Are fized computer input device activation forces suitable for all users?
Muscle twitch contraction and 1/2 relaxation times are important measures of the physiological state of the muscle. We hypothesize that mouse button click durations may be associated with muscle twitch contraction times (the duration of the contraction plus the half relaxation time). Eighteen adult males, sixteen adult females and fourteen children between 5-8 years old performed a series of point-and-click tasks with three mice which had different button activation forces (0.65N, 0.85N and 1.05N). During the point-and-click task the time to press and release the mouse button was measured. In addition, muscle twitch durations (contraction time +1/2relaxation time) were measured from the finger flexor muscles from 30 adult females, 34 adult males and derived for children based on the literature. Across all subjects, mouse button-click duration significantly increased with every 0.2 N increase in mouse button activation force. The total twitch durations for the adult males and females were roughly 7 ms longer than their respective mouse button click durations indicating the measures were relatively similar in magnitude. However, unlike the adult data, the child data indicated that the mouse button click duration were longer (not shorter) than the total twitch durations by 43 ms. The results indicate that current “one design fits all approach to mouse button activation forces has different effects on children and adults, this raises the question of the suitability of a one design fits all design philosophy. In addition, to evaluate the suitability of input device activation forces for different statured users, a viable objective measure may be to select activation forces where the mouse button-click durations approach the combined contraction and half relaxation durations of involuntary muscle twitches.
PW Johnson S Komandur RL Storch
University of Washington, Department of Environment and Occupational Health Sciences,Seattle, WA 981 University of Washington, Department of Industrial Engineering, Seattle, WA 98195, USA
国际会议
17th World Congress on Ergonomics(第十七届国际人类工效学大会)
北京
英文
1-6
2009-08-09（万方平台首次上网日期，不代表论文的发表时间）