Anthropometric characteristics of Chilean workers for ergonomic and design purposes

Synthesis and validation algorithm followed by a weighting procedure to create a detailed anthropometric dataset for the German working-age population

For the German working-age population no publicly available and detailed anthropometric raw dataset exists, although several studies have collected anthropometric datasets. Unfortunately, the publication of raw data may be restricted by data usage regulations. This study presents a synthesis and validation algorithm to create a virtual copy of an already existing dataset. A detailed anthropometric dataset from a regional epidemiological public-health study in Germany was used for the synthesis and validation algorithm. Results revealed only minor deviations within the validation process. Compared to the original dataset, the virtual dataset was statistically almost identical. In a next step, the virtual dataset was weighted to approximate nationally representative values. In summary, the computed unweighted and weighted virtual data can be published without restrictions and used for ergonomic designing. Furthermore, the synthesis and validation algorithm is suitable for the generation of virtual copies and can be applied to other detailed anthropometric datasets.

Occupational Safety and Health for Adult Saudi Arabian Women: Utilizing National Anthropometric Data

In the last five years, the female labor force has increased rapidly in Saudi Arabia. This is due to the new government's vision to empower women. For many decades, Saudi females were excluded from working in certain fields due to cultural restrictions. Nowadays, Saudi women are not only joining the service workforce but are currently employed in more physically demanding careers, such as manufacturing and military jobs, which were previously dominated by males. It becomes necessary to design workplaces, tools, and equipment to safely accommodate the female physical attributes, which include body dimensions. This study presents the anthropometric measurements of Saudi Arabian adult females. In total, 504 female subjects aged 20-70 participated in the study. Thirty-eight body measurements, including weight and triceps skinfold, were taken in sitting and standing postures. The main contribution of this study is to provide a national anthropometric database of Saudi females, which is very limited, especially for females in the age groups under study. The availability of such data will allow foreign and local manufacturers to design usable and safe products and workspaces for a wide range of Saudi adult females. The findings reveal that there are no significant differences in the body dimensions of Saudi females across all age groups, except for stature height, eye height, chest depth, skinfold (mm), sitting height, buttock-knee length, and hip breadth. The study also reveals that Saudi females' body sizes are different from other Asian, Middle Eastern, and British nations, which invalidates the assumption of using other nations' body measurements to estimate Saudis' body measurements. Utilizing the supermarket cashier workstation to assess the appropriateness of commercial station fit for Saudi females' body dimensions, the results underscore the crucial role of anthropometric measurements in addressing differences between product design and the unique body dimensions of Saudi females. The identified anthropometric mismatch highlights potential risks, emphasizing the threat to the working safety of Saudi females. Moreover, the data can be used by health professionals as a base to evaluate the health of Saudi adult females. Descriptive statistics and extreme values are determined. The data are presented in standard anthropometric tables.

Assessing Spatial User Experience for Design Guidelines: A Comparative Study of Outpatient Waiting Rooms With Conventional Versus Modern Features

OBJECTIVES

Identify waiting room design features that are most appreciated by outpatients and their companions in conventional and modern waiting rooms. Evaluate if end users evaluate the environment differently from experts and in what aspects. Provide evidence-based design guidelines that orient designers and healthcare managers.

BACKGROUND

Built environments are relevant in patients' evaluation of overall healthcare service. For outpatients, waiting frequently consumes the largest amount of time; thus, waiting room interior design has great potential to enhance their experience.

METHODS

This study compares perceptions of two types of waiting rooms-conventional and modern-based on the spatial user experience (SUE) model. In the first stage of the study, we compared user evaluations of conventional waiting rooms (n = 137) and modern waiting rooms (n = 426) with respect to the eight SUE model dimensions using multigroup structural equation modeling. In the second stage, an expert ergonomist and two professional interior designers assessed both types of waiting rooms.

RESULTS

Results showed that modern waiting rooms were perceived to be significantly better in all SUE dimensions. We also found experts' evaluations were overall consistent with users' perceptions. Discrepancies were only found in temperature perception, signage evaluation, and spatial appreciation.

CONCLUSIONS

Participants valued modern style waiting room features such as good quality signage, use of armchairs and sofas, a controlled environment, and decoration. We suggest involving end users in the design process to respond to their needs and promote a positive experience. Finally, we provide easy-to-adopt design guidelines to improve patients' waiting room experience.

Elderly-friendly indoor vertical dimensional layout method based on joint mobility

INTRODUCTION

The vertical dimensional arrangement of space is primarily influenced by the reachable range of human fingertips. Currently, this dimensional layout analysis concentrates solely on static body dimensions based on Farley's principle. However, the joint mobility of the elderly population has diminished, necessitating the identification of the factors influencing the age-friendly spatial vertical dimension layout through experimentation.

METHODS

A random sample of 62 adults and 62 elderly individuals were selected to measure the joint mobility of 8 groups with varying comfort levels. The measurement results were analyzed using an independent sample t-test with SPSS software.

RESULTS

The joint mobility of the elderly group exhibited a notable difference from that of the adult group across distinct comfort gradients. A significant reduction in the range of motion of all joints in the elderly was observed. The findings suggest that the reachable range of the upper limbs of the elderly should be considered in conjunction with joint mobility. We propose a vertical dimensional layout method for residential spaces that accommodates the joint mobility of elderly users.

CONCLUSION

The joint mobility of the elderly is significantly deteriorating, and the traditional vertical spatial layout method cannot adequately support the daily life of the elderly. It is essential to integrate the joint mobility factor into the vertical dimensional layout design process. In this paper, we propose an elderly-friendly vertical spatial dimension layout method. It offers a reference for subsequent planning of elderly-friendly vertical dimension layout.

Improving Tractor Safety: A Comparison between the Usability of a Conventional and Enhanced Rear-Mounted Foldable ROPS (FROPS)

Tractor rollover is the main cause of both fatal and non-fatal injuries in agriculture. The foldable rollover protective structure (FROPS) can help to prevent these injuries. However, in many cases, the FROPS is left in a folded-down position. Human factor and rear-mounted FROPS technical characteristics influence operators' behavior in roll-bar handling. To improve the FROPS's comfortable use, the prototype of an enhanced handling system was developed, and its usability was tested and compared with a conventional FROPS. Usability was assessed with 93 novice tractor users through an ad hoc questionnaire (investigating perceived effort, time demand, the posture adopted and satisfaction) and observations (investigating effectiveness and efficiency) during lowering and raising tasks. For both tasks, the participants perceived significantly less effort, less physical discomfort, a higher level of satisfaction and less time demand while operating the enhanced FROPS. Observations showed that the critical issues that emerged for the conventional FROPS were eliminated by adopting the developed and implemented handling system. The developed handling system showed itself to be usable and effective in making the FROPS easier and safer to be operated.

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.

Evaluation of the External Ear and Head Anthropometric Dimensions Among Fars and Turk Workers for the Ergonomic Design of the Earmuffs

Background: Anthropometry plays an important role in the ergonomic design of hearing protection equipment and its compatibility with the dimensions of the external ear and head of workers. Few studies have been conducted on the dimensions of the external ears and heads of workers in Iran with different ethnicities. Objectives: This study aimed to collect the anthropometric dimensions of the external ear and head of workers of two prominent ethnicities of Iran for the ergonomic design of earmuffs. Methods: Following a cross-sectional design, this study was performed on 300 male workers (150 Turk and 150 Fars) aged 20 - 60 years. Anthropometric dimensions of the external ear and head were measured using a spreading caliper, camera, tripod, and tape measure. Photographs were analyzed using Digimizer V5.3.5 software, and data were analyzed using SPSS 21. Results: The mean age of Turk and Fars workers was 33.51 ± 5.41 and 33.95 ± 6.05 years, respectively. The ear shape was oval in more than half of the male workers of the two studied ethnicities. There was a positive correlation between anthropometric dimensions of head and ears in both ethnicities. The 95th percentile of the length and width of the pinna in Fars and Turk workers was larger than the average dimensions of inner ring earmuffs. Conclusions: Hearing protection devices available in the Iranian market should be examined to fit the ear dimensions of different Iranian ethnicities. External ear anthropometric data obtained from this study can be used to redesign the earmuffs in Fars and Turk male workers.

Accuracy of the Resting Energy Expenditure Estimation Equations for Healthy Women

Background: There exist several prediction equations for the estimation of resting energy expenditure (REE). However, none of these equations have been validated in the Chilean female population yet. The aims of this study are (1) to determine the accuracy of existing equations for prediction of REE and (2) to develop new equations in a sample of healthy Chilean women. Methods: A cross-sectional descriptive study was carried out on 620 Chilean women. The sample showed an age range between 18 and 73 years, a body mass index average of 28.5 ± 5.2 kg/m², and a prevalence of overweight and obesity of 41% and 33.2%, respectively. REE was measured by indirect calorimetry (REE_IC), which was used as the gold standard to determine the accuracy of twelve available REE prediction equations and to calculate alternative formulas for estimation of REE. Paired t-tests and Bland–Altman plots were used to know the accuracy of the estimation equations with REE_IC. At the same time, multiple linear regressions were performed to propose possible alternative equations. The analyses were carried out by age groups and according to nutritional status. Results: All the equations showed a tendency to overestimate REE, regardless of age or nutritional status. Overall, the Ireton-Jones equation achieved the highest mean percentage difference from REE_IC at 67.1 ± 31%. The alternative new equations, containing variables of body composition, reached a higher percentage of classification within ±10% of REE_IC. Conclusions: The available equations do not adequately estimate REE in this sample of Chilean women. Although they must be validated, the new formulas proposed show better adaptation to this Chilean sample.

Secular changes in the anthropometrics of Chilean workers and its implication in design

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.

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.