The effect of keyboard keyswitch make force on applied force and finger flexor muscle activity
- 1 August 1997
- journal article
- clinical trial
- Published by Taylor & Francis in Ergonomics
- Vol. 40 (8), 800-808
- https://doi.org/10.1080/001401397187793
Abstract
The design of the force-displacement characteristics or ‘feel’ of keyboard keyswitches has been guided by preference and performance data; there has been very little information on how switch ‘feel’ alters muscle activity or applied force. This is a laboratory-based repeated measures design experiment to evaluate the effect of computer keyboard keyswitch design on applied finger force and muscle activity during a typing task. Ten experienced typists typed on three keyboards which differed in keyswitch make force (0·34, 0·47 and 1·02 N) while applied fingertip force and finger flexor electromyograms were recorded. The keyboard testing order was randomized and subjects typed on each keyboard for three trials, while data was collected for a minimum of 80 keystrokes per trial. No differences in applied fingertip force or finger flexor EMG were observed during typing on keyboards with switch make force of 0·34 or 0·47 N. However, applied fingertip force increased by approximately 40% (p < 0·05) and EMG activity increased by approximately 20% (p < 0·05) when the keyswitch make force was increased from 0·47 to 1·02 N. These results suggest that, in order to minimize the biomechanical loads to forearm tendons and muscles of keyboard users, keyswitches with a make force of 0·47 N or less should be considered over switches with a make force of 1·02 N.Keywords
This publication has 9 references indexed in Scilit:
- Keyboard Reaction Force and Finger Flexor Electromyograms during Computer Keyboard WorkHuman Factors: The Journal of the Human Factors and Ergonomics Society, 1996
- Investigation of Applied Forces in Alphanumeric Keyboard WorkAihaj Journal, 1994
- Workplace ergonomic factors and the development of musculoskeletal disorders of the neck and upper limbs: A meta‐analysisAmerican Journal of Industrial Medicine, 1991
- Ergonomics considerations in hand and wrist tendinitisThe Journal of Hand Surgery, 1987
- Roles of glabrous skin receptors and sensorimotor memory in automatic control of precision grip when lifting rougher or more slippery objectsExperimental Brain Research, 1984
- Factors influencing the force control during precision gripExperimental Brain Research, 1984
- Keyboard entryApplied Ergonomics, 1971
- ELECTROMYOGRAPHIC INVESTIGATIONS DURING TYPEWRITINGErgonomics, 1958