Introduction to and objective of this guide
Designers, production planners, testers and designers of the technical environment and members of standards committees often face questions such as this: "How can I design my product to be used comfortably and safely?"
In order for products with interfaces between human beings and the technical environment to be designed optimally and so as to be ergonomically comfortable and safe, design of the environment must take full account of the biological and physiological needs of the human body. Values for dimensions of the human body (anthropometric data) are an essential aspect of such design.
Human beings interact with products and technical environments in every area of the modern world. It is rare however for these products and environments to be adapted to the individual user. Consequently, anthropometric data and the dimensions derived from them are applied in practice in a wide range of areas, such as the design of production facilities and other working premises, public spaces (such as the interiors of vehicles, furnishings in schools), workstations on machinery, everyday and protective clothing, footwear, technical medical devices, and in many other areas. At the same time, these dimensions also serve as a basis for the development of computer-aided simulation systems (CAD systems, "computer manikins").
If design work is conducted without reference to anthropometric data or is based on the wrong data, the result can easily be that short people are able to reach an actuator without problems whereas tall people have to bend down considerably.
In order for the technical environment to be designed with consideration for safety and comfort, this guide is intended to provide designers, production planners, testers, designers of technical environments and products, and members of standards committees with essential guidance on selecting and applying data concerning the dimensions of the human body, and on avoiding foreseeable incorrect application of these data.
Are you involved in design work?
Whenever a human (working) environment and/or a product with which human beings come into contact are developed/designed, an interface is created between the human being and the (technical) environment. Anthropometric data are required in such cases for optimum design.
Anthropometric data are required and used particularly often for the design of clothing, workstations, personal protective equipment, and human-machine interfaces. Besides the design of products to be ergonomic and comfortable, consideration must often also be given to aspects of occupational safety. Since anthropometric data presents certain risks of being used incorrectly – examples are the selection of incorrect body dimensions, use of the body dimensions of an inadequate user population (e.g. of unsuitable age), or failure to consider clothing – knowledge of the circumstances enables you to avoid such incorrect use of anthropometric data.
Experience in the field has shown that the technical facilities for personal adjustment of office workstations (facility for adjustment of office chairs and desks) already enable the workstation to be adjusted perfectly to the requirements of the individual user.
Personal protective equipment (PPE) is usually available in systems of sizes and types. In this case, the variability of body dimensions is taken into account by the development of optimized size categories, which ensure the best possible fit for the individual user. Many components of personal protective equipment, such as respiratory masks, are in direct contact with the human body, and clothing etc. thus has less of an influence upon the body dimensions used.
The design of machinery and production areas is often much more complex. The following aspects must therefore be considered when anthropometric data are used:
- The body dimensions of individual users vary, owing to the need for mobility during the work processes.
- Multiple body dimensions are usually relevant.
- Each product is intended not only for one specific user, but for a frequently changing group of users.
- Requirements relating to safety and optimum ergonomics must frequently be combined, and addressed in the correct sequence or hierarchy.
Are you involved in standardization work?
Where standards refer to body dimensions stated in other standards, it is advisable for the referring standard not to state the actual numerical values found in the standards referred to, but to refer to them indirectly by reference to the standard itself (sliding reference), in order to allow for updates of the values in the latter.
Standards bodies develop standards into which anthropometric data are frequently incorporated, owing to the purpose of the standard. All aspects which must be taken into account by designers during the design of products should if possible be considered during the development of the standard.
Many standards make reference to other standards in force. This is advantageous in the interests of standardization of dimensional data. Where anthropometric data are concerned however, the actual numerical values may change from one generation to the next (see Up-to-dateness of anthropometric data). For this reason, basic standards governing anthropometric data (e.g. DIN 33402-2; CEN ISO/TR 7250-2) are updated at irregular intervals without these changes being adopted directly in standards drawing upon them. As a result, users may be presented with conflicting anthropometric data, despite the reference to the standard being correct (for example: two different values for the lowest body height to be considered). For this reason, it is preferable to refer only to the standard as such, for example by stating that the 5th percentile of the body height to CEN ISO/TR 7250-2 is to be used. A similar procedure is recommended for the creation of formulae containing fixed values for body dimensions (for example, for a situation in which a helmet is worn: "50th percentile of the body height stated in CEN ISO/TR 7250-2 + 35 mm" rather than "1,714 mm + 35 mm"). This makes the standard more difficult to read and requires the up-to-date values to be taken from the standard referred to, but has the advantage of guaranteeing that uniform data are used.