Therefore, the objective of this article is to review previous literature on structural anatomy, pathomechanics, assessment, and proper management of flatfeet to provide a condensed summary for healthcare professionals, occupational therapists, kinesiologists, biomechanists, coaches, and ergonomists.

A review of the methodology and applications of anthropometry in ergonomics and product design

Anthropometry is a key element of ergonomic studies for addressing the problem of fitting the tasks/products to user characteristics, but there is a gap between anthropometric data and their application for designing ergonomic products and environments. This research was conducted to review the literature on the methodology and applications of anthropometry for the ergonomic design of products and environments, and to identify where further research is needed to improve its application and evaluation protocols. One hundred and sixteen papers meeting the inclusion criteria were reviewed. Although a number of anthropometric investigations have been conducted to improve the design of products/environments for different users, further research seems to be necessary, particularly for special groups, such as children, the elderly and people with disabilities. Different anthropometric measurement methods/techniques and fitting criteria are discussed regarding their applicability for various design applications. This review also highlights methodological issues (sampling considerations and prototype evaluation and testing) that should be considered in future research to ensure a user-centred approach of the design process. Practitioner Summary: A literature review was conducted on the methodology and applications of anthropometry for the ergonomic design of products/environments. This review emphasises the need for anthropometric research to design for special groups, such as children, the elderly and people with disabilities, and methodological issues that should be considered in future research. Abbreviations: 1D: one-dimensional; 2D: two-dimensional; 3D: three-dimensional; HF/E: Human Factors/Ergonomics; PCA: Principal Components Analysis; CA: Cluster Analysis; DHM: Digital Human Modelling.

Development of a Footwear Sizing System in the National Football League

Context:

Footwear performance and injury mitigation may be compromised if the footwear is not properly sized for an athlete. Additionally, poor fit may result in discomfort and foot injury such as fifth metatarsal stress fracture, foot deformities, turf toe, and blisters. Current footwear fitting methods consist of foot length and width measurements, which may not properly describe the shape of the individual foot, correlated with shoe size descriptors that are not standardized. Footwear manufacturers employ a range of sizing rubrics, which introduces shoe size and shape variability between and even within footwear companies. This article describes the synthesis of literature to inform the development and deployment of an objective footwear fitting system in the National Football League (NFL). The process may inform athletic footwear fitting at other levels of play and in other sports.

Evidence Acquisition:

Literature related to footwear fitting, sizing, and foot scanning from 1980 through 2017 was compiled using electronic databases. Reference lists of articles were examined for additional relevant studies. Sixty-five sources are included in this descriptive review.

Study Type:

Descriptive review.

Level of Evidence:

Level 5.

Results:

Current methods of footwear fitting and variability in the size and shape of athletic footwear complicate proper fitting of footwear to athletes. An objective measurement and recommendation system that can match the 3-dimensional shape of an athlete’s foot to the internal shape of available shoe models can provide important guidance for footwear selection. One such system has been deployed in the NFL.

Conclusion:

An objective footwear fitting system based on 3-dimensional shape matching of feet and shoes can facilitate the selection of footwear that properly fits an athlete’s foot.

Study on the foot shape characteristics of the elderly in China

BACKGROUND

With aging, the feet of the elderly above 60 years old in China present degenerative changes, deformities, and diseases, which significantly affect their daily activities.

OBJECTIVES

The authors aimed to study the morphological characteristics of the feet and identify the foot type according to size (length and width) and defect characteristics of elderly feet in China.

METHODS

A convenient sample of 1000 subjects above 60 years old was recruited mainly in the regions of Shanghai, Shaanxi, Henan, Hebei, and Sichuan in China. Foot images were collected, and 800 (male 398, female 402) valid questionnaires were recovered. A total of 800 elderly subjects as the test group were invited to measure their foot sizes by means of a Footprint Collector (Tong Yuan Tang Health Management Limited, Qingdao in Shandong province). The foot type of the elderly was compared with that of the general adult Chinese population as the control group using the t-test for independent samples.

RESULTS

Hallux valgus (46.9%) and flat foot (50.0%) were the most common foot shape deformities. The most frequent foot diseases were foot scaling (91.2%) and calluses (96.3%). The medial width of the first metatarsal-toe joint of the elderly was significantly higher (elderly female, 44.95±4.86mm; elderly male, 48.55±4.94mm) than that of the general adult population (adult female, 40.18±3.43mm; adult male, 43.22±3.20mm) (p<0.01).

CONCLUSION

The foot length of the elderly was not significantly different from that of the general adult Chinese population. The width of the first metatarsal-toe joint in the forefoot of the elderly was significantly higher than that of the general adult Chinese population, which was consistent with the result that a high proportion of elderly subjects presented hallux valgus.

Using subject-specific three-dimensional (3D) anthropometry data in digital human modelling: case study in hand motion simulation

Digital human modelling enables ergonomists and designers to consider ergonomic concerns and design alternatives in a timely and cost-efficient manner in the early stages of design. However, the reliability of the simulation could be limited due to the percentile-based approach used in constructing the digital human model. To enhance the accuracy of the size and shape of the models, we proposed a framework to generate digital human models using three-dimensional (3D) anthropometric data. The 3D scan data from specific subjects' hands were segmented based on the estimated centres of rotation. The segments were then driven in forward kinematics to perform several functional postures. The constructed hand models were then verified, thereby validating the feasibility of the framework. The proposed framework helps generate accurate subject-specific digital human models, which can be utilised to guide product design and workspace arrangement. Practitioner Summary: Subject-specific digital human models can be constructed under the proposed framework based on three-dimensional (3D) anthropometry. This approach enables more reliable digital human simulation to guide product design and workspace arrangement.