Abstract
Direct touch displays can improve the human–computer experience and productivity; however, the higher hand locations may increase shoulder fatigue. Palm rejection (PR) technology may reduce shoulder loads by allowing the palms to rest on the display and increase productivity by registering the touched content and fingertips through the palms rather than shoulders. The effects of PR were evaluated by having participants perform touch tasks while posture and reaction force on the display were measured. Enabling PR, during which the subjects could place the palms on the display (but were not required to), resulted in increased wrist extension, force applied to the display and productivity, and less discomfort, but had no effect on the self-selected positioning of the display. Participants did not deliberately place their palms on the display; therefore, there was no reduction in shoulder load and the increased productivity was not due to improved hand registration. The increased productivity may have been due to reduced interruptions from palm contacts or reduced motor control demands.
Abstract
Practitioner Summary: Since placing the palms on a touch display would decrease shoulder loads and provide for improved registration with the touched content, a laboratory study assessing the effects of palm rejection technology was performed. With palm rejection enabled, task speed increased and self-reported discomfort decreased even though palms were rarely placed on the display.
Acknowledgements
The authors' primary contributions included conception, design, interpretation and writing (Matt J. Camilleri and David M. Rempel), joint centre and moment computations and editing (Jeffrey Fujimoto), and posture and display position computations and editing (Ajith Malige).