Performance and musculoskeletal loading issues

Jack Tigh Dennerlein Maria C. Yang Harvard University Reactivity 665 Huntington Ave. 1301 Shoreway Road, Suite 425 Boston, MA 02115 Belmont, CA 94002 [email protected] [email protected] REVISION: 16 October 2000 ABSTRACT Pointing devices, long an essential input tool for the graphical user interface (GUI) of desktop computers, require precision motor control and dexterity to use. Haptic force-feedback devices provide the human operator with tactile cues adding the sense of touch to existing visual and auditory interfaces. However, the performance enhancements, comfort, and possible musculoskeletal loading of using a force-feedback device in an office environment are unknown. Hypothesizing that the time to perform the task and the selfreported pain and discomfort of the task improve with the addition of force-feedback, twenty-six people total ranging in age from 22 to 44 years performed a point-and-click task 540 times with and without an attractive force field surrounding the desired target. The point-and-click movements were approximately 25% faster with the addition of force-feedback (paired t-tests, t < 0.001). Perceived user discomfort and pain, as measured through a questionnaire, were also smaller with the addition of force-feedback (t < 0.001). However, this difference decreased as additional distracting force fields, implementing a realistic work situation, were added to the task environment. These results suggest that for a given task, use of a force-feedback device improves performance as well as possibly reducing musculoskeletal loading during computer mouse use.