Determining the protective function of sports footwear

To reduce the risk of injury associated with foot-ground interaction during sporting activities, there is a need for adequate assessment of the protective function of sports footwear. The present objectives are to review the typical biomechanical approaches used to identify protection offered by sports footwear during dynamic activities and to outline some of the recent methodological approaches aimed at improving this characterization. Attention is focused on biomechanical techniques that have been shown to best differentiate safety features of footwear. It was determined that subject tests would be used in combination with standard mechanical techniques to evaluate footwear protection. Impact attenuation characteristics of footwear during sporting activities were most distinguished by analysis of tibial shock signals in the frequency and joint time-frequency domains. It has been argued that lateral stability and traction properties of footwear are better assessed using game-like manoeuvres of subjects on the actual sporting surface. Furthermore, the ability of such tests to discriminate between shoes has been improved through methods aimed at reducing or accounting for variability in individual execution of dynamic manoeuvres. Advances in tools allowing measurement of dynamic foot function inside the shoe also aid our assessment of shoe protective performance. In combination, these newer approaches should provide more information for the design of safer sports footwear.     

Case study of the impact of toecap type on the microclimate in protective footwear

Protective footwear plays a critical role in work effectiveness and personal safety. It exhibits special properties due to the use of protective elements and materials, but these components may deteriorate its hygienic characteristics. This paper presents a study on the influence of toecap type on the microclimate in protective footwear (ankle boots). Toecaps made of metal and of a composite polymer material were evaluated. Changes in the footwear microclimate were monitored using a thermal foot model at a perspiration rate of about 5 g/h with and without the simulated movement function. The influence of the toecap material on the microclimate in the footwear was analyzed statistically. Under conditions of simulated movement, higher temperature and relative humidity values (about 32 °C and 90%) were recorded in the toe region of ankle boots with metal toecaps as compared to composite polymer toecaps (about 29 °C and 53%, respectively). These results suggest that protective footwear with composite toecaps ensures better ventilation of the foot during work.     

Dimensional differences for evaluating the quality of footwear fit

Very few standards exist for fitting products to people. Footwear is a noteworthy example. This study is an attempt to evaluate the quality of footwear fit using two-dimensional foot outlines. Twenty Hong Kong Chinese students participated in an experiment that involved three pairs of dress shoes and one pair of athletic shoes. The participants' feet were scanned using a commercial laser scanner, and each participant wore and rated the fit of each region of each shoe. The shoe lasts were also scanned and were used to match the foot scans with the last scans. The ANOVA showed significant (p < 0.05) differences among the four pairs of shoes for the overall, fore-foot and rear-foot fit ratings. There were no significant differences among shoes for mid-foot fit rating. These perceived differences were further analysed after matching the 2D outlines of both last and feet. The point-wise dimensional difference between foot and shoe outlines were computed and analysed after normalizing with foot perimeter. The dimensional difference (DD) plots along the foot perimeter showed that fore-foot fit was strongly correlated (R(2) > 0.8) with two of the minimums in the DD-plot while mid-foot fit was strongly correlated (R(2) > 0.9) with the dimensional difference around the arch region and a point on the lateral side of the foot. The DD-plots allow the designer to determine the critical locations that may affect footwear fit in addition to quantifying the nature of misfit so that design changes to shape and material may be possible.     

Dimensional differences for evaluating the quality of footwear fit

Very few standards exist for fitting products to people. Footwear is a noteworthy example. This study is an attempt to evaluate the quality of footwear fit using two-dimensional foot outlines. Twenty Hong Kong Chinese students participated in an experiment that involved three pairs of dress shoes and one pair of athletic shoes. The participants' feet were scanned using a commercial laser scanner, and each participant wore and rated the fit of each region of each shoe. The shoe lasts were also scanned and were used to match the foot scans with the last scans. The ANOVA showed significant (p?<?0.05) differences among the four pairs of shoes for the overall, fore-foot and rear-foot fit ratings. There were no significant differences among shoes for mid-foot fit rating. These perceived differences were further analysed after matching the 2D outlines of both last and feet. The point-wise dimensional difference between foot and shoe outlines were computed and analysed after normalizing with foot perimeter. The dimensional difference (DD) plots along the foot perimeter showed that fore-foot fit was strongly correlated (R ²?>?0.8) with two of the minimums in the DD-plot while mid-foot fit was strongly correlated (R ²?>?0.9) with the dimensional difference around the arch region and a point on the lateral side of the foot. The DD-plots allow the designer to determine the critical locations that may affect footwear fit in addition to quantifying the nature of misfit so that design changes to shape and material may be possible.     

Use of SOMs for footwear comfort evaluation

Neural Computing and Applications - The comfort in footwear is essential because the foot is one of the structures of the human body that supports more weight. Moreover, consumers are demanding...     

Slip resistant properties of footwear on ice

Current research on slipperiness of footwear has mainly focused on floors and lubricated floors. Slips and falls on icy and snowy surfaces involve not only outdoor workers, but also pedestrians and the general public; and occur in cold regions and in winter season in many parts of the world. However, in comparison with the size of the problem, research on slips and falls on icy and snowy surfaces has been scarce. The objective of this paper is to explore the slip resistant properties of footwear (soling materials, roughness and hardness) on ice. The coefficients of kinetic friction of four different soling materials (synthetic rubber, nitrile rubber, natural rubber and polyurethane) were measured on ice (? 12°C). The outsole roughness and hardness were also measured. Results showed that the polyurethane soling did not perform better than synthetic rubber, nitrile rubber and natural rubber on pure hard ice (? 12°C). Soling roughness was positively correlated with the coefficient of kinetic friction. The most slip resistant soling material (polyurethane) on floors and lubricated floors may not provide sufficient slip resistance on ice.     

Slip resistant properties of footwear on ice

Current research on slipperiness of footwear has mainly focused on floors and lubricated floors. Slips and falls on icy and snowy surfaces involve not only outdoor workers, but also pedestrians and the general public; and occur in cold regions and in winter season in many parts of the world. However, in comparison with the size of the problem, research on slips and falls on icy and snowy surfaces has been scarce. The objective of this paper is to explore the slip resistant properties of footwear (soling materials, roughness and hardness) on ice. The coefficients of kinetic friction of four different soling materials (synthetic rubber, nitrile rubber, natural rubber and polyurethane) were measured on ice (-12 degrees C). The outsole roughness and hardness were also measured. Results showed that the polyurethane soling did not perform better than synthetic rubber, nitrile rubber and natural rubber on pure hard ice (-12 degrees C). Soling roughness was positively correlated with the coefficient of kinetic friction. The most slip resistant soling material (polyurethane) on floors and lubricated floors may not provide sufficient slip resistance on ice.     

Female gait patterns: The influence of footwear

The two horizontal orthogonal ground reaction forces, mediolateral (Fx) and antero-posterior (Fy), together with limb segment displacements, were recorded simultaneously during gait from 24 female subjects aged 18–29 years. Recordings were made for each subject barefoot and when wearing each of four different pairs of shoes: soft-soled, rigid-soled, medium- and high-heeled. The results showed a trend for increasing lateral stability with increasing heel height and decreasing ground contact area. This.was reflected in decreasing mean values for defined ground reaction force peaks in the medio-lateral direction at heel strike and at toe off. Limb segments displacements tended to increase with decreasing heel height and increasing shoe-ground contact area, being greatest when subjects were wearing pumps, i.e. flexible-soled, no-heeled shoes.     

Augmented reality-based design customization of footwear for children

This paper presents a systematic framework for design customization of footwear for children and identifies three modules related to shoe styling: shoe surface, shoe bottom, and accessory. A new module, shoe cloth, is created to allow a quick change of shoe appearance. Consumers can specify various design attributes in each module, including color, texture, embroidery, and shape. A prototype design system is implemented using augmented reality and sensing technologies based on the framework. This system consists of novel functions that support customization, design evaluation, and pattern development. The user can virtually put a customized shoe model on his/her foot in a video stream. The proposed framework not only facilitates evaluating products that are highly interactive with users, but also helps engage them in the design process. This work realizes the concept of human-centric design for mass customization.     

Image processing techniques for leather hide ranking in the footwear industry

The subjective assessment of finished leather hide has resulted in much argument, wasted costs and disruption of production schedules in both the tannery and leather footwear industry. Leather has attracted much research work worldwide; however, to date no objective quality assessment methodology is available, let alone an automatic assessment system. In this project, a machine-vision-based approach to grading leather hide has been developed. The image of a given castle hide was acquired using the developed machine vision system. A map of the different types of defect contours contained in the hide was extracted. Algorithms were then formulated enabling the computerization of the quarter rule, a standard method for grading leather hide in the footwear industry. Typical results from the developed grading process include the leather cuttable areas within a given hide, taking into account various types of defects, and the contour map of defects, which in fact is a vital input to any computerized shoe-part nesting system. The success of automatically grading leather hide in this project will not only provide the tanner with a means of accurately defining the price of a leather hide but also greatly assist the footwear manufacturer in the optimal nesting of irregular shoe parts within a given hide.     

Determining the mode

The complexity of computing modes and of sorting multisets is considered. Previous lower bounds are improved and an algorithm is given to determine the mode of a multiset in a number of comparisons differing from the lower bound by only a ‘lower order term’.     

Determining optimal levels of engineering characteristics in quality function deployment under multi-segment market

Customers often have various requirements and preferences on a product. A product market can be partitioned into several market segments, each of which contains a number of customers with homogeneous preferences. In this paper, a methodology which mainly involves a market survey, fuzzy clustering, quality function deployment (QFD) and fuzzy optimization, is proposed to achieve the optimal target settings of engineering characteristics (ECs) of a new product under a multi-segment market. An integrated optimization model for partitioned market segments based on QFD technology is established to maximize the overall customer satisfaction (OCS) for the market considering the weights of importance of different segments. The weights of importance of market segments and development costs in the model are expressed as triangular fuzzy numbers in order to describe the imprecision caused by human subjective judgement. The solving approach for the fuzzy optimization model is provided. Finally, a case study is provided for illustrating the proposed methodology.     

Modulation of mechanical and muscular load by footwear during catering

The BGN (Berufsgenossenschaft Nahrungsmithl und Gaststätten) reports 70% of job induced days off work to be connected with traumas of the ankle joint or overloading of the leg, knee and lower back, with an increased incidence in service areas outdoors (R. Grieshaber, personal communication). Workspace environments usually contain narrow passages, slopes or stairs and sudden changes between different surfaces. The aim of this study was to investigate the biomechanical load on the lower extremity and the low back during catering service when wearing different types of footwear. Thus, the potential for altering mechanical stress experienced during catering by variations in footwear was explored. Sixteen experienced waiters followed a course typical for a combined indoor?–?outdoor service area. Three different types of footwear were investigated using pressure distribution measurements, rearfoot goniometry and electromyography. A discriminant analysis revealed that the factors subject, shoe and surface affect rear foot movement or pressure distribution in different ways. A MANOVA demonstrated significant differences in loading parameters between footwear types. In general, these differences increased in magnitude in critical situations, such as climbing stairs or crossing slippery surfaces. The results of this study demonstrate that manipulations to footwear offer a great potential for modulating loads experienced during catering. Based on the results, the effects of constructional features are discussed. The method proposed can be applied to evaluate shoe modifications under realistic workplace conditions.     

Modulation of mechanical and muscular load by footwear during catering

The BGN (Berufsgenossenschaft Nahrungsmithl und Gastst?tten) reports 70% of job induced days off work to be connected with traumas of the ankle joint or overloading of the leg, knee and lower back, with an increased incidence in service areas outdoors (R. Grieshaber, personal communication). Workspace environments usually contain narrow passages, slopes or stairs and sudden changes between different surfaces. The aim of this study was to investigate the biomechanical load on the lower extremity and the low back during catering service when wearing different types of footwear. Thus, the potential for altering mechanical stress experienced during catering by variations in footwear was explored. Sixteen experienced waiters followed a course typical for a combined indoor-outdoor service area. Three different types of footwear were investigated using pressure distribution measurements, rearfoot goniometry and electromyography. A discriminant analysis revealed that the factors subject, shoe and surface affect rear foot movement or pressure distribution in different ways. A MANOVA demonstrated significant differences in loading parameters between footwear types. In general, these differences increased in magnitude in critical situations, such as climbing stairs or crossing slippery surfaces. The results of this study demonstrate that manipulations to footwear offer a great potential for modulating loads experienced during catering. Based on the results, the effects of constructional features are discussed. The method proposed can be applied to evaluate shoe modifications under realistic workplace conditions.     

Simulation of the behavior of the calfskin used as shoe upper material in footwear CAD

The aim of this work is to propound a mechanical behavior model for simulating the deformation of the shoe upper material in gait for footwear CAD applications. The chosen material is calfskin. The proposed material behavior for the working range is a linear elastic orthotropic model which considers large deformation and membrane and bending loading. The model was obtained from tensile tests and validated with two experiments: a test to measure the leather resistance to damage on lasting and a test that models the shoe forming process using lasts. The framework of this work is the simulation of the footwear deformation while walking for footwear computer-aided design, and these tests have been chosen because, in them, the shoe upper material is deformed in a similar way to those deformations that occur during a complete step. The tests have been simulated using the Finite Element Method. The results of this simulation show that, in most of the cases, the orthotropic model closely represents the real behavior of the leathers analyzed in this work.     

Determining the 'consumer object'

For each of us the world is a complex of dichotomous constructs clustering to form objects. Of importance to the marketing psychologist is the structure of 'consumer objects', and his aim is to determine the nature of these. The meaning of stimuli may be categorised into the denotive or functional physical aspects of being, and the connotive or emotive affectional aspects. Both are of importance in meeting consumer need. Denotive meaning is more obvious than connotive, and more covert means are necessary to uncover the latter. Examples are given of the results of such analyses of connotive being and a technique which enables a numerate assessment of the consumer object is described with an illustrative example.     

A method for dynamic measurement of the resistance to dry heat exchange by footwear

Five different types of cold protective footwear have been tested with regard to their resistance to dry heat loss (i.e. the insulation) with a new electrically heated foot model. The model is able to simulate ‘walking’ movements in order to provide a more realistic simulation of wear conditions. Thermal insulation of shoes with and without a steel toe cap was the same. The insulating properties during simulated walking movements were 10–25% lower compared with static conditions. For two of the shoe models a significantly lower insulation value for the sole area was obtained when adding a weight of 30 kg. A significant difference could also be found between the insulation values of two different sizes of one of the models. Measurements with the standard method (EN 344) correlated well with the local insulation value of the sole part of the thermal foot. Correlation with the insulation value for the whole shoe was much less, variation was bigger and ranking in terms of cold protection differed between methods. The electrically heated foot model appears to provide a reproducible, accurate and more realistic method for measuring the insulation properties of shoes than EN 344.     

The slip resistance of common footwear materials measured with two slipmeters

The slip resistance of 16 commonly used footwear materials was measured with the Brungraber Mark II and the English XL on 3 floor surfaces under surface conditions of dry, wet, oily and oily wet. Three samples were used for each material combination and surface condition. The results of a one way ANOVA analysis indicated that the differences among different samples were statistically significant for a large number of material combinations and surface conditions. The results indicated that the ranking of materials based on their slip resistance values depends highly on the slipmeters, floor surfaces and surface conditions. For contaminated surfaces including wet, oily and oily wet surfaces, the slip resistance obtained with the English XL was usually higher than that measured with the Brungraber Mark II. The correlation coefficients between the slip resistance obtained with these two slipmeters calculated for different surface conditions indicated a strong correlation with statistical significance.     

Worker evaluation of a macroergonomic intervention in a Brazilian footwear company

This article presents a macroergonomic intervention in a Brazilian footwear company and its evaluation by the workers. Using participatory ergonomics, the traditional Taylor/Ford production system was transformed into a socio-technical one and tested by 100 volunteers working during 3.5 years in a pilot production line. Multiskilling and teamwork were the major changes promoted to enlarge and enrich work and make it more flexible. The workers' evaluation pre- and post-intervention showed an increase in overall satisfaction with the work and more commitment to the results and company targets.