J.F.M. Molenbroek

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.

Anthropometry of elderly people in the Netherlands; research and applications.

In order to fill the need for useful ergonomic data on elderly people, an anthropometric investigation has been conducted in several old peoples homes in The Hague, the Netherlands. Twenty-five functional body dimensions of 822 elderly people were measured using methods based on international standards. The results have been used to compile a set of ergonomic recommendations and are being implemented in an existing CAD-model called ADAPS. This paper presents and discusses the findings of the investigation, and compares them with the English results from Loughborough and with the German DIN 33402. The mean value and standard deviation of unshod stature and weight were 157.1 cm (8.9 cm) and 63.7 kg (14 kg) respectively for 197 male and 625 female elderly. For the male sample, these values were 165.6 cm (8.2 cm) and 67.3 kg (13 kg); and for the female sample, they were 154.3 cm (7.2 cm) and 62.6 kg (14 kg), respectively. There were no large differences from published figures from the UK and Germany, but there are with figures on younger people.

The effect on sitting posture of a desk with a ten-degree inclination using an adjustable chair and table

By means of continuous recording of the positions of the trunk and head, an investigation was carried out to examine the effect of the Erasmus office-desk - a desk with a 10 degrees inclination - on sitting posture whilst reading and writing, sitting in an adjustable chair at an adjustable table. The posture assumed by a person who is doing mixed reading and writing work at a table with the Erasmus office-desk is more upright than the posture of the same person doing the same work without the desk. This applies for both the head and the trunk. The average position of the trunk was changed from 26.0 degrees to 18.2 degrees when working with the desk placed on the table. The moment of force caused by gravity is proportional to the sine of the angle. Therefore the change of angle results in a decrease of the average moment of force on the back at L5-S1 of 29%. The largest individual decrease found was 86%. The average change of the position of the head was changed from 38.5 degrees to 29.6 degrees , resulting in an average decrease of the moment of force, on C7-T1, of 21%. The largest individual decrease was 51%. Lateroflexion of the back was less often assumed when the subjects were using the desk. The posture assumed by the subjects when they were doing writing work only was generally more upright when working at a desk with a 10 degrees inclination than when working at a flat desk. Marked differences were found between the postures of the subjects. The change of posture while using the desk also showed marked differences for each subject individually.

Applying different equations to evaluate the level of mismatch between students and school furniture.

The mismatch between students and school furniture is likely to result in a number of negative effects, such as uncomfortable body posture, pain, and ultimately, it may also affect the learning process. This studys main aim is to review the literature describing the criteria equations for defining the mismatch between students and school furniture, to apply these equations to a specific sample and, based on the results, to propose a methodology to evaluate school furniture suitability. The literature review comprises one publications database, which was used to identify the studies carried out in the field of the abovementioned mismatch. The sample used for testing the different equations was composed of 2261 volunteer subjects from 14 schools. Fifteen studies were found to meet the criteria of this review and 21 equations to test 6 furniture dimensions were identified. Regarding seat height, there are considerable differences between the two most frequently used equations. Although seat to desk clearance was evaluated by knee height, this condition seems to be based on the false assumption that students are sitting on a chair with a proper seat height. Finally, the proposed methodology for suitability evaluation of school furniture should allow for a more reliable analysis of school furniture.

Anthropometry and design for the disabled: Experiences with seating design for the cerebral palsy population

In recent years increased emphasis has been placed on designing improved technical aids for physically disabled people. One limiting factor has been the lack of anthropometric resource data that is appropriate for use with individuals with specific disabilities, such as cerebral palsy. The purpose of this study has been to examine briefly why the anthropometric needs of disabled individuals may be different from able-bodied individuals, and to develop an anthropometric data resource that can be used in the design of seating and mobility devices for a specific segment of the disabled population. Ninety-four variables were obtained from each subject in a sample of 133 cerebral palsied individuals. Both qualitative and quantitative factors were assessed and measured, respectively. The qualitative factors are used to define the unique characteristics of the sample group. Twenty quantitative variables are analysed and the results presented in a tabular format. Eleven of the 20 variables are not available from existing able-bodied anthropometric sources, but were deemed important for use in the design process for the study population. The paper references a supplementary manual which contains the complete results, including descriptive statistical tables and scattergram plots. The paper also discusses the implications for application of the results, possible limitations of their use, and precautions that should be observed when considering extrapolations to other populations of disabled people.

Anthropometric data of children for non-specialist users

In a pilot study, 33 anthropometric variables were measured on 633 children aged 0-5.5 years. The variables where chosen on the basis of international standards and on the results of preliminary analysis of accidents. Methodical aspects of this pilot study are presented in this paper, followed by two applications: anthropometric aspects of current regulations for cribs, playpens and toys; anthropometric aspects in the selection of wheelchairs for children. The paper concludes with a discussion on how to present anthropometric data for non-special users.

RECOMMENDATIONS FOR THE ASSESSMENT AND DESIGN OF YOUNG CHILDREN'S BICYCLES ON THE BASIS OF ANTHROPOMETRIC DATA

Childrens bicycles are the product most often involved in leisure accidents to children. One of the possible reasons for this might be a lack of fit between the dimensions of the bicycle and the dimensions of the child. In a project entitled KIMA-1, some 33 dimensions of 279 children (aged 2.5-5.5 years) were measured at seven infant welfare centres in the province of Zuid, Holland. These data were used to compare dimensions of children with dimensions of bicycles. Furthermore, the requirements regarding bicycle dimensions laid down in product safety acts of different countries were compared with both the results of KIMA-1 and some bicycles available in shops. It is concluded that maximum product safety and comfort of the bicycle are achieved when the bicycle is fitted to the dimensions of the child. Enhancement of this fitting process can be achieved by relating the dimensions of the bicycle to the stature rather than to the age of the child. The comparison of the KIMA-1 data to the dimensions laid down in product safety acts led to the conclusion that Dutch children are larger than the population on which the safety dimensions are based. Furthermore, secular changes in body dimensions call for a revision of the relevant safety dimensions in 10-15 years.

The effect of secular trends in the classroom furniture mismatch: support for continuous update of school furniture standards.

In order to create safer schools, the Chilean authorities published a Standard regarding school furniture dimensions. The aims of this study are twofold: to verify the existence of positive secular trend within the Chilean student population and to evaluate the potential mismatch between the anthropometric characteristics and the school furniture dimensions defined by the mentioned standard. The sample consists of 3078 subjects. Eight anthropometric measures were gathered, together with six furniture dimensions from the mentioned standard. There is an average increase for some dimensions within the Chilean student population over the past two decades. Accordingly, almost 18% of the students will find the seat height to be too high. Seat depth will be considered as being too shallow for 42.8% of the students. It can be concluded that the Chilean student population has increased in stature, which supports the need to revise and update the data from the mentioned Standard. Practitioner Summary: Positive secular trend resulted in high levels of mismatch if furniture is selected according to the current Chilean Standard which uses data collected more than 20 years ago. This study shows that school furniture standards need to be updated over time.

Investigations to Develop a Fully Adjustable Intelligent Toilet for Supporting Old People and Persons with Disabilities - The Friendly Rest Room (FRR) Project

The FRR (Friendly Rest Room) project creates and evaluates prototypes of a more user friendly intelligent toilet for old persons and for persons with disabilities. Additionally, applicable knowledge regarding needs and wishes of old and/or disabled persons and their care persons are documented. In this paper the user driven research approach, ethical aspects and the iterative user centred design process are outlined. First results from user tests of lighting, human computer interface and preferred seating heights are described.

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.