Feet Wide Research Articles

Worn region size of shoe outsole impacts human slips: Testing a mechanistic model

Shoe outsole tread wear has been shown to increase slip risk by reducing the tread’s ability to channel fluid away from the shoe-floor interface. This study establishes a connection between geometric features of the worn region size and slipping. A mechanistic pathway that describes the relationship between the worn region size and slip risk is assessed. Specifically, it is hypothesized that an increased worn region size leads to an increase in under-shoe fluid pressure, which reduces friction, and subsequently increases slipping. The worn region size, fluid pressure, and slip outcome were recorded for 57 participants, who were exposed to an unexpected slip condition. Shoes were collected from each participant and the available coefficient of friction (ACOF) was measured using a tribometer. A greater shoe worn region size was associated with increased slip occurrence. Specifically, a 1 mm increase in the characteristic length of the worn region (geometric mean of its width and length) was associated with an increase in slip risk of ~10%. Fluid pressure and ACOF results supported the mechanistic model: an increase in worn region size correlated with an increase in peak fluid pressure; peak fluid pressures negatively correlated with ACOF; and increased ACOF correlated with decreased slip risk. This finding supports the use of worn region size as a metric to assess the risk of slipping.

Shape optimization of running shoes with desired deformation properties

The present paper describes a shape optimization procedure for designing running shoes, focusing on two mechanical properties, namely, the shock absorption and the stability keeping the right posture. These properties are evaluated from two deformations of a sole at characteristic timings during running motion. We define approximate planes for the deformations of sole’s upper boundary by least squares method. Using the planes, we choose the tilt angle in the shoe width direction at the mid stance phase of running motion as an objective function representing the stability, and the sunk amount at the contact phase of running motion as a constraint function representing the shock absorption. We assume that the sole is a bonded structure of soft and hard hyper-elastic materials, and the bonding and side boundaries are variable. In this study, we apply the formulation of nonparametric shape optimization to the sole considering finite deformation and contact condition of the bottom of the sole with the ground. Shape derivatives of the cost (objective and constraint) functions are obtained using the adjoint method. The H1 gradient method using these shape derivatives is applied as an iterative algorithm. To solve this optimization problem, we developed a computer program combined with some commercial softwares. The validity of the optimization method is confirmed by numerical examples.

Anatomical calcaneal external fixator self-designed according to the morphology of heel

The anatomical calcaneal external fixator was designed by measuring and calculating the morphological data of the heel. A total of 100 normal people were randomly selected to obtain 200 hind foot data, including 45 males and 55 females, with an average age of 43.9 years (range, 19-67 years). According to the principles of human engineering and local anatomy, the morphological data of the heel in the weight-bearing standing position and supine position were measured with the direct measurement mode. The heel length, heel width, heel height, medial ankle height, lateral ankle height, and calcaneal pitch angle (CPA) were measured by vernier calipers and ulnar markers in weight-bearing standing position, and the gender groups and left and right foot groups were compared; the shape of the hind foot in the supine position was measured by three-dimensional (3D) dot matrix inverse model method. According to the stereoscopic data of the comprehensive anatomical morphology of the heel, the anatomical calcaneal external fixator was designed with AutoCAD 2019 and other 3D industrial design softwares. The measurements of shoe size, heel length, heel width, heel height, medial ankle height, lateral ankle height, and CPA in male were significantly higher than those in female ( P<0.05). There was no significant difference between the left and right feet in the other indexes except that the height of the medial malleolus of the left foot was significantly lower than that of the right foot ( t=-2.827, P=0.005). The measurement of 3D dot matrix inverse model in supine position showed that the heel part was non-circular arc edge, and many groups of arc edges fluctuate in a limited range. Based on the above data, an anatomical calcaneal external fixator was designed, which could fit the anatomic radian in theory, so as to be flexible in configuration. On this basis, the ordinary configuration, compression configuration, and orthodontic configuration were designed to meet the treatment needs of calcaneal fractures in different degrees. The ordinary configuration was suitable for patients with Sanders Ⅰ, ⅡA, and ⅡB calcaneal fractures with no or slight displacement of intra-articular fractures; the ordinary configuration was mainly used for simple fixing. The compression configuration was suitable for patients with Sanders ⅡC, ⅢA, and ⅢB, tongue fractures, and avulsion fractures with severe displacement of intra-articular fractures; the compression configuration used obliquely drawn console wires to fix the displaced bones. The orthodontic configuration was suitable for patients with Sanders ⅢC and Ⅳ calcaneal fractures with severe displacement of intra-articular fractures or severe calcaneal bone defects; the orthodontic configuration was a multi-module design, which took into account the stable fixation of the fracture and the arbitrary adjustment of the joint fixation angle. The hind foot is special for morphology, so the external fixator designed based on the vernier caliper measurement method and 3D dot matrix measuring plate measurement method is an anatomical type and its configuration can theoretically meet stable and flexible clinical needs.

A Customized Convolutional Neural Network Model Integrated With Acceleration-Based Smart Insole Toward Personalized Foot Gesture Recognition

Foot gestures play an important role in human machine interface and also indicate the lower-limb motor functionalities. Lately, machine learning models have been integrated with different kinds of wearable devices for foot gesture recognition. However, most existing wearable devices lack of robustness and facileness and existing machine learning models suffer from inconsistent recognition accuracy due to limited and unbalanced training datasets and, therefore, do not work well for new users. To address this, a customized convolutional neural network model architecture is designed, and strategies for achieving personalized models are presented, considering potential fairness sensitive attributes of a diverse training group, including age, gender, body mass index (defined by height and weight), shoe size, and health conditions. The proposed model to be embodied into a flexible smart insole with only two accelerometers aims to recognize four types of foot gestures-toe tapping, heel tapping, foot kicking, and foot stepping-in a sitting posture at high accuracies. After the hyperparameters are well-tuned, average recognition accuracy reaches 92% in training sets, 88.05% in validation sets, 85.27% in test sets, and 83.09% in fivefold cross-validation. The evaluation results from both in-group and leave-one-subject-out show that our unified model is easily transformable for individual uses by further fine-tuning the key hyperparameters.

Characteristics of Shoes with Musculoskeletal Complaints on Foot and Ankle of Sales Promotion Girl

Musculoskeletal complaints are a series of aches in the tendons, muscles, and nerves due to activities with high repetition rates resulting in tissue damage and pain in the muscles. Musculoskeletal complaints are experienced by many female workers due to work demands. Job demands such as the obligation to use high heels when working. Jobs related to the use of high heels are sales promotion girl (SPG). This study uses a quantitative approach. This type of research is observational analytic with cross sectional design. The assessment of musculoskeletal complaints in this study used the Foot and Ankle Outcomes Score (FAOS) questionnaire. Based on the results of the Spearman test factors associated with musculoskeletal complaints on feet and ankles of SPG at Golden Market Jember include individual factors consisting of length of work (ρ = 0,000; r = 0.617; negative direction), BMI (ρ = 0.022; r = 0.314; unidirectional), and sports habits (ρ = 0.045; r = 0.617, opposite). The work factor is static position (ρ = 0,000; r = 0.530; opposite). Shoe characteristic variables consist of shoes type (ρ = 0.022; r = 0.313, opposite), duration of use (ρ = 0,000; r = 0.547; direction), high heels (ρ = 0,000; r = 0.855; direction), and suitability shoe size (ρ = 0,000; r = 0.584; unidirectional). Factors not related to musculoskeletal complaints on the feet and ankles are age (ρ = 0.027; r = 0.850; unidirectional).

Subject-specific identification of three dimensional foot shape deviations using statistical shape analysis

The high prevalence of foot pain, and its relation to foot shape, indicates the need for an expert system to identify foot shape abnormalities. Yet, to date, no such expert system exists that examines the full 3D foot shape and produces an intuitive explanation of why a foot is abnormal. In this work, we present the first such expert system that satisfies those goals. The system is based on the concept of model-based outlier detection: a statistical shape model (SSM) is generated from 186 3D optical foot scans of healthy feet. This model acts as a knowledge base which is then parameterized by one’s demographic characteristics (e.g., age, weight, height, shoe size) through a multivariate regression. This regression introduces model flexibility as it allows the model to be fine tuned to a specific individual. This fine tuned model is then used as a baseline to which the individual’s 3D foot scan can be compared using standard statistical tests (e.g. t-tests). These statistical tests are performed at each vertex along the foot surface to identify the degree and location of shape outliers. Our expert system was validated on foot scans from patients with hallux valgus and abnormal foot arches. As expected, our results varied per patient, confirming that feet with the same clinical classification still show high shape variability. Additionally, the foot shape abnormalities identified by our system not only agreed with the expected location and severity of the tested foot deformities, but our analysis of the full 3D foot shape was able to completely characterize the extent of those abnormalities for the first time. These results show that the combination of statistical shape modelling, multivariate regression, and statistical testing is powerful enough to perform outlier detection for 3D foot shapes. The resulting insights provided by this system could prove useful in both shoe design and clinical diagnosis.

Load-bearing characteristics of square footing on geogrid-reinforced sand subjected to repeated loading

A series of dynamic model tests that were performed on a geogrid-reinforced square footing are presented. The dynamic (sinusoidal) loading was applied using a mechanical testing and simulation (MTS) electro-hydraulic servo loading system. In all the tests, the amplitude of loading was ±160 kPa; the frequency of loading was 2 Hz. To better ascertain the effect of reinforcement, an unreinforced square footing was first tested. This was followed by a series of tests, each with a single layer of reinforcement. The reinforcement was placed at depths of 0.3B, 0.6B and 0.9B, where B is the width of footing. The optimal depth of reinforcement was found to be 0.6B. The effect of adopting this value versus the other two depths was quantified. The single layer of geogrid had an effective reinforcement depth of 1.7B below the footing base. The increase of the depth between the topmost geogrid layer and the bottom of the footing (within the range of 0.9B) did not change the failure mode of the foundation.

Finite element limit analysis of the seismic bearing capacity of strip footing adjacent to excavation in c-φ soil

ABSTRACT In this study, several effective parameters and geometrical features were considered to present the design charts and the reduction coefficients tables to obtain the bearing capacity of a strip footing placed near a c-ϕ excavation under static and seismic conditions by using Finite Element Limit Analysis (FELA). The effects of setback distance to footing width ratio (L/B), cohesion (c), soil friction angle (ϕ), pseudo-static horizontal earthquake coefficient (kh ), and the height of the excavation to the footing width ratio (H/B) on the bearing capacity and failure mechanism were studied. Also, a design procedure and example of its application were presented to obtain the static and seismic bearing capacities of the strip footing placed near the c-ϕ excavation based on the design charts and the reduction coefficients tables.

Does the shoe really fit? Characterising ill-fitting footwear among community-dwelling older adults attending geriatric services: an observational cross-sectional study

BackgroundFalls in older people are common and can result in loss of confidence, fear of falling, restriction in activity and loss of independence. Causes of falls are multi-factorial. There is a paucity of research assessing the footwear characteristics among older people who are at high risk of falls, internationally and in the Irish setting. The aim of this study was to examine the proportion of older adults attending a geriatric day hospital in Ireland who were wearing incorrectly sized shoes.MethodsA consecutive sample of 111 older adults aged 60 years and over attending a geriatric day hospital in a large Irish teaching hospital was recruited. Demographic data including age, mobility, medications, co-habitation status, footwear worn at home and falls history were recorded. Shoe size and foot length were measured in millimetres using an internal shoe gauge and SATRA shoe size stick, respectively. Participants’ self-reported shoe size was recorded. Footwear was assessed using the Footwear Assessment Form (FAF). A Timed Up and Go (TUG) score was recorded. Functional independence was assessed using the Nottingham Extended Activities of Daily Living (NEADL) Scale. The primary outcome of interest in this study was selected as having footwear within the suggested range (10 to 15 mm) on at least one foot. Participants who met this definition were compared to those with ill-fitting footwear on both feet using Chi-square tests, T-tests or Mann–Whitney U tests.ResultsThe mean difference between shoe length and foot length was 18.6 mm (SD: 9.6 mm). Overall, 72% of participants were wearing footwear that did not fit correctly on both feet, 90% had shoes with smooth, partly worn or fully worn sole treading and 67% reported wearing slippers at home. Participant age, TUG score and NEADL score were not associated with ill-fitting footwear.ConclusionsWearing incorrectly fitting shoes and shoes with unsafe features was common among older adults attending geriatric day services in this study. A large number of participants reported wearing slippers at home.

Scale effect study on the modulus of subgrade reaction of geogrid-reinforced soil

Both experimental and numerical investigations conducted on strip footing laying down over the geogrid reinforced fine sand bed. Firstly, an evaluation of the significance of geogrid reinforcement to enhance the soil’s strength is required to carry out a series of a small-scale model of reinforced and unreinforced soil beneath static loading. Next, the series of the large-scale numerical analyses were implemented to define the soil bed reaction modulus and bearing capacity ratio of reinforced sand soil in plane strain conditions. The Mohr–Coulomb soil constitutive model was used to represent the fine sandy soil and the linear elastic tension model was utilized for modeled geogrid reinforcement elements. One of the most beneficial outcomes in the unreinforced soil case, the ultimate bearing capacity progress occurs by developing the width of the strip footing. Then in reinforcing case, an uppermost geogrid layer’s depth under the footing and the fittest spacing between the reinforcing layers are not affected by the wide ranges of the footing widths. Their optimum values are similar to the works of literature (u/B = 0.3 and h/B = 0.4), but they are affected by soil friction angles. Finally, the achievement of this study indicates that the coefficient of soil reaction is associated with a nonlinear behavior with the relative ratio of tensile stiffness of the geogrid to the elasticity modulus of soil and enhanced by increased the number of geogrid layers. The influence of geogrid length on subgrade modulus is negligible and only the effective depth is affected it. The value of reaction modulus decreases when both the footing width and settlement increase. A simple new method is proposed to determine an approximate value of subgrade reaction modulus in reinforced soils.

Bearing capacity of a strip footing placed next to an existing footing on frictional soil

The ultimate bearing capacity of a single/isolated footing has been investigated intensively by many researchers. Although a lot of studies considered different aspects affecting the bearing capacity, only very few focused on the influence of an existing footing on the bearing capacity of a new footing in its close proximity. In this study, the influence of an existing footing on the ultimate bearing capacity of a recently constructed footing in a close spacing has been investigated with respect to different sizes of the footings, spacings between the footings, friction angles of the subsoil and loads applied on the existing footing. Numerical simulations based on finite-element limit analysis (FELA) are utilized to determine lower and upper bounds of the ultimate bearing capacity which bracket the exact solution from below and above. The results for isolated footings are compared with selected data from literature in terms of the bearing capacity factor Nγ indicating good agreement of both, lower and upper bound values. Accuracy of the results was enhanced by applying an adaptive mesh refinement technique which enabled a more precise approximation of the failure mechanism and a better estimation of the exact solution due to smaller differences between the lower and upper bound solutions. The results for footings placed next to an existing footing are discussed with regard to the interference factor ξγ as well as the shape and size (extend) of the failure mechanism. The results illustrate that two types of failure mechanisms may develop which either extend up to the front edge of the existing footing or pass underneath. Comparisons with previous studies revealed that interference factors have been improved significantly due to utilization of adaptive mesh refinement technique. Moreover, design charts for an estimation of ξγ are presented for variable footing width ratios, spacings between the footings, friction angles of the subsoil and loading factors of the existing footing.

Shallow Foundation Settlement Quantification: Application of Hybridized Adaptive Neuro‐Fuzzy Inference System Model

Settlement simulating in cohesion materials is a crucial issue due to complexity of cohesion soil texture. This research emphasis on the implementation of newly developed machine learning models called hybridized Adaptive Neuro‐Fuzzy Inference System (ANFIS) with Particle Swarm Optimization (PSO) algorithm, Ant Colony optimizer (ACO), Differential Evolution (DE), and Genetic Algorithm (GA) as efficient approaches to predict settlement of shallow foundation over cohesion soil properties. The width of footing (B), pressure of footing (qa), geometry of footing (L/B), count of SPT blow (N), and ratio of footing embedment (Df/B) are considered as predictive variables. Nonhomogeneity and inconsistency of employed dataset is a major concern during prediction modeling. Hence, two different modeling scenarios (i) preprocessed dataset (PP) and (ii) nonprocessed (initial) dataset (NP) were inspected. To assess the accuracy of the applied hybrid models and standalone one, multiple statistical metrics were computed and analyzed over the training and testing phases. Results indicated ANFIS‐PSO model exhibited an accurate and reliable prediction data intelligent and had the highest predictability performance against all employed models. In addition, results demonstrated that data preprocessing is highly essential to be performed prior to building the predictive models. Overall, ANFIS‐PSO model showed a robust machine learning for settlement prediction.

Archeological Resource Survey of a 2.9-mile Proposed Pipeline Corridor on University Lands in Ward County, Texas

At the request of Salt Creek Midstream (SCM), Flatrock Engineering and Environmental, LLC (Flatrock) conducted an intensive archeological resource survey of approximately 2.9 miles (15,312 feet) of a proposed pipeline corridor on University Lands in northern Ward County, Texas. Because the project will take place on property owned by the University of Texas, a political subdivision of the State of Texas, it is subject to the Antiquities Code of Texas (Texas Natural Resources Code, Title 9, Chapter 191) and its associated regulations (13 TAC 26). The archeological survey was carried out under Antiquities Permit Number 9355. A pedestrian field survey was conducted by Flatrock archeologist Joel Butler on March 30 and 31, 2020. A corridor 100 feet in width, encompassing 38.7 acres, was surveyed during fieldwork. Surface visibility ranged from 80 to 100-percent along the 100-foot survey corridor and revealed predominantly heavily disturbed or deflated surfaces. The entire corridor was 100-percent surface inspected and 31 shovel tests were excavated to locate and/or evaluate the potential for buried cultural deposits; all shovel tests were negative. No artifacts or archeological sites were identified during fieldwork and no historic structures were visible from the right-of-way. Flatrock recommends that construction of the pipeline be allowed to proceed as planned, with no further archeological investigations. However, it is recommended that if any cultural resources are encountered during construction, the Texas Historical Commission and University Lands should be notified, and a qualified archeologist should evaluate the findings. No artifacts were collected or curated during this project; field records will be curated at the Center for Archaeological Studies (CAS) at Texas State University, San Marcos.

Perceived changes in the university students’ health behavior after participating in the study on wearing high-heeled shoes

Introduction: Wearing high-heeled shoes (HH) is a wide-spread practice among Western women, maintaining popularity despite its harmful potential. We examined the main motivation behind wearing HH in female students, as well as the possible change to wearing HH among the research participants. Methods: Thirty university students (N=30 females, age 21.8±2.09 years; weight: 55.7±4.05 kg, height: 1.66±0.03 m, BMI: 20.34±1.41 kg.m-2, shoe size: EU 36–38), who rarely wore HH. The participants wore HH for no longer than 6 hours per month during the period two past years. The SonoSens Monitor Analyzer system (Gefremed, Chemnitz, Germany) was used to observe participants’ posture when walking and movements in individual sections of their spines. In a comparative experiment, the correlation between variables recorded when walking in two types of shoes was identified. The first pair of shoes (HH) had 7 cm heels whereas the second were flat sport shoes (FS). Results: The evaluation of participants’ spines and posture when walking in HH and FS revealed significant differences (p &lt; 0.05). The evaluation of the initial and follow-up surveys indicates that the main motivation for wearing HH among the test group was to increase their attractiveness and respond to social expectations. After participating in the research and becoming aware of its outcomes and issues, the test group’s attitude to wearing HH has changed. Conclusions: In regards to good posture and spinal health, this study has raised some awareness amongst its participants, and has therefore proved to be a significant positive influence.

Effect of interference on ultimate bearing capacity of strip footings resting over multi-layered-reinforced soil

ABSTRACT In an attempt to modify the conventional approach of considering homogeneous soil underneath the foundation, a numerical investigation is carried out to evaluate the bearing capacity of two closely spaced identical strip footing on a two-layered soil system. Two different cases including strong soil overlying the weak soil and vice versa have been considered in the analysis. The analysis was carried out for various ratios of clear spacing to the footing width (s/B). The values of critical spacing (s cr ) and significant depths (H s ), beyond which the increase in ultimate bearing capacity ceases were observed. [s cr, Hs ] values were found to be [B, 3B] and [3B, 2B] for strong soil overlying weak soil and weak soil overlying strong soil mass respectively. With the inclusion of geogrid reinforcement, the s cr is obtained as 0.5B and 1.5B in strong soil overlying weak soil and weak soil overlying strong soil respectively.

Behaviour of a Strip Footing Embedded in a Sand Slope Reinforced with Multilayer Geotextile

This paper presents the results of laboratory model tests and numerical analysis on the behaviour of a strip footing embedded in a multilayer geotextile-reinforced sand slope. The investigation was aimed at determining the effect of footing embedment depth $$ D $$ and number of geotextile layers $$ N $$ on the bearing capacity and settlement characteristics of an embedded footing. The results show that the load–settlement behaviour of the embedded footing is significantly affected by $$ D $$ and $$ N $$ . The advantage of reinforcing the slope with more than one geotextile layer and placing the footing below the slope crest has been evaluated using a non-dimensional parameter, called the ultimate bearing capacity ratio $$ {\text{BCR}}_{u} $$ , defined as the ratio of ultimate bearing capacity of the reinforced case to that of unreinforced case. It is observed that $$ {\text{BCR}}_{u} $$ improves with an increase in $$ N $$ but reduces with an increase in $$ D/B $$ , where $$ B $$ is the footing width. The minimum $$ {\text{BCR}}_{u} $$ , $$ {\text{BCR}}_{u} (\hbox{min} ) \approx 2 $$ is observed for $$ N = 1 $$ and $$ D/B = 1 $$ , while the maximum $$ {\text{BCR}}_{u} $$ , $$ {\text{BCR}}_{u} (\hbox{max} ) \approx 6 $$ is attained when the footing is placed at $$ D/B = 0 $$ and $$ N = 3 $$ . A comparison between the numerical and laboratory test results shows a very good agreement.

BEARING CAPACITY OF STRIP FOOTING ON LIME STABILIZED EXPANSIVE CLAYEY SOIL

To investigate and understand the effect of lime on the engineering properties of an expansive clayey soil, 4% lime by weight of the dry soil have been added. The stabilized soil specimens were subjected to unconfined compression, swelling potential and pH value tests. Also, a finite element analyses using PLAXIS-2D software were conducted. The studied parameters include the footing size and thickness of lime stabilized soil, and then compared with the natural soil. It was proved that lime content and curing duration had a significant effect on the engineering properties of lime-treated soil. The curing duration had significantly enhanced the strength properties of the lime stabilized soil specimens, where, unconfined compressive strength has significantly improved. Also, the pH value was decreased with increasing curing durations. Moreover, it was found that the swelling potential of the lime-treated soil specimens was reduced by lime addition and increasing of the curing duration. The results of numerical analysis show that the stress-settlement behaviour and ultimate bearing capacity of footing can be considerably enhanced as the thickness of lime-treated increases, and the influence of footing width seems to be insignificant.

Seven Tips to Effective Running Shoe Sizing.

Seven Tips to Effective Running Shoe Sizing.

Variation in the size of foot and great toe in unilateral CTEV (club foot deformity)

Variation in the size of foot and great toe in unilateral CTEV (club foot deformity) - IJCAP- Print ISSN No: - 2394-2118 Online ISSN No:- 2394-2126 Article DOI No:- 10.18231/j.ijcap.2019.066, Indian Journal of Clinical Anatomy and Physiology-Indian J Clin Anat Physiol

Developing elderly men\u2019s footwear sizing system based on their foot shapes

The purpose of this study was to develop a shoe sizing system for elderly men in Korea based on previous studies which analyzed aspects and shapes of the sole of those who aged 60 years or more. The sizing system creation process included natural log-transformation, principle component analysis, multivariate linear regression, size range determination, and measurements calculation. Measurement interval was set up based on Korea standard (KS). Cross analysis was conducted for basic items to select an interval which indicated frequency of more than 5% by type. A measurement system was then established by type. As results of this study, a shoe sizing system was developed with an interval of 5 mm for foot length, an interval of 3 mm for the circumference of the top of the foot, and an interval of 6 mm for the circumference of the top of the foot within the same foot length standard. To reflect characteristics by type, respective shoe sizing systems in accordance with type were developed. 12 types of shoe sizing systems were suggested for elderly men. Our results indicate that shoe sizing system for elderly men by foot type could improve the suitability of shoes. They could give wider range of shoe sizes and high satisfaction. They can help shoe makers produce shoes with various purposes and functions for seniors.