Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

The effect of keyboard key spacing on typing speed, error, usability, and biomechanics: part 1.

Authors
Pereira-A; Lee-DL; Sadeeshkumar-H; Laroche-C; Odell-D; Rempel-D
Source
Hum Factors 2013 Jun; 55(3):557-566
NIOSHTIC No.
20042901
Abstract
OBJECTIVE: In this study, we evaluated the effects of key spacing on a conventional computer keyboard on typing speed, percentage error, usability, and forearm muscle activity and wrist posture. BACKGROUND: International standards that specify the spacing between keys on a keyboard have been guided primarily by design convention because few studies have evaluated the effects of key spacing on productivity, usability, and biomechanical factors. METHOD: Experienced male typists (N = 37) with large fingers (middle finger length > or = 8.7 cm or finger breadth of > or = 2.3 cm) typed on five keyboards that differed only in horizontal and vertical key spacing (19 x 19 mm, 18 x 19 mm, 17 x 19 mm, 16 x 19 mm, and 17 x 17 mm) while typing speed, percentage error, fatigue, preference, extensor carpi ulnaris and flexor carpi ulnaris muscle activity, and wrist extension and ulnar deviation were recorded. RESULTS: Productivity and usability ratings were significantly worse for the keyboard with spacing of 16 x 19 mm compared with the other keyboards. Differences on these measures between the other keyboards were not significant. Muscle activity tended to increase in the left forearm and decrease in the right with decreasing horizontal key spacing. There was also a trend for left wrist extension to increase and left ulnar deviation to decrease with decreasing horizontal key spacing. Reducing vertical key spacing from 19 to 17 mm had no significant effect on productivity or usability ratings. CONCLUSIONS: The study findings support key spacing on a computer keyboard between 17 and 19 mm in both vertical and horizontal directions. APPLICATIONS: These findings may influence keyboard standards and the design of keyboards.
Keywords
Computers; Computer-equipment; Ergonomics; Equipment-design; Human-factors-engineering; Keyboard-operators; Biomechanics; Posture; Standards; Electrophysiological-measurements; Musculoskeletal-system; Work-capacity; Task-performance; Men; Humans; Extremities; Muscle-function; Fatigue; Testing-equipment; Measurement-equipment; Author Keywords: key pitch; keyboard design; tool design; switch; wrist posture; electromyography
Contact
David Rempel, Ergonomics Program, University of California, Berkeley, 1301 S. 46th Street, UC RFS Building 163, Richmond, CA 94804
CODEN
HUFAA6
Publication Date
20130601
Document Type
Journal Article
Email Address
david.rempel@ucsf.edu
Funding Type
Grant
Fiscal Year
2013
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-T42-OH-008429; B20130801
Issue of Publication
3
ISSN
0018-7208
Source Name
Human Factors
State
CA
Performing Organization
University of California, Berkeley
TOP