Representing older and disabled people in virtual user trials: data collection methods

Ergonomics and aging: A bibliometric analysis

BACKGROUND: Despite the prevalence of publications focusing on the trends of the studies on ergonomics, the information of the aging focused studies within these publications is limited. OBJECTIVE: This study aims to provide general information regarding the trends of the studies on ergonomics and aging by using bibliometric analysis techniques and to provide a general view regarding to the development of this field. METHODS: The bibliometric data of the publications on ergonomics and aging were retrieved from the WOS Database and analysed by using the Bibliometrix extension of the R Packet Programme. For the visualisation of the bibliometric data, the Vosviewer programme was used. RESULTS: Analysis results of the 405 papers published between the years of 1979 and 2020 show that main themes were digital human modelling, design for all, workplace ergonomics, transport and vehicle design, kitchen design, human factors, care and vision in old age. CONCLUSIONS: The content of the studies on ergonomics and aging changed from basic elements of ergonomic design for older people to the investigations about computer-aided applications and the effect of the developing technology. Therefore, it can be said that the studies on ergonomics and aging are changing parallel to the development of the technology.

Quantitative Analysis Of User Interfaces For Large Electronic Home Appliances And Mobile Devices Based On Lifestyle Categorization Of Older Users

Background/Study Context: The increasing longevity and health of older users as well as aging populations has created the need to develop senior-oriented product interfaces. This study aims to find user interface (UI) priorities according to older user groups based on their lifestyle and develop quality of UI (QUI) models for large electronic home appliances and mobile products.

METHODS

A segmentation table designed to show how older users can be categorized was created through a review of the literature to survey 252 subjects with a questionnaire. Factor analysis was performed to extract six preliminary lifestyle factors, which were then used for subsequent cluster analysis. The analysis resulted in four groups. Cross-analysis was carried out to investigate which characteristics were included in the groups. Analysis of variance was then applied to investigate the differences in the UI priorities among the user groups for various electronic devices. Finally, QUI models were developed and applied to those electronic devices.

RESULTS

Differences in UI priorities were found according to the four lifestyles ("money-oriented," "innovation-oriented," "stability- and simplicity-oriented," and "innovation- and intellectual-oriented"). Twelve QUI models were developed for four different lifestyle groups associated with different products. Three washers and three smartphones were used as an example for testing the QUI models.

CONCLUSION

The UI differences of the older user groups by the segmentation in this study using several key (i.e., demographic, socioeconomic, and physical-cognitive) variables are distinct from earlier studies made by a single variable. The differences in responses clearly indicate the benefits of integrating various factors of older users, rather than single variable, in order to design and develop more innovative and better consumer products in the future. The results of this study showed that older users with a potentially high buying power in the future are likely to have higher satisfaction when selecting products customized for their lifestyle. Designers could also use the results of UI evaluation for older users based on their lifestyle before developing products through QUI modeling. This approach would save time and costs.

Modeling people with motor disabilities to empower the automatic accessibility and ergonomic assessment of new products

Virtual User Models (VUMs) can be a valuable tool for accessibility and ergonomic evaluation of designs in simulation environments. As increasing the accessibility of a design is usually translated into additional costs and increased development time, the need for specifying the percentage of population for which the design will be accessible is crucial. This paper addresses the development of VUMs representing specific groups of people with disabilities. In order to create such VUMs, we need to know the functional limitations, i.e. disability parameters, caused by each disability and their variability over the population. Measurements were obtained from 90 subjects with motor disabilities and were analyzed using both parametric and nonparametric regression methods as well as a proposed hybrid regression method able to handle small sample sizes. Validation results showed that in most cases the proposed regression analysis can produce valid estimations on the variability of each disability parameter.

Supporting the development of inclusive products: the effects of everyday ambient illumination levels and contrast on older adults' near visual acuity

Current older adult capability data-sets fail to account for the effects of everyday environmental conditions on capability. This article details a study that investigates the effects of everyday ambient illumination conditions (overcast, 6000 lx; in-house lighting, 150 lx and street lighting, 7.5 lx) and contrast (90%, 70%, 50% and 30%) on the near visual acuity (VA) of older adults (n = 38, 65-87 years). VA was measured at a 1-m viewing distance using logarithm of minimum angle of resolution (LogMAR) acuity charts. Results from the study showed that for all contrast levels tested, VA decreased by 0.2 log units between the overcast and street lighting conditions. On average, in overcast conditions, participants could detect detail around 1.6 times smaller on the LogMAR charts compared with street lighting. VA also significantly decreased when contrast was reduced from 70% to 50%, and from 50% to 30% in each of the ambient illumination conditions.

PRACTITIONER SUMMARY

This article presents an experimental study that investigates the impact of everyday ambient illumination levels and contrast on older adults' VA. Results show that both factors have a significant effect on their VA. Findings suggest that environmental conditions need to be accounted for in older adult capability data-sets/designs.

Effects of age, gender, and target location on seated reach capacity and posture

OBJECTIVE

The aim of this study was to investigate the effects of age, gender, and target location upon arm reach capacity and posture.

BACKGROUND

The older adult population is growing in number. Their specific needs must be better understood to improve the design of work and life spaces.

METHOD

Thirty-eight adults, divided into four groups according to their gender and age, participated in the experiment. They were asked to reach 84 targets located in a large space defined according to their anthropometry and reach capacities. Reach capacities and postures were analyzed.

RESULTS

On average, older participants showed shorter maximal reach distances (by 4.8% of upper limb length) as compared with younger participants. No gender difference was found for maximum reach distance. Age also had significant effects on reach posture, especially through its interactions with target azimuth. Older participants tended to use their trunk less whenever possible. Reduced neck and trunk/seat axial rotations were observed for the older participants when the target deviated from the sagittal plane. They compensated by a greater rotation of the pelvis with respect to the seat.

CONCLUSION

Older people's reach capacities should be taken as references, rather than those of younger people, in order to accommodate a wider range of the population.

APPLICATION

These results can be used to improve the arrangement of living spaces and work spaces for older people.

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.