The ergonomic fit of respiratory protective equipment (RPE) is critical for ensuring both protection and long-term usability in occupational settings. However, most respirators are designed based on outdated or foreign anthropometric data that may not represent local populations. In Chile, as in many countries without updated national databases, this mismatch can compromise comfort, effectiveness, and user compliance. This study evaluated temporal changes in facial dimensions among Chilean workers and assessed the applicability of four widely used respirator fit test panels. Two representative datasets collected a decade apart were analyzed: Dataset A (n = 474; 2013) with manual measurements, and Dataset B (n = 2016; 2024) using 3D facial scanning. Eleven facial dimensions recommended by ISO standards were examined against the LANL half- and full-facepiece panels and the NIOSH/ISO bivariate and PCA panels. Results showed significant increases in facial size, particularly among men, and a general shift toward larger facial morphologies. The NIOSH/ISO bivariate panel provided the highest coverage, while the LANL full-facepiece panel showed the poorest fit, especially among recent male participants. Gender-based differences in fit were consistent across both datasets. These findings underscore the need for updated, population-specific anthropometric references and the ergonomic redesign of respirators and fit panels. Although centered on Chile, the study has global relevance for countries that import RPE without validating fit locally. The methodology offers a scalable approach for aligning protective equipment with evolving worker characteristics, supporting international efforts to improve comfort, safety, and usability through data-informed design. These declining match rates suggest that respirator fit panels may become increasingly outdated, potentially compromising worker safety if they are not updated to reflect current population characteristics.

This study evaluates a new equation for defining maximum desk height in educational settings, comparing it with the traditional Chaffin and Anderson-based equation through biomechanical analysis. The new equation, based on 30° shoulder abduction and 35° flexion, was tested against established criteria in a quasi-experimental study involving 34 participants. Using motion capture and surface EMG, we analyzed shoulder kinematics and muscle activity during six standardized tasks performed at two desk heights. Results showed no significant differences in shoulder kinematics safety parameters between setups, while EMG data revealed consistent muscle activity patterns below 10 % MVC for both conditions. Performance metrics across tasks showed no significant differences between desk heights. Preference analysis indicated no overall significant difference between conditions, although gender-specific patterns emerged with 66 % of women preferring the proposed height. Discomfort levels were comparable between conditions. Theoretical testing of the new equation on existing databases (n: 2261 students; n: 2946 workers) demonstrated improved anthropometric fit, increasing match rates from 63 % to 94 % in students and reducing high mismatch cases from 46.7 % to 7.1 % in workers. The findings validate that the new equation maintains biomechanical safety while significantly improving anthropometric fit. This alignment between biomechanical and anthropometric criteria represents an advancement in educational furniture design, particularly relevant for contemporary educational tasks requiring forearm support.

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.

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.

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”.

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.

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.

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.

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.

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.

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.

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.

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.

Introduction There is still a need for competent breast lump detection palpation skills, especially in developing countries. Our goal is to design, develop, and establish a test to determine whether students can, by touch alone, identify and discriminate between a range of different simulated lesions at different adiposity levels. Methods Common lesions, breast cancers, and cysts were physically simulated and hidden in a test object referred to as the "tactile landscape" (TL). Ribs, intercostal muscle, and nodularity - normal anatomical features - increased their realistic complexity. Varying depths of features simulated varying degrees of adiposity. A testing protocol was created to determine the testee's ability to identify and discriminate different commonly occurring breast masses using palpation. Five experts (four breast surgeons and one general practitioner) and 20 inexperienced medical students were recruited and tested. Results were compared. Results The TL has been based on previously verified breast models and has softness similar to 53% of women's breasts and nodularity similar to 60% as assessed in a breast clinic by breast surgeons. The five experts indicated that the simulated lesions felt like those they might encounter in clinical practice and all of them identified the lesions and nonlesions hidden in the TL 100% correctly, thus indicating the value of the model. In contrast, only one student was able to identify all the lesions. One student identified none of them. The remaining students mean score was 65%. Conclusions All students but one performed poorly in comparison to the experts. This indicates that the test could be useful to test students' ability to identify and discriminate breast masses. If successful, it will add previously missing capability to the mix of assessment instruments already used, thus potentially improving clinical breast examination training and assessment.