Nowadays, there are complications in the environments where the crutch is being used, which cause discomfort for users throughout the use and therapy period. There are many flaws in cities’ infrastructure. Using a simple search on the internet, it can be claimed that standard crutches have an array of design faults and ergonomic problems, and users seek to fix the problems with non-industrial solutions and home treatments. For this reason, various accessories for crutches are being produced, and even designers have proposed new types of crutches as replacements. However, the majority of them still didn’t pass the human-centered research procedure.

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BACKGROUND: The Quick Exposure Check (QEC) assesses four major body parts and engages users in assessing some physical interactions relevant to design in task analysis. OBJECTIVE: In this paper, we investigated the application of QEC as the ergonomic intervention to detect pre-production ergonomic design faults in the apple sorting machine by applying physical and virtual prototyping for three different tasks analysis divided into two phases (Task 1: Apple harvesting and preparation for sorting; Task 2: Sorting control and separation of waste fruits; Task 3: Transfer of separated apples). METHOD: First, the QEC questionnaire was administered while Iranian participants interacted with the machine to detect abnormal posture. Second, we redesigned a concept of the machine and assessed it with QEC by a focus group. RESULTS: Before design, the high pressure in Task 1 is on the back (dynamic), shoulder/arm, and very high pressure in Task 2, and in Task 3 on the back (static), arm/shoulder/neck, making an uncomfortable situation for posture. After redesign, we observed decreased pressures on the back/shoulder/arm in Task 1 from high to medium, in Task 3 from very high to low, and also in Task 2, this was detectable decreasing from very high pressures on the back/shoulder/arm and the high pressures on the neck to medium. CONCLUSION: Prototyping with QEC demonstrated that accurate redesigning of the machine with concentration on shifting from static tasks to dynamic or conversely, and ease of access by adjusting dimensions according to anthropometry and auxiliary products, could reduce musculoskeletal disorders.

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Feature at a Glance: Welcome to the special issue on anthropometry! This discussion will cover a range of differently sized topics to fit your interests. De Bruin and Castelluci discuss the problems of designing school furniture that fits students, noting that “Regarding School furniture dimensions, students are usually exposed to furniture with fixed dimensions, which makes it almost impossible to adjust to the ‘growing’ anthropometrics along their school life and neither does it accommodate multidimensional fit very well.” Griffin et al. discuss developing an “understanding [of] body dimensions in relation to how a body functions, moves, and changes” that “is fundamental to creating compatible wearable products” for aging women. Alemany et al. discuss 4D scanning, observing that “This technology is able to capture the human body surface in motion at high frequency with a high resolution” and offers “an enormous potential to advance in ergonomic design and biomechanics.” Bradtmiller describes the “nearly infinite combination of head/facial characteristics” and that “This combination of traits allows us to recognize unique individuals but increases the challenge of designing head and face products that fit a wide variety of individuals with a relatively small number of sizes”.

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Human computer models represent a useful tool for investigating the human body response to external static/dynamic loads or for human-centred design. Articulated Total Body (ATB) models are the simplest human multibody models, where body segments are represented by ellipsoids joined at skeletal articulations. Over the years, regression models on both living subjects’ and cadavers’ data have been developed to predict body segments properties. These models are affected by two main limitations: the only inputs are the subject’s weight and height, not considering that for the same combination different morphologies can exist; secondly, regression analyses were performed over a specific population not including peculiar morphologies (under-weight or obese). A novel methodology for developing anthropomorphic ATB models is here presented: a statistical shape model able to predict the external geometry of the human body from a limited set of anthropometric measurements was implemented and body segments were obtained by segmentation; the respective inertial properties were computed from volumes, assuming a constant density value. The properties of this new anthropomorphic ATB model were compared to those calculated by GEBOD (Generator of Body Data), a well-known programme for ATB data calculation. A virtual population of twenty subjects was analysed: with reference to the inertial properties the most relevant differences occurred at the abdomen and the thighs segments (60% relative error), while the trunk, the shoulder and the calves represent the most critical areas for the geometry reconstruction (50 mm average error). The significance of these outcomes was investigated performing multibody simulations with various scenarios.@en

BACKGROUND: An appropriate match between a product and its end-users requires anthropometric data, which show variations among different countries. Proper Personal Protection Equipment (PPE) fit is key for safety and comfort. Chile had no head and facial anthropometric data available in order to design face/head PPE. OBJECTIVE: To describe face/head anthropometric characteristics of Chilean workers. Additionally, this study compared those dimensions against other populations (United States (US), South Korea and China). METHODS: An anthropometric survey involving 21 measures was conducted between September 2013 to May 2016 using stratified sampling. The measurements were based on ISO/TS 16976-2 and ISO 15535 to ensure the highest standards possible, and a total of 474 workers, aged from 18 to 66 years old, participated in the survey. RESULTS: The biggest differences were in Neck circumference, Weight, Nose breadth, Nose protrusion, Bitragion chin arc, Face length, Subnasale-sellion length, Face width, Bigonial breadth and Bitragion subnasal arc. Head length of Chileans were longer than Chinese and South Korean ones, but shorter than US Head length. Chilean Head breadth is smaller than Chinese and South Korean ones. Chileans Face length was the largest observed. Face width of Chileans was smaller than US and Chinese ones. Gender specific differences were also observed in the inter-country comparisons. Chilean males had larger anthropometric dimensions than females. CONCLUSION: Chilean Head and face dimensions differed significantly when compared against US, South Korean and Chines Head and Face dimensions. Chileans have longer and narrower faces with wider mouths, with a head size in between the US and Asian heads. Face and head PPE for Chileans should use dimensions in the current paper in order to ensure proper fit.

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BACKGROUND: Anthropometrics is very important when ensuring a physical match between end users and product or workstations. OBJECTIVES: The purpose of this study are twofold, to provide anthropometric data for the design of products and to examine the secular changes in the adult Chilean workers in a period of more than 20 years. METHODS: Nineteen anthropometric measurements from two samples from 1995 and 2016 were compared using independent t-test (95% confidence interval), where additionally absolute and relative differences were calculated. RESULTS: The secular trend observed for Stature is characterized by an increase average of 20mm and 10.5mm per decade for females and males, respectively. There is a positive secular trend for both genders, which is observed for most of the selected body measurements. The most pronounced increases were onWeight, Shoulder breadth, Body mass index, Popliteal height; Buttock-popliteal length and Hip width. CONCLUSIONS: Segmental dimensions that experienced a positive secular trend, together with Weight and Stature, are highly correlated with seating design, addressing the need to review products targeting Chilean adult workers, such as public transport seats, office furniture or industrial workplaces.

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Anthropometry is critical for product and workplace design. Highly prevalent, office work is associated with sedentarism and physical discomfort due to prolonged sitting. Dynamic seating (alternating across sitting, perching, and standing) has been suggested as an alternative to overcome those problems. The current study tested a large sample of anthropometric data for mismatch levels against national and international office furniture standards using dynamic seating as a framework with traditional and perching mismatch equations, applied to three recommended dynamic seating components. Dimensions present in the standards used did not match the majority of the sample. For sitting, seat width and depth individually presented the lowest levels of match, as well as under cumulative fit of all office furniture dimensions. However, these were alleviated when incorporating adjustability. Perching was shown to be generally impeded given commercially-available chair height options. Limitations in state-of-the-art perching equations are discussed, and two new models are proposed as design alternatives. Further research should focus on testing the criteria presented in this research through discomfort and objective measures.

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BACKGROUND: Former studies on work-related upper limb disorders (WRULD) within university education report substantial prevalence rates. In this study, developments in WRULD amongst students in the period 2004-2014 were investigated. Our findings can be a benchmark for future studies, in particular when there are major societal changes as in the case of the COVID-19 pandemic. OBJECTIVE: Differences in time (academic year), how long students have been studying (year of studying), relations with computer time and societal changes were points of interest. METHODS: 2254 students (average age 20.0 years) responded to a questionnaire on WRULD. Students experiencing complaints were further questioned about the severity of complaints and associated body locations. RESULTS: The average percentage of students experiencing complaints was 57%. The highest prevalence rates and severity scores were found in the first and last recorded academic years. The neck, shoulder, back and wrist were most often indicated. The prevalence of complaints raised from the 1st (49%) to the 4th (75%) year of studying. Two seriousness measures showed highest scores in the 5th/6th/7th year of studying. Relations were found between both the prevalence and seriousness of complaints with reported computer time. CONCLUSIONS: After an initial decreasing trend from the academic year 2006/2007 to 2010/2011 there was an increase in WRULD amongst students from 2010/2011 to 2013/2014. Limiting financial and study time factors may have played a role. Structural attention for WRULD prevention and risk factors seems to be effective in reducing prevalence and severity of WRULD. This seems to be even more necessary due to recent COVID-related changes in the students' lives.

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The use of 3D anthropometric data of children’s heads and faces has great potential in the development of protective gear and medical products that need to provide a close fit in order to function well. Given the lack of detailed data of this kind, the aim of this study is to map the size and shape variation of Dutch children’s heads and faces and investigate possible implications for the design of a ventilation mask. In this study, a dataset of heads and faces of 303 Dutch children aged six months to seven years consisting of traditional measurements and 3D scans were analysed. A principal component analysis (PCA) of facial measurements was performed to map the variation of the children’s face shapes. The first principal component describes the overall size, whilst the second principal component captures the more width related variation of the face. After establishing a homology between the 3D scanned face shapes, a second principal component analysis was done on the point coordinates, revealing the most prominent variations in 3D shape within the sample.

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Background: Grip strength is an essential component of physical fitness. The objective of this study was to develop normative handgrip strength data for Iranian healthy boys and girls comparing their handgrip strength with international reference values. Methods: Handgrip strength was measured in 2637 healthy children/adolescents (1391 boys and 1246 girls), aged 7–18 years, using a standard adjustable Jamar hand dynamometer (Model 5030 J1, Sammons Preston Rolyan, Bolingbrook, IL, USA). Body mass (kg) and stature (cm) were measured and body mass index was computed in kg/m². The sample was stratified by gender, age, and hand preference. Results: Handgrip strength increased with age and was considerably higher in boys than in girls for all age groups (p < 0.001). Grip strength had a parallel and linear growth for both genders until the age of about 11 years and showed a steeper upward slope in boys than in girls thereafter. The findings of the current investigation were significantly different from those of the previously published normative data, especially for boys over the age of 12 years and girls in the age range of 7–18 years (p < 0.001). This difference was mainly in such a way that the Iranians had lower handgrip strength. Conclusions: The differences between present results and those of similar available in the literature in this field emphasize the significant role of using normative data specific to a particular population in research or clinical settings.

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The facial fit of respirators is crucial for determining how effectively respirators may protect users from exposure to airborne contaminants, when their use is required in the workplace. In the Chilean market, all the respirators available have been designed and manufactured using foreign regulations. The aim of this research was to determine the facial dimensions in a sample of Chilean workers (users or potential users of respiratory protective equipment) and the possible mismatch between their anthropometric characteristics and the respirator fit test panels proposed by Los Alamos National Laboratory (LANL) and National Institute for Occupational Safety and Health (NIOSH). An anthropometric survey that included 11 measurements was conducted, based on ISO/TS 16976–2 and ISO 15535 to ensure the highest standards possible, and a total of 474 workers (female: 229, male: 245), aged 18–66 years old participated in the survey. The anthropometric measurements were then contrasted with the fit test panels used in LANL (for half and full facepieces) and NIOSH (Bivariate and Principal component analysis (PCA)), to verify the level of mismatch. The results showed that LANL panels presented a level of mismatch of 11.8% and 21% for the half-facepiece and the full-facepiece, respectively. Considering the NIOSH bivariate and PCA panels, 4.6% and 4.4% of the sample remains without an assigned cell, respectively. It can be concluded that the LANL panels for half and full facepieces do not match the facial dimensions of the Chilean working population. The panels developed by NIOSH and considered by the ISO/TS 16976–2 (bivariate and PCA), are applicable to the Chilean working population. Relevance for the Industry: This research provides anthropometric measurements of Chilean workers, to determine the dimensions for half- and full-facepiece respirators, which are currently not available. The NIOSH or ISO fit test panels, as opposed to LANL panels, should be used when manufacturing respirators for Chilean workers.

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A 3D head and face scan data can be usefully applied in the ergonomic design of a wearable product such as an oxygen mask or a virtual reality (VR) headset to support the safety as well as comfort for a certain amount of a target population. This study is aimed to develop analysis and design methods of an ergonomic facial wearable products (e.g., pilot oxygen mask, VR headsets) based on numerous 3D face scan data (366 faces and 2,299 heads) through the template registration and the finite element (FE) analysis methods to predict the contact pressure between the face and a product. The application of the FE analysis on numerous 3D images to find an optimal form of a product is a novel approach in product design. The proposed methods on contact pressure analysis could be usefully applied for wearable products, which fit body parts.@en

Designing products that closely interact with the human body can be quite challenging. Think for example about wearables like helmets, (Virtual Reality-) goggles, masks, garments, sports braces, or shoes. We are all unique individuals and this requires designers to carefully consider the great variety of human body shapes and come up with smart ways of accommodating this variety in such products through the use of sizing systems, adjustable parts, or flexible materials. We introduce ‘Mannequin’, a new tool for the DINED- platform. Through this tool, we want to make 3D anthropometry accessible for engineers, designers, and ergonomists by providing an intuitive interface for exploring 3D body shape variation and creating 3D design manikins. In the open data spirit of DINED, Mannequin can be freely used for both research and commercial purposes.@en

Anthropometry has been used extensively for designing safe and sustainable products and workplaces. However, it is common that designers need straightforward guidelines and dimensions, which they often lack, for specific design situations. Anthropometric data are usually presented in tables that summarize percentile values, separated by gender, of a specific population, which makes it difficult for designers to generate applications for mixed populations, such as industrial settings. Using a recently collected anthropometric database of Chilean workers (male and female), international standards of dimensions for working height, depth, and ideal manual handling height are tested with univariate and bivariate methods. Alternative dimensions are presented for both adjustable and non-adjustable designs. Additionally, procedures to combine samples, and for knowing how many users match with a particular design are explained using the sample data. As expected, adjustable designs proved to match with higher numbers of users, while non-adjustable dimensions recommended by ISO presented low levels of matching. Furthermore, the non-adjustable design achieved 83% of matching, which increased to the desired levels (90%) with the inclusion of a 50 mm increase platform. Finally, the Z-Score equation proved to be a useful tool to know the percentages of the population that are matched with a particular design dimension. Relevance for the industry: Dimensions for working height, depth, and ideal manual handling heights, which are currently not available, are provided for Chilean workers. A method to determine the matching percentage in a population is explained, in order to assess matching probabilities when having only summarized anthropometric tables and the dimensions for the design itself.

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3D body scanning has been used broadly including digital human modeling, simulation, ergonomic product design, and so forth. This research used template-registered faces of 336 Koreans in order to use them to design an oxygen mask that provides good fit to Korean faces. The finite element analysis method is applied onto the template-registered faces to predict the contact pressure of a mask design onto different faces. The average and variation of the estimated contact pressure values among all the Korean faces were analyzed for evaluation of the appropriateness of a mask design for Koreans. The proposed method can be usefully applied to find an optimal shape of wearable products for a specific target population.

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The study investigated the extent to which electronic voting is accessible to Dutch voters, especially the visually impaired, those with low literacy, and the elderly. Together with the different user groups, a series of electronic interfaces were developed and simulations of a vote-printer were built to run tests on large numbers of participants. The interface consisted of a card reader, a touchscreen and a printer; audio support was available via a headset. For participants with disabilities, the independent variables were visual impairment and low literacy. For elderly participants, the independent variable was age. All participants were asked to make specific choices on the screen and to check the printed result for their choice. As reference, they were asked to vote using the current Dutch ballot paper/red pencil system. The criteria used to determine the accessibility of both systems was: does the printed ballot match the intended vote? The vote-printer significantly increased independent voting by the visually impaired, however this was not seen for the low-literacy group. For the elderly, the use of a vote-printer with electronic interface is equally as accessible as the current paper ballot. All three groups reported using a vote-printer with electronic interface to be easier than the current paper ballot. The study confirmed that co-creating with intended users in the early conceptualization phase is key.

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Clinical Breast Examination (CBE) is the examination of a women's breasts by a healthcare professional, such as a breast surgeon, family physician or breast-care nurse who is trained to recognise many different types of abnormalities and warning signs in the breast [1]. CBE is particularly important in rural areas and developing countries who have limited access to technology such as mammography. CBE needs to be taught to health professionals like any other clinical skill used by medical professionals in the workplace. CBE in part involves palpation of the breast, that is, determining by touch which breast lumps are normal and which are suspicious in feeling. The gold standard for assessing tactile skills in CBE is seeing whether students can accurately identify and discriminate between different breast lumps also known as masses (IDBM) on actual patients in a clinical setting. However, this is not practical in a medical education setting. Usually the testing methods 'go through the motions' of feeling the breast as part of CBE. So the students' technique is examined either using unrealistic simulation models or using an intimate examination associate (IEA), an actor/volunteer who permits students to examine their intimate body parts such as breast or genitals for teaching purposes. These volunteers do not have any abnormalities so this teaching does not include the actual detection of suspicious lumps.We undertook a study of clinical skill with 10 medical students to examine different methods of assessing novice student clinical skills after a brief training in CBE. OBJECTIVES: This study aims to evaluate the effectiveness of current training and assessment of novice students in CBE and their capacity to identify and discriminate breast masses (IDBM) on actual patients. METHODS: We assessed each student's IDBM ability in an actual clinical situation, a breast clinic with a mixture of eight IEAs and one real patient with a large, easily palpable, putative breast cancer. We recruited 10 clinically inexperienced medical students, who were trained for 30 minutes by two breast surgeons using an IEA. Students were tested in a simulated clinical setting, a breast clinic where each examined 4 IEAs and one patient. The students were blind to who was the real patient and who was an IEA. Patients were examined by a breast surgeon in private prior to the commencement in the study. The breast surgeon recorded any clinical finding on the patients during the initial examination. The surgeon coached each patient on how to mark the students and showed the patient their results so the patients had a benchmark. After each examination was finished the students had four different assessments: 1) patients marked each student, 2) students were independently proctored - that is, marked by an expert, 3) students recorded their clinical findings and 4) students recorded how confident they were that they had the correct findings. Results from different kinds of student assessments were compared. RESULTS: A chi-square test for independence between true positive or negative masses versus student-assessed positive or negative masses was not significant at alpha = .05. This means that there was no statistical association in the indication of positive or negative presence of masses versus whether such masses were actually present or absent. By comparison, experts (breast surgeons) were able to detect normal and abnormal breast masses by palpation alone 100% of the time and rate their confidence level as 'certain'. Unlike the experts, student self-reported confidence was unrelated to their competence score (CS). Proctoring was inversely related to the students' CS. CONCLUSIONS: The main conclusion is that novice students do not seem to be able to accurately detect breast masses in a clinical setting even after training. On the basis of these results, we believe that a comprehension component in the current CBE testing is needed in addition to the current methods of testing.

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Three-dimensional scanning technologies have brought great opportunities in ergonomic and product design education as well as research. Not only the anthropometric size but also the shape and posture of the human, form of a product, or interactions between the human and product obtained based on the 3D scanning have been usefully applied in product design. This chapter introduces a number of educational and research cases, which have been performed at the Faculty of Industrial Design Engineering at Delft University of Technology. First, as ergonomics plays a big role in the product design process, but in a different and advanced way than before, we have broadly applied the emerging 3D scanning technology in our design education and research. Because the topic of “ergonomic design based on 3D scanning” have been taught in our education, the number of students who are using 3D human scans for their course work and/or graduate project has increased considerably. Some of our successful cases will be introduced in this chapter. Second, from the 3D scanning practices in our education, we concluded there is a need of a 3D scanner, especially for the human hand, that is both quick and accurate but is also capable of scanning parts that are normally hard to cover. Multiple final master projects have contributed to the development of a working prototype of an accurate and low-cost 3D hand scanner. Finally, based on our experience, techniques, methods, software, and relevant information that can support design education based on 3D human scans will be discussed.

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Obtaining an appropriate match between a product and its end-users requires anthropometric data, which are typically outdated and show variations among different countries. Chile had its anthropometric data taken nearly 20 years ago, thus they are probably outdated. The purpose of this article is to describe some anthropometric characteristics of Chilean workers. An anthropometric survey involving 27 measures and five calculated body dimensions was conducted in 2016. The measurements were based on ISO 7250 and ISO 15535 to ensure the highest standards possible, and a total of 2946 workers, aged from 18 to 76 years old, participated in the survey. The results showed that Chilean workers have smaller dimensions than Dutch and US workers but have larger dimensions than South Koreans. The data presented in this article constitute the most up-to-date anthropometric dataset describing the dimensions of Chilean workers. Practitioner Summary: In Chile, women are smaller and weigh less than men, and both of these populations have high body mass index (BMIs). In addition, the Chilean population exhibits substantial differences compared with other international adult populations. The data presented in this article should be used as a reference when designing for Chilean workers.

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