Ergonomic Mice: Comparison of Performance and Perceived Exertion
http://www.surl.org/usabilitynews/71/psychophysical_comparison.asp

Scarlett, Deborah
Usability News
2005

Abstract:

This study reports a psychophysical comparison of four ergonomic mouse-type devices to the standard mouse. It was hypothesized that muscle activity transferred from the distal to proximal limbs for some of the ergonomic mice may result in increased load on the shoulders and declines in target acquisition performance. Results revealed a potential tradeoff between performance and safety with the devices as participants performed the best with the standard mouse but reported more wrist exertion with this device.