An aim of ergonomics is to design workplaces, systems, products, and tools,
to accommodate human variability. Paradoxically however. conventional anal
ytic techniques focus on average behaviour. This paper illustrates the impo
rtance of considering individual differences in movement kinematics through
an examination of the wrist postures adopted during the use of two differe
nt pointing devices. An implication of these data is that the introduction
of an alternate pointing device such as a trackball should be considered as
an intervention, but that the intervention should be undertaken with care
to ensure that the exposure to extreme wrist postures is reduced. The paper
concludes by describing issues related to the use of such multiple case st
udies in ergonomics research.
Relevance to industry
As well as being of different sizes, people also differ in the way they use
tools. The consequence is that the effect of an intervention may differ be
tween individuals. (C) 2000 Elsevier Science B.V. All rights reserved.