Ergonomics in a Nutshell

Ergonomic design can be summarized by the following four principles:

1. Keep body in neutral position.
2. Accommodate people’s different dimensions.
3. Recognize strength and dexterity are reduced with arm extension and rotation.
4. Reduce repetitive motions.

While this seems presumptuous and overly simplistic, I think it is true.  The goal of ergonomic design is to allow interfaces to easily connect with a human. Ergonomic design is not only easier and more comfortable to use but reduces injuries and accidents. The concepts behind ergonomics are rooted in a variety of disciplines such as anthropometry, kinesiology, user psychology, environmental design and interaction design.

Ergonomic design is based on data not intuition. One must specifically avoid the mistake of designing for oneself and assuming it will be satisfactory for everyone else. Moreover, designers should not assume a design for the average person is acceptable to those at the outer ranges. Anthropometric and kinesiologic data are readily available for a wide array of demographics and provide guidance for developing designs that keep the body aligned in the neutral position and offer the appropriate range of customization required.  See for example: http://openlab.psu.edu

 

Rules of thumb have also been developed that guide designers in extending data into practical applications such as sight lines, clothing issues and extension/dexterity relationships.

Intuitive usage mapping is an important interaction design concept that can be loosely placed under ergonomic disciplines. Mapping describes the relationship between visual cues and function, such as scissor handle movement mirroring the cutting blade action. When designs are changed, traditional mapping needs to be taken into account so that a new design is approachable by those who have experience with an old design.