This research introduces a measurable foundation for comfort. It allowed us to conduct a user study on the range in which humans prefer to operate their hands when carrying out free-hand gestures, such as for gesture recognition in combination with virtual environments. Our work suggests that human-computer interfaces should be designed within the limits of a comfort zone.
Biomechanics determines the physical range in which humans can move their bodies. Human factors research delineates a subspace in which humans can operate without experiencing musculoskeletal strain, fatigue or discomfort. We claim that there is an even tighter space which we call the comfort zone, defined as the range of postures or motions that are voluntarily adopted - as opposed to those that are exited if an alternative posture is possible. The extent of this zone can be assessed by objective measures, alleviating the need for user questionnaires.
We conducted a user study that empirically validates this conceptualization. It determined the range humans prefer to interact in when using their hands in the transverse (horizontal) plane. Not only do the results show the utility of the conceptualization of comfort, but they are also useful by themselves for designers of novel gesture interfaces and for workspace design.
Interfaces designed outside a user's comfort zone can prompt the adoption of alternative use patterns, which are often less favorable because they trade off the unnoticeable potential of injury for comfort. Designing interfaces within the limits of comfort zones can avert these risks.
Mathias Kölsch, Andrew C. Beall, and Matthew Turk.
An Objective Measure for Postural Comfort.
In HFES Annual Meeting Notes, Oct. 13--17, 2003, Denver, Colorado.