Applying the quick exposure check in the workstation design process, physical and virtual prototype assessment.

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.

Head and facial dimensions of Chilean workers for design purposes and the differences with other populations.

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.

The Average Man Does Not Exist.

Public health will improve if the prevention means take care of the variation in human characteristics and do not only consider the average or reference man [...].

Normative data for handgrip strength in Iranian healthy children and adolescents aged 7-18 years: comparison with international norms.

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.

Developments in work-related upper limb disorders (WRULD) amongst Dutch university students from 2004 to 2014.

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.

Gender inequality and sexual height dimorphism in Chile.

Chile has experienced significant improvements in its economy; thus, a secular trend in height has been observed in its population. Gender equality has also improved hand in hand with active policies addressing the gender gap in several dimensions (work, education, health) and overall economic improvement. This study examined changes in sexual height dimorphism in four samples of Chilean male and female working-age subjects and attempted to establish associations with gender equality and welfare. Sexual height dimorphism was calculated and compared with gender equality and overall welfare indicators between 1955 and 1995. Sexual height dimorphism reduction was seen to be strongly associated with greater gender equality and some general welfare indicators, such as the infant mortality rate. Gross domestic product per capita was not associated with sexual height dimorphism, but it showed significant associations with gender equality indicators. Overall, the gender gap has been reduced in Chile, which can be observed through improvements in gender equality indicators and a reduction in height dimorphism, mainly in areas associated with women's health. However, gender equality is still far behind in terms of female labour participation and women in political power, which require attention and further improvements.

Application of mismatch equations in dynamic seating designs.

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.

Educational level and its relationship with body height and popliteal height in Chilean male workers.

A secular trend in body height has been experienced in many nations and populations, hypothesized to be the result of better living conditions. Educational level has been shown to be closely associated with body height. This study examined the changes in body height and popliteal height in a group of adult Chilean male workers by age cohort and the relationship of these with educational level. The body heights and popliteal heights of 1404 male workers from the Valparaíso and Metropolitan regions of Chile were measured in 2016. The sample was grouped by level of education (primary, secondary, technical and university) and age (21-30, 31-40 and 41-50 years). Robust ANOVA and post-hoc analyses using a one-step modified M-estimation of location were conducted based on bootstrap resampling. Both body height and popliteal height increased from the older to the younger age cohort. The largest increase was from the 41-50 to the 21-30 group, with a 1.1% increase in body height and 1.7% increase in popliteal height. When educational level was introduced into the analysis there was a marked increase in both body height and popliteal height for each cohort, but only in primary- and secondary-educated workers. Despite showing an overall increase in body height and popliteal height, younger workers with the highest levels of education showed fewer differences between them than did older workers with less education. The differences were larger in the older than in the younger cohorts. Similarly, this trend was less clear in workers with higher levels of education (technical and university), probably because of a dilution effect caused by increased access to higher education by workers in the lower income quintiles.

Evaluation of conventional training in Clinical Breast Examination (CBE).

BACKGROUND: 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.RESULTSA 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.CONCLUSIONSThe 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.

Breast Cancer Detection: The Development and Pilot Study of a "Tactile Landscape" as a Standardized Testing Tool.

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.

A review of the methodology and applications of anthropometry in ergonomics and product design.

Anthropometry is a key element of ergonomic studies for addressing the problem of fitting the tasks/products to user characteristics, but there is a gap between anthropometric data and their application for designing ergonomic products and environments. This research was conducted to review the literature on the methodology and applications of anthropometry for the ergonomic design of products and environments, and to identify where further research is needed to improve its application and evaluation protocols. One hundred and sixteen papers meeting the inclusion criteria were reviewed. Although a number of anthropometric investigations have been conducted to improve the design of products/environments for different users, further research seems to be necessary, particularly for special groups, such as children, the elderly and people with disabilities. Different anthropometric measurement methods/techniques and fitting criteria are discussed regarding their applicability for various design applications. This review also highlights methodological issues (sampling considerations and prototype evaluation and testing) that should be considered in future research to ensure a user-centred approach of the design process. Practitioner Summary: A literature review was conducted on the methodology and applications of anthropometry for the ergonomic design of products/environments. This review emphasises the need for anthropometric research to design for special groups, such as children, the elderly and people with disabilities, and methodological issues that should be considered in future research. Abbreviations: 1D: one-dimensional; 2D: two-dimensional; 3D: three-dimensional; HF/E: Human Factors/Ergonomics; PCA: Principal Components Analysis; CA: Cluster Analysis; DHM: Digital Human Modelling.

New horizons in design for autonomous ageing.

The world is ageing rapidly. Between 2000 and 2050, the number of people aged ≥65 will double as a proportion of the global population, from 7% to 16%, respectively. By 2050, for the first time in human history, there will be more older people than children (aged 0­14 years) in the population. More distinctive is the tremendous increase in the oldest old aged ≥85. This challenges society to adapt, in order to maximise the health and functional capacity of older people as well as their social participation and security. Ageing is a multidimensional process of change in the physical, mental and social domain, leading to functional decline. Design thinking has embraced ageing as a topic where it can add to public health interventions. Applications of design and technology can contribute to 'autonomous ageing', for example, independent living and life style support, and can compensate for functional deficits associated with ageing. The focus is on supporting and reinforcing the reduced physical, mental, social and functional capacities of older people by applying groundbreaking, innovative design inclusive engineering methods, always starting with a human-centered integrated approach. Examples of design for geriatric giants include design for falls prevention, dementia care and integrated care. The establishment of collaborative networks between clinicians and designers, academia and industry is required to advance design for autonomous ageing.

Comparing swimsuits in 3D.

In competitive swimming, suits have become more important. These suits influence friction, pressure and wave drag. Friction drag is related to the surface properties whereas both pressure and wave drag are greatly influenced by body shape. To find a relationship between the body shape and the drag, the anthropometry of several world class female swimmers wearing different suits was accurately defined using a 3D scanner and traditional measuring methods. The 3D scans delivered more detailed information about the body shape. On the same day the swimmers did performance tests in the water with the tested suits. Afterwards the result of the performance tests and the differences found in body shape was analyzed to determine the deformation caused by a swimsuit and its effect on the swimming performance. Although the amount of data is limited because of the few test subjects, there is an indication that the deformation of the body influences the swimming performance.

A comparison between Chinese and Caucasian head shapes.

Univariate anthropometric data have long documented a difference in head shape proportion between Chinese and Caucasian populations. This difference has made it impossible to create eyewear, helmets and facemasks that fit both groups well. However, it has been unknown to what extend and precisely how the two populations differ from each other in form. In this study, we applied geometric morphometrics to dense surface data to quantify and characterize the shape differences using a large data set from two recent 3D anthropometric surveys, one in North America and Europe, and one in China. The comparison showed the significant variations between head shapes of the two groups and results demonstrated that Chinese heads were rounder than Caucasian counterparts, with a flatter back and forehead. The quantitative measurements and analyses of these shape differences may be applied in many fields, including anthropometrics, product design, cranial surgery and cranial therapy.

Hand supports to assist toilet use among the elderly.

Improving the toilet environment holds promises for increasing the quality of life for elderly and disabled persons. This is one of the goals of the Friendly Rest Room (FRR) project. The study described in this article explored the preference and use of supports in the toilet environment during the entire toilet ritual. An adjustable test frame was built with a toilet and three types of supports. Fourteen subjects were asked which positions they favoured for each support. After using all three supports, they were asked which support they found most comfortable. In general, the preferred positions depended on personal preferences more than on dimensions of the body. It was concluded that there is a preference for vertical supports for sitting down and standing up. During toilet use the side supports were equally appreciated.

Positive outcomes of participatory ergonomics in terms of greater comfort and higher productivity.

UNLABELLED: Ergonomics sometimes has a negative connotation, as it is seen to be connected to illness or guidelines that limit innovations. This paper is focused on the positive aspects of ergonomics in improvement of the working environment. It consists of a part that studies the literature on success factors in the process towards higher productivity and greater comfort, the formulation of a model and a hypothesis, which is illustrated by four cases. The model distinguishes the success factors in 'goal', 'involvement' and 'process'. GOALS: evidence is found in the literature that a positive approach has benefits in terms of shareholder value and productivity, and for comfort. Involvement: the literature shows that participation of end-users and management contributes to success. PROCESS: in the process it is essential to have a good inventory of the problems, a structured approach, a steering group responsible for the guidance, and end-users involvement in testing of ideas and prototypes. It is hypothesized that the chance of success increases by empowerment (making the end-user responsible for deciding on the next step in the process) and positive experiences of end-users with the potential improvement (end-users feel or see the benefits). The four cases illustrate that the hypothesis can be used in evaluating cases.

Anthropometry of a friendly rest room.

The use of common anthropometric tables often is not of any help when designing them for disabled people. This article addresses the advantage of first doing an observational study on the use of similar aids by disabled people. From that study, the relevant variables and critical areas can be learned. When users participate in the design process, the newly developed item probably will be innovative in comparison to just a desk research and development project. This means that a large sample is not necessary to find the potential for improvement. The study also delivers a better understanding of the fit of a particular product. This article discusses tools in anthropometry can help the designer understand the relation between dimensions and decide what should be adjustable and what should be fixed or produced in different sizes.