Shoe Properties Research Articles

Contribution of the prominent Russian hygienist F. G. Krotkov to the development and practical use of military uniforms

The article presents some historical information about the origin and development of the doctrine of clothing in general and military clothing in particular. The data on the conduct of research on the hygienic properties of clothing and shoes by domestic military hygienists are presented. The role of F. G. Krotkov in the development of scientifically based requirements for military uniforms, the relevance of which remains to the present time, is emphasized.

Modeling Running via Optimal Control for Shoe Design.

Shoe manufacturing technology is advancing faster than new shoe designs can viably be evaluated in human subject trials. To aid in the design process, this paper presents a model for estimating how new shoe properties will affect runner performance. This model assumes runners choose their gaits to optimize an intrinsic, unknown objective function. To learn this objective function, a simple two-dimensional mechanical model of runners was used to predict their gaits under different objectives, and the resulting gaits were compared to data from real running trials. The most realistic model gaits, i.e., the ones that best matched the data, were obtained when the model runners minimized the impulse they experience from the ground as well as the mechanical work done by their leg muscles. Using this objective function, the gait and thus performance of running under different shoe conditions can be predicted. The simple model is sufficiently sensitive to predict the difference in performance of shoes with disruptive designs but cannot distinguish between existing shoes whose properties are fairly similar. This model therefore is a viable tool for coarse-grain exploration of the design space and identifying promising behaviors of truly novel shoe materials and designs.

МОДЕЛИРОВАНИЕ ПРОЦЕССА РАССЛАИВАНИЯ КЛЕЕВОГО СОЕДИНЕНИЯ ДЕТАЛЕЙ ВЕРХА ОБУВИ ИЗ ВОЙЛОКА

Increasing interest in environmental protection leads to a search new technologies and attempts to revive old technologies for obtaining and processing materials. Environmentally friendly technologies have become more than popular. Currently produced shoes with uppers made of felt and felt satisfy the consumer in design, internal shape, appearance, and some other indicators, however, the issue of increasing the heat-shielding properties of the seams connecting the upper parts is still relevant. One of the disadvantages of the thread method of assembling a shoe upper blank from felt is heat loss through the seams, insufficient strength, and water permeability. Thread-free methods for connecting parts of shoe uppers can eliminate these disadvantages. The object of study was the technological process of gluing parts of shoe uppers made of felt. The subjects of the study are finished shoes and external parts of felt shoe uppers. The advantages of adhesive assembly of felt shoe upper blanks are considered. It is hypothesized that the adhesive assembly method will preserve the heat-protective and strength properties of felt shoes. To assess the bonding strength of parts, felt samples were glued together with a polychloroprene adhesive solution and examined for delamination. To evaluate the modeling of the delamination process, the theory of crack formation and the adhesive separation model were applied. The finite element method was used to simulate the dynamics of separation of one surface from another. The conducted studies and calculations have proven that when felt samples delaminate, the stress is concentrated in the vicinity of the tear-off point, and then gradually decreases in sections of the tear-off length, where the adhesive resistance force ceases to act. The results of modeling the delamination process were used to predict the behavior of adhesives during the operation of felt shoes under different conditions.

Using Synthetic Data for Wheelchair Footrests Design Customization: The Kyklos 4.0 Approach

Wheelchairs are complex systems often requiring a wide range of adjustments to adapt to the various types of patients’ disabilities. They also include a series of additional elements, for example footrests, designed to keep the patient in a comfortable position. Unfortunately, most of the commercial products do not allow maintaining the position of a patient foot who has no control over his lower limbs. To address this issue, customization seems to be the appropriate solution as it enables to tailor products based on predetermined features. In (Gharra et al, 2023), we have explored the use of computer vision and AI to correctly define customized parameters of the wheelchairs’ footrests. The proposed solution is based on estimating geometric properties of real shoes contours. Although this solution was accurate to some extent, its main drawback was the small amount of data that we were able to collect. For this reason, we decided to explore another approach where shoes contours data is synthetic, and Conventional Neural Networks (CNNs) are applied. This paper discusses the synthetic data approach and compares its performance to the one described in (Gharra et al, 2023).

Biomechanics and subjective measures of recreational male runners in three shoes running outdoors: a randomised crossover study

We compared biomechanical and subjective data from outdoor running in: habitual (OWN), Saucony Endorphin Racer 2 minimal (FLAT) and Nike Vaporfly 4% (VP4) shoes. We also explored relationships between comfort measures and the collected data. Eighteen male recreational runners ran three 1.5-km trials outdoors, once per shoe. The first 1.1 km was run at a self-selected comfortable (slower) speed, and last 400 m at perceived 5-km race pace (faster). A GPS-enabled smartwatch, 15-m Optojump system, high-speed camera and tibial accelerometer collected biomechanical data. Subjective data on comfort, shoe properties and overall running experience were collected using visual analogue scales (VAS) and rankings. Cadence, leg stiffness and vertical stiffness were greater in FLAT than both OWN and VP4 at the slower speed (trivial to small ES). At both speeds, footstrike angles were smaller in FLAT (small to large ES), while propulsion phase was shorter in VP4 (moderate to large ES). FLAT was ranked as the least comfortable at the slower speed and most likely to cause injury, whereas OWN as the most comfortable and least likely to cause injury. Comfort was not significantly different at the faster speed between shoes. Comfort measures were more strongly correlated to subjective than biomechanical data. The two experimental shoes generally had non-significant or small effects on running biomechanics versus OWN. As VP4 are more like traditional than minimal shoes, these were perceived as more comfortable. Running speed appeared to affect subjective measures. Speed should be considered when prescribing and selecting shoes.

Gender differences in footwear characteristics between half and full marathons in China: a cross-sectional survey

There are concerns about the risk of injuries caused by marathons in China. Since male and female runners have different injury risks, gender differences in running shoe functionality should be further complemented. A supervised questionnaire survey of 626 marathon runners was collected. The questionnaire was categorized into four sections: (1) participant profile, (2) importance of shoe properties, (3) functional evaluation of shoe properties and (4) importance ranking of shoe properties. The Mann–Whitney U test, Fisher’s exact test of cross tabulation and Chi-square test, and two-way ANOVA were used to analyze the results of this survey. The significance level was set at P < 0.05. The full marathon participants were older than the half marathon participants. There was no gender difference in the importance of shoe features to elite runners. In addition, women are more concerned about upper elasticity and have higher requirements for running shoes than men. Women were more focused on injury prevention, while men were more focused on running performance. Heel cushioning was identified by all participants as the most important running shoe feature. There were no gender differences between elite players’ demand for running shoes, but significant gender differences were found between genders at other running levels.

Effects of athletic socks with high frictional properties on in-shoe foot sliding and performance in football-specific movements

The purpose of this study was to examine the efficacy of high friction socks on in-shoe foot sliding and running performance of male footballers during change of direction movements. Twelve recreational football players (mean age 20.3 ± 1.1 years) completed a 26 m dynamic agility course at their maximum running speed. 3D kinematic and kinetic data were collected for three maximum speed 45° side-cuts, and 180° turns in two different sock conditions. Comparisons were made between a sock with a high static coefficient of friction (GripSock) and a regular sock (CompressionS). The Gripsock condition significantly increased utilized traction (COFu) and a reduction of GRF angle (GRFα) was identified during the braking phase of the side cut (COFu: + 9.3 ± 10%; GRFα: −3.1 ± 2.9%) but not in the side-cut propulsion, turn braking and turn propulsion phases. Speed perception was raised in the GripSock condition (+18 ± 30%). However, wearing a sock with high frictional properties did not significantly reduce in-shoe foot sliding in any examined direction nor did it significantly reduce running times over a functional traction course. The relationship between in-shoe traction and running performance is complex and likely dependent on the overall interaction of shoe properties and the type of athletic sock.

Integral Assessment of Antistatic Properties of Materials Used in Individual Safety Gear

The buildup of static electricity on materials is a big problem for many industrial sectors especially in situations when uncontrolled changes occur near flammable materials and liquids. Yet the combustion risks associated with static electricity, as well as the sources of fires and explosions can be controlled through the provision of proper electrostatic protection to the entire production process. Antistatic footwear is one of the elements of safety gear that protects people from static electricity at the workplace. There are three types of antistatic footwear: antistatic conductive shoes with the electric impedance of &lt;1•105 Ohms, antistatic scattering shoes with the electric impedance of 1•105-1•108 Ohms; and antistatic insulating shoes with the electric impedance of &gt;1•108 Ohms. The properties of antistatic shoes directly depend on the materials that they are made of. Thus, it is necessary to study the antistatic properties of materials to design antistatic footwear. This article aims to identify the relaxation time constant for the electric charges on the exterior, interior, and intermediate layers of shoe top materials using the integral method. The authors demonstrate that the relaxation time constant of shoe materials can vary between 4 and 40 seconds. The measured values help rationalize the selection of materials to produce antistatic footwear, the materials that can carry the charge into the ground and prevent its accumulation.

A study of consumer preferences in professional dance shoes

The article presents the results of a marketing research conducted to identify consumer preferences when choosing shoes for professional dancing. The study is part of an integrated approach to the study of the most important parameters in the design and improvement of special footwear for dancers. The survey involved artists of various dance groups, including ensembles with a worldwide reputation, such as the State Academic Choreographic Ensemble «Berezka» named after N.S. Nadezhdina, the Academic Song and Dance Ensemble of the National Guard of the Russian Federation, as well as students of specialized dance universities and schools. The respondents also included dancers who had taken part in our earlier anthropometric study. The selected method of collecting sociological information based on the use of Internet technology was carried out in the form of an interactive questionnaire located on an electronic resource. The method has a number of advantages, including the ability to fill in from a computer or mobile device online, unlimited in time, which is an important factor in obtaining full-fledged objective results among creative youth with a heavy workload in the educational and rehearsal process. According to the results of the study, the most important properties of shoes for consumers were identified, such as the materials from which various models of «jazz shoes» are made, the correspondence of the internal shape of the shoe to the individual foot, the areas of the shoe design where dancers experience discomfort during operation, as well as the most popular models of «jazz shoes». The data obtained through the survey opens up the prospect of improving the design of «jazz shoes».

Study on the preparation of nano-powder and its mechanical properties on the sole of sports shoes

Nanomaterials are a new type of material, known as "the most promising material in the 21st century", and have achieved good results in many applications. This article aims to study the preparation of nano powders and their mechanical properties on the soles of sports shoes. In this article, the liquid phase reduction method and rubber coprecipitation method are used to conduct experimental research on the preparation of nano powders. From the perspective of mechanical properties, the three mainstream materials of nano-CaCo3 filled powder, nano-powdered SiO2, and sports shoe soles include EVA, combined analysis of rubber, and TPR. The liquid phase reduction method is used to extract the nano-SiO2 powder, and the rubber coprecipitation method is used to prepare the nano-NaCO3 powder. At this time, the performance of the nano powder obtained in the test is compared with the material performance parameters used by the industrial manufacturer. Finally, the powder prepared in the experiment is used in the production of sports shoe soles to study the mechanical properties of sports shoes. The experimental results show that in the extraction process of nano-powdered SiO2 using liquid phase reduction method, the most thorough time to remove NaCl with supercritical water soaking is 1–1.5 h; only 0.5% of nano-SiO2 needs to be added, sports shoe sole EVA The tensile strength of the material can be increased to 1.3 times of the original, the fracture resistance is increased to 1.28 times, and the resilience and wear resistance of the original rubber are improved.

Running pattern changes after a 38-km trail running race: does shoe fatigue play a role?

The aim of this study was to investigate if acute impairments of the footwear midsole materials could interact with the modifications of the running patterns after a fatiguing trail running race. We hypothesized that introducing a control pair of shoes after the race, would modify running mechanics by partially correcting the alterations generated by the deteriorated properties of the shoes worn during the race. Eighteen participants ran on a treadmill at 10 km·h−1 pre- and post-race in three conditions varying the step frequency (free or fixed) or the footwear (control or personal shoes). Spatiotemporal parameters, tibial accelerations across the running conditions and shoe mechanical properties were measured. Significant changes in shoe characteristics (i.e. reduced thickness and increased stiffness) were measured after the race in the personal footwear. At free step frequency, significant changes in contact (+1.3 ± 3.5%) and flight (−19.4 ± 23.7%) times, step frequency (+2.9 ± 2.9%) and peak-to-peak amplitude acceleration at the tibia level (−3.6 ± 18%) were found. The peak-to-peak amplitude of the mediolateral axis showed a significant shoe × time interaction meaning that the control footwear could have had an impact in the running pattern. However, contrary to our hypothesis, no interaction effects were found between the changes in footwear and the changes in spatiotemporal parameters. In conclusion, impairments of shoes characteristics affect impact but not running mechanics.

Gender and leg-dominance differences in shoe properties and foot injuries in badminton: a cross-sectional survey

BackgroundWhile the roles of injury prevention and performance enhancement have increasingly been investigated for badminton footwear, there is a lack of research on gender-specific badminton footwear. The purpose of this study was to examine the gender differences in footwear demands and foot injuries in badminton.MethodsThe study was a cross-sectional survey, in which 326 recreational badminton players were recruited. The questionnaire was divided into four sections enquiring about the characteristics of (1) participant profiles, (2) importance of shoe properties (3) shoe complaints (4) and pain or discomfort in different foot regions. The Mann-Whitney U test and Wilcoxon Signed Ranks test were performed to determine the differences between genders and the differences between leg dominance, respectively. The significance level was set at 0.05.ResultsBoth males and females rated shoe fit as the most important features, followed by the overall comfort and injury protection. Females considered the shoe forefoot cushioning, comfort, breathability and colour as more important compared with the other properties, which showed distinct pattern differences from males. The shoe problem results indicated that plantar pain of the non-dominant foot was considered the most commonly reported footwear problem by both males and females. The problem of excessive arch-support on the dominant and non-dominant sides of male participants was significantly higher than females (p < 0.05). Occasional pain or frequent pain were mainly distributed in the forefoot, followed by the rearfoot and midfoot regions.ConclusionThere were small differences in footwear demand between the dominant and non-dominant sides, but several differences existed between females and males. The results from gender differences suggested that female shoes prefer a specific shoe last for better fit, rather than a modified version of male shoes. In the future, the design of badminton shoes should consider footwear demands and foot discomfort profiles in respective male and female badminton players.

Can We predict cushioning perception from the mechanical properties of shoes?

In addition to biomechanical and mechanical testing, subjective ratings of footwear such as comfort, cushioning and overall satisfaction provide valuable information for footwear design. Prior stud...

Biomechanical and perceptual cushioning sensitivity based on mechanical running shoe properties

Mechanical shoe properties impact running biomechanics, triggering subjective shoe perception. Regarding midsole hardness little is known about the minimal mechanical alteration needed to change running biomechanics and perception. Three ethylene-vinyl acetate midsoles differing in rearfoot hardness (47, 53, 57 Asker C), and peak rearfoot impact acceleration (11.65, 12.40, 12.96 g), were used to create experimental shoe conditions (softer, medium, harder), featuring differing peak rearfoot impact accelerations (12.83, 13.49, 13.95 g) when measured with insoles. Twenty-five male rearfoot runners ran on a concrete loop, while capturing ground reaction forces and lower extremity kinematics of eight valid right foot ground contacts in each shoe. Perception of shoe cushioning and shoe rebound was also assessed during these runs using a 15 cm visual analogue scale. Variable magnitude means were compared for main effects (p < 0.05) by repeated measures analysis of variance, Bonferroni post-hoc tests, and effect size estimation (ηp2). No lower limb kinematic effects were induced by the shoes. Kinetically the softer shoe significantly reduced maximal vertical loading rate 1 compared to the medium and harder shoe (131.28 to 138.40 and 139.54 bw/s). Runners significantly perceived the difference in shoe cushioning between the softer and harder shoe (6.32 to 8.06 cm). For the running shoe model in this research a difference in mechanical peak impact acceleration of 0.66 g was sufficient to elicit different biomechanical loading. To elicit different cushioning perception a mechanical difference of 1.12 g was sufficient, resulting in a maximal vertical loading rate 1 difference of 8.26 bw/s. Knowing a shoe model’s biomechanical and perceptual sensitivity to mechanical alteration allows better informed design, development, and manufacturing decisions.

Do the Mechanical Properties of Midsole Affect Body Shock and Stabilization for Lower Extremity During Running?

Objective: The purpose of this study is to examine the relation between the mechanical properties of midsole and stabilization strategies for lower extremity during running.BRBRBackground: Since stabilization strategies for a human body are to be adjusted according to the mechanical properties of the shoes, such properties of shoes that a runner wears need to be taken into consideration.BRBRMethod: Mechanical characteristics regarding the midsole cushioning properties (thickness [mm], dwell time [ms], peak acceleration [g], and energy return [%]) of each shoe were investigated by means of an impact tester. Twelve-male participated in the biomechanical experiment. They wore 12 different shoes and ran on the treadmill. To examine the relation between the mechanical properties of midsole and biomechanical variables during running, Pearson

Shoe cushioning affects lower extremity joint contact forces during running

This study evaluated the effect of running shoes with differing midsole cushioning on ankle, knee and hip contact forces during running. Joint contact forces were estimated in 40 recreational runners (28 female, 12 male) while running over ground in three shoe conditions. Shoes differed only in midsole cushioning (45, 57 and 70 Asker C). Three-dimensional kinetics and kinematics were collected during running and input to a musculoskeletal model to estimate internal axial forces at the ankle, knee and hip. Multivariate ANOVA suggested that more cushioned shoes, relative to less cushioned shoes, reduced peak joint contact forces (p < 0.01) and load rates (p < 0.01). Ankle joint contact force and load rate were reduced with increased cushioning (p < 0.01) with moderate to large effects observed between pairwise comparisons (p ≤ 0.01–0.05, dz=0.41–1.35). Cushioning effects were also observed for knee joint contact force (p = 0.03) and loading rate (p < 0.01) with load reduction only seen when comparing the soft and hard shoes (p ≤ 0.05, dz=0.41–0.44). Midsole cushioning had less of an effect on hip contact force (p = 0.31) although hip contact force loading rate was influenced by midsole cushioning (p < 0.01) with lower rates observed for soft versus medium and hard shoe comparisons (p ≤ 0.01, dz=0.41–0.62). These results suggest that increasing shoe cushioning properties ∼10–20% may benefit individuals susceptible to high loads at the ankle, and to a lesser extent knee and hip, during running.

Analysis of Insole Material Impact on Comfort During Physical Exertion

Insole material is an important factor determining the hygienic properties of shoes. It has a significant impact on health and comfort while wearing them. In this paper, the authors describe a scenario of three insole materials: flank leather, cellulose material and composite leather. Quantitative research was done using five upper materials: calfskin full and top grain leather, “buffalo” bovine leather, a soft type of grain leather, and aniline veal skin type “cool”. Qualitative analysis was performed using 3D knitted fabrics as lining. The statistical significance of the differences obtained within the groups analysed is that they prove the impact of insole material on comfort.

Influences of Athletic Footwear on Ground Reaction Forces During A Sidestep Cutting Maneuver on Artificial Turf

Background: Recreational athletes can select their desired footwear based on personal preferences of shoe properties such as comfort and weight. Commonly worn running shoes and cleated footwear with similar stud geometry and distribution are worn when performing sport-specific tasks such as a side-step cutting maneuver (SCM) in soccer and American football (hereafter, referred to as football). The effects of such footwear on injury mechanics have been documented with less being known regarding their effect on performance. Objective: The purpose of this study was to examine performance differences including peak ground reaction forces (pGRF), time-to-peak ground reaction forces (tpGRF) and the rate of force development (RFD) between football cleats (FB), soccer cleats (SOC), and traditional running sneakers (RUN) during the braking and propulsive phases of a SCM. Methodology: Eleven recreationally active males who participated in football and/or soccer-related activities at the time of testing completed the study. A 1 x 3 [1 Condition (SCM) x 3 Footwear (RUN, FB, SOC)] repeated measures ANOVA was utilized to analyze the aforementioned variables. Results: There were no significant differences (p &gt; 0.05) between footwear conditions when comparing pGRF, tpGRF, or RFD in either the braking or propulsive phases. Conclusion: The results suggest that the studded and non-studded footwear allowed athletes to generate similar forces over a given time frame when performing a SCM.

Women perception of shoe cushioning as a function of mechanical properties of footwear using a sensory trained panel method

Most of the studies investigated footwear cushioning through the quantification of impact load or running-related injuries. Few studies focused on users’ perception of footwear cushioning. Users’ perception is usually investigated in other domains like food and consumer products using the ‘Sensory Trained Panel’ method. The purpose of this study was to assess the relationship between women's perception of shoe cushioning and mechanical properties of running shoes using a sensory trained panel approach. An initial mechanical characterization enabled to select 10 shoes having a wide range of mechanical properties. Ten recreational women runners were trained to become a ‘Sensory Trained Panel.’ First, simple vocabulary and gestures were highlighted to make shoe feature definition explicit and understood by all participants. Then, participants were trained to become discriminant, repeatable and in consensus for the rating of a given shoe feature. Finally, after running with a shoe model, participants rated the shoe feature intensity on a linear scale. The order of shoe models was balanced to avoid any effect of rank, sequence and fatigue. Each footwear model was available in four copies to limit alterations of shoe properties due to repetitive use. All the shoe models were blinded to avoid any effect of shoe design on the sensory evaluation. ‘Heel penetration’ was the explicit shoe feature understood by all participants to describe shoe cushioning. Panel performances were statistically verified. A significant correlation was highlighted and enabled to predict users’ perception of heel penetration based on shoe absolute maximal compression (r = 0.86, p = 6.9 × 10−4). The sensory trained panel method seemed powerful to quantify the perception of shoe features and could be used for other purposes than correlation between sensory and mechanical data.

The influence of shoe aging on children running biomechanics

Athletic children are prone to overuse injuries, especially at the heel and knee. Since footwear is an extrinsic factor of lower limb injury risk, the aim of this study was to assess the influence of shoe aging on children running biomechanics. Fourteen children active in sports participated in a laboratory biomechanical evaluation. A new pair of shoes was provided to each participant at an inclusion visit. Four months later, the participants performed a running task and their kinematics and kinetics were assessed both with their used shoes and with a new pair of shoes identical to the first. Furthermore, mechanical cushioning properties of shoes were evaluated before and after in-vivo aging. After 4months of use, the sole stiffness increased by 16% and the energy loss capacity decreased by 18% (p<0.001). No ankle or knee kinematic adjustment was found at foot strike in used shoes but changes were observed later during stance. Running with used shoes produced a higher loading rate of the vertical ground reaction force (+23%, p=0.016), suggesting higher compressive forces under the heel and placing children at risk to experience impact-related injuries. Nevertheless, the decreased peak ankle and knee power absorption in used shoes (−11%, p=0.010 and −12%, p=0.029, respectively) suggests a lower ankle and knee joints loading during the absorption phase that may be beneficial regarding stretch-related injuries.