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Understanding of product-soft tissue interface and related discomfort is essential while designing wearable devices. Although pressure thresholds at the perception of discomfort and pain have been measured in the past, associated tissue deformation is yet to be studied. This data can provide a holistic understanding of user discomfort and be a valuable reference for ergonomic product design. Hence, in the current study, tissue deformation at discomfort and pain threshold was measured using an ultrasound indentation device at 18 landmarks for 83 Chinese adults on the head and face. Results show that deformation was higher in the facial region than the scalp and forehead, with maximum deformation in the cheek area and minimum in the forehead region for both thresholds. Also, for most landmarks, the tissue deformation data showed no significant relationship with age and Body Mass Index (BMI). Nearly half of the landmarks exhibited significant gender-based differences. Overall, the measured data showed acceptable within-session and between-session reliability.

In the past only health care professionals wore facemasks daily, but in recent times almost all citizens of many countries are expected to wear facemasks to reduce infection at work and in public. Because of SARS and now COVID-19, facemasks have become an essential personal protective equipment to fight against infectious disease. Frequent use of mask has proven to provide significant protection in reducing infections, even though there are complaints about its long-term usage. Although there are many types of masks, the surgical mask and the N95 respirator are the common ones. In this study, the surgical mask and the N95 respirator were compared with a no-mask condition. Results indicated that participants wearing the N95 respirator had the most significant thermal discomfort. The surgical mask was also significantly uncomfortable when compared to the no mask condition. Infrared thermographic results indicated that the heat retained when wearing a mask is higher than without a mask. Results of this study show the importance in mask design to have sufficient protection, comfort and fit.

Helmets are often recommended as primary safety equipment for protecting the head. Several studies have been conducted to test the effectiveness of different impact-absorbing liner materials and their response to high impact loading. The standard helmets have an impact-absorbing liner of a single material, which may not be the best design approach. Hence, the possibility of modular helmet liner design with two different materials has been explored in this study. The chapter presents a preliminary Finite element analysis (FEA) study to evaluate the performance of hard foam, soft foam and a combination of both the foams as impact-absorbing liners for helmets. The results suggest that the hard foam liner showed better performance for high impact loads, while the soft foam liner was more effective for low impact loads. The results also indicated that the modular design-based helmet liners developed using both the hard and soft foam performed better than single foam liners.

The human foot is very complex, and the development of digital models is still at its infancy. Different researches are being carried out and the results are presented in a simplified form. Furthermore, in many cases, research results from different groups vary widely because of different data samples, gender, age, etc. This chapter provides some sample data such as anthropometric data, 3D data and representation, MRI scan data, CAT scan data, and thermal data. Foot data is very important to students, researchers, and practitioners as it can enable statistical analysis, development of analysis method, and the design and development of better fitting footwear to improve foot health.

Footwear design, manufacturing, and production is entering a new phase of revolution with shorter design and manufacturing cycles. Although consumers expect shorter lead time, they are also becoming more and more demanding in terms of style, comfort, and fit. Consumers are very aware of 3D technologies and hence they expect the use of 3D technologies. Therefore, companies are starting to adopt 3D technologies in the design and development of footwear throughout the product life cycle. Nowadays, capturing the 3D shape is cheap and easy, and any products can be converted into 3D using low-cost and widely available 3D scanners. The scanned data, if required, can be modified using 3D design software. 3D design software is popular because of their ease of design, design modification, visualization, and rendering. Furthermore, footwear design developed based on 3D shoe last, enables changes of the 3D shoe last to automatically update the 3D upper design, outsole, and insole design. Functional properties of footwear such as thermal comfort, moisture management, and fit are also being considered during the design phase. In addition to footwear functional properties, creative design based on 3D enables quick design modification and visualization. The final design can then be manufactured using traditional manufacturing techniques or using a 3D printing technique. Currently, 3D printing is still evolving, and it is not the main footwear manufacturing method. 3D printing technologies have huge potential, hence more development in this area will make traditional manufacturing probably less important and, in some cases, obsolete.

The shoe last, a 3D mould for making a shoe, is, generally speaking, not well understood by shoe designers. A shoe last not only influences style and fashion, but also comfort and fit. This chapter discusses the design of shoe lasts, including definitions and shoe last main design curves. Additionally, shoe lasts of different heel height and orientations are provided, to enable designers to create new shoe lasts and eventually design shoes.

Background: Conservative treatment, Ponseti method, has been considered as a standard method to correct the clubfoot deformity among Orthopedic society. Although the result of conservative methods have been reported with higher success rates than surgical methods, many more problems have been reported due to improper casting, casting pressure or bracing discomfort. Nowadays, infrared thermography (IRT) is widely used as a diagnostic tool to assess musculoskeletal disorders or injuries by detecting temperature abnormalities. Similarly, the foot skin temperature evaluation can be added along with the current subjective evaluation to predict if there is any casting pressure, excessive manipulation, or overcorrections of the foot, and other bracing pressure-related complications.Purpose: The main purpose of this study was to explore the foot skin temperature changes before and after using of manipulation and weekly castings.Methods: This is an explorative study design. Infrared Thermography (IRT), E33 FLIR thermal imaging camera model, was used to collect the thermal images of the clubfoot before and after casting intervention. A total of 120 thermal images (Medial region of the foot–24, Lateral side of the foot–24, Dorsal side of the foot−24, Plantar side of the foot−24, and Heel area of the foot–24) were collected from the selected regions of the clubfoot.Results: The results of univariate statistical analysis showed that significant temperature changes in some regions of the foot after casting, especially, at the 2nd (M = 32.05°C, SD = 0.77, p = 0.05), 3rd (M = 31.61, SD = 1.11; 95% CI: 31.27–31.96; p = 0.00), and 6th week of evaluation on the lateral side of the foot (M = 31.15°C, SD = 1.59; 95% CI: 30.75–31.54, p = 0.000). There was no significant temperature changes throughout the weekly casting in the medial side of the foot. In the heel side of the foot, significant temperature changes were noticed after the third and fourth weeks of casting.Conclusion: This study found that a decreased foot skin temperature on the dorsal and lateral side of the foot at the 6th week of thermography evaluation. The finding of this study suggest that the infrared thermography (IRT) might be useful as an adjunct assessment tool to evaluate the thermophysiological changes, which can be used to predict the complications caused by improper casting, over manipulative or stretching and casting-pressure related complications.

Adolescent idiopathic scoliosis (AIS) is a multifactorial, three-dimensional deformity of the spine and trunk. School scoliosis screening (SSS) is recommended by researchers as a means of early detection of AIS to prevent its progression in school-aged children. The traditional screening technique for AIS is the forward bending test because it is simple, non-invasive and inexpensive. Other tests, such as the use of Moiré topography, have reduced the high false referral rates. The use of infrared (IR) thermography for screening purposes based on the findings of previous studies on the asymmetrical paraspinal muscle activity of scoliotic patients compared with non-scoliotic subjects was explored in this study. IR thermography is performed with an IR camera to determine the temperature differences in paraspinal muscle activity. A statistical analysis showed that scoliotic subjects demonstrate a statistically significant difference between the left and right sides of the regions of interest. This difference could be due to the higher IR emission of the convex side of the observed area, thereby creating a higher temperature distribution. The findings of this study suggest the feasibility of incorporating IR thermography as part of SSS. However, future studies could also consider a larger sample of both non-scoliotic and scoliotic subjects to further validate the findings.

Functions like protection and comfort are essential requirements of the footwear or orthosis. Naturally, the status of foot anatomy features, judged from both inside and skin surface, is of great significance to the effectiveness of the product. In this study, a novel method to estimate the foot anatomy structural deformation from the skin surface in three typical postures is proposed, which can effectively reveal the inner anatomy status without using CT or MRI. Technology of scanning with range sensor is adopted, and it considerably promotes the efficiency of acquisition of the foot texture model. Reverse engineering tools are used to precisely catch the anatomical landmark locations, and the relevant data is shown in the way of comparison.

Functional and smart clothing has been an up-and-coming products for fashion industry. The human model or mannequin, which is a bridge between customer's physical information and design utilization, has vital importance as primary design tool. The physiological messages of human body may have growing needs for design. The traditional geometric human models (G-model), which convey surface anthropometric data, such as shape, volume and size, may be advanced to functional model. Thermal function is highlighted in this study, based upon an emphasized potential of developing new thermal functional clothing for health enhancement and rehabilitation purpose. After reviewing theoretical basis on thermoregulation and body temperature, as well as the future application in fashion industry, the methodology of developing thermal human model (T-model) is introduced, including experiments, data pre-processing and modeling process. The T-model originated from relatively accurate 3D body scanning data has visualized and quantified skin temperature data obtained from thermographs, which may be adopted to 3D fashion design system, e.g. designing, patternmaking, pattern revision, virtual fitting and grading for functional clothing.

The synthesis and application of layered double hydroxide (LDH) is gaining impetus for developing nano-hybrids with desired functionality. They are environmentally benign and of potential use in biotechnology, pharmaceuticals, drug design, flame retardancy, separation and membrane technology, filtration, scavenging and controlled release of anions, electro-active and photoactive materials. However, there has been a limited research in wearable textile applications. In this study, magnesium–aluminium LDH nano-particles were synthesized and applied to cotton fabric to enhance mechanical, ultraviolet protection and flame retardancy properties. In addition, their cytotoxicity tests were investigated to ensure safe wearable applications. It was found that the application of this Mg–Al nano-LDH (1.5%) with reactive remazol dye (98.5%) at 2% shade improved the UV protection (UV protection factor: 20.184), enhanced flame-suppressing capacity (limiting oxygen index from 16.5 to 20.8) with significantly increased tensile strength (76.85%) of cotton.

© 2016 - IOS Press and the authors. All rights reserved. Clubfoot, known as congenital talipes equinovarus, is one of the complex paediatric foot deformity with the incidence of 1 in every 1000 live births. It consists of four complex foot abnormalities such as forefoot adductus, midfoot cavus, and hindfoot varus and ankle equinus. There are a number of surgical techniques (soft tissue releases, arthrodesis) used to correct clubfoot. However currently the conservative management (manipulation, serial casting, and braces) of clubfoot is considered as the best choice and it is widely accepted among orthopaedists. Clubfoot treated with surgical techniques might suffer various complications such as soft tissues contractures, neurovascular complications, infections, and shortening of the limbs. Although conservative method is generally considered as an effective method, it is still challenging to cure clubfoot in advance stages. Also, the classification of the initial severity of clubfoot is essential to evaluate the outcome of the treatment. In this review, the aim is to review the different types of conservative method and the assessment of clubfoot severity.

Sizing and grading are very important in footwear production, directly influencing the fit and comfort of footwear. Currently, the footwear industry relies on traditional sizing and grading systems, which vary around the world. Modern measuring technologies, such as 3D scanning and modeling, are starting to be used in footwear mass production. Sizing and grading of footwear is closely related to the sizing and grading of foot. This study investigates the application of principal component analysis (PCA) in sizing and grading methods and the influence of footwear styles based on 3D foot shapes. Three sizing and grading methods were simulated and evaluated. Results show that, compared to the traditional method, the sizing and grading using PCA method provides less modeling error, hence will result in better fit. Furthermore, the prediction error for various footwear styles are significantly different and the footwear fit near the sole could be achieved easier than instep and ankle region. This indicates that various sizing and grading rules can be applied focusing on different footwear styles in order to develop optimal sizes. Relevance to industry The proposed new sizing and grading method could benefit the footwear industry since it provides a better fit comparing to the traditional method. The influence of footwear styles on prediction error gives more detailed insights for manufacturers to further understand the fitting result when applying the different sizing and grading methods.

Most anthropometric studies generally relate to one chosen population. We wanted to assess the variations among different age groups to get a better understanding of the changes to foot shape so that footwear can accommodate these changes satisfactorily. Footwear are not differentiated between adults and elderly, even though there are footwear for children primarily because of smaller feet. Three “age groups” of males and females were scanned at different times. The heel centerline was used to register each scan. Using predetermined algorithms, the digital data were processed to obtain 49 anthropometric variables that included various length, width, girth, and flare measures. The youngest group comprised 40 female children of mean age 8.1 yrs (standard deviation [SD] = 1.48 yrs), 40 males of mean age 8.4 yrs (SD = 1.8 yrs), 40 adult females of mean age 24 yrs (SD = 3.97 yrs), 40 adult males of mean age 21.7 yrs (SD = 2.90 yrs), 40 elderly females of mean 73.3 yrs (SD = 6.8 yrs), and 40 elderly males of mean age 75 yrs (SD = 7.58 yrs). No significant differences were found between left and right foot lengths, but there were significant differences in widths, girths, and heights. Allometric equations were developed to explain the variations over the various age ranges. The findings can help understand the growth of feet and the proper fitting, especially for the elderly.

Considering the complexity of product design, designers normally use a holistic approach to create a product based on target customers and market needs. To create products, many design tools and techniques used in most cases are qualitative. Although ergonomics design principals are widely taught in many design and engineering schools, it might be limited to anthropometry, usability testing, principals and check lists. Ergonomics research data and knowledge are not presented for easy use to designers, hence ergonomics aspects are often overlooked by designers during the ideation stage. Creative design, even though commercially successful, sometimes are looked down as it may not ‘pass’ the traditional ergonomics check list. Ergonomics tools need to be developed to consider the different stages in design. Ergonomics should consider developing tools and methods with designers in mind, so that ergonomics tools can be easily adapted by them. With a clear collaboration between designers and ergonomist better creative design with imbedded ergonomics can be created.

High-heeled shoes are associated with instability and a high risk of fall, fracture, and ankle sprain. This study investigated the effects of heel base size (HBS) on walking stability under different walking speeds and slope angles. The trajectory of the center of pressure (COP), maximal peak pressure, pressure time integral, contact area, and perceived stability were analyzed. The results revealed that a small HBS increased the COP deviations, shifting the COP more medially at the beginning of the gait cycle. The slope angle mainly affected the COP in the anteroposterior direction. An increased slope angle shifted the COP posterior and caused greater pressure and a larger contact area in the midfoot and rearfoot regions, which can provide more support. Subjective measures on perceived stability were consistent with objective measures. The results suggested that high-heeled shoes with a small HBS did not provide stable plantar support, particularly on a small slope angle. The changes in the COP and pressure pattern caused by a small HBS might increase joint torque and muscle activity and induce lower limb problems.