The Effect of Key Size of Touch Screen Virtual Keyboards on Productivity, Usability, and Typing Biomechanics

Details

• Personal Author:
  Aulck L ; Bartha MC ; Johnson PW ; Kim JH ; Thamsuwan O
• Description:
  Objective: We investigated whether different virtual keyboard key sizes affected typing force exposures, muscle activity, wrist posture, comfort, and typing productivity. Background: Virtual keyboard use is increasing and the physical exposures associated with virtual keyboard key sizes are not well documented. Method: Typing forces, forearm/shoulder muscle activity, wrist posture, subjective comfort, and typing productivity were measured from 21 subjects while they were typing on four different virtual keyboards with square key sizes, which were 13, 16, 19, and 22 mm on each side with 2-mm between-key spacing. Results: The results showed that virtual keyboard key size had little effect on typing force, forearm muscle activity, and ulnar/radial deviation. However, the virtual keyboard with the 13-mm keys had a 15% slower typing speed (p < .0001), slightly higher static (10th percentile) shoulder muscle activity (2% maximum voluntary contractions, p = .01), slightly greater wrist extension in both hands (2 degrees to 3 degrees, p < .01), and the lowest subjective comfort and preference ratings (p < .1). Conclusions: The study findings indicate that virtual keyboards with a key size less than 16 mm may be too small for touch typing given the slower typing speed, higher static shoulder muscle activity, greater wrist extension, and lowest subjective preferences. Applications: We evaluated the effects of virtual keyboard key sizes on typing force exposures, muscle activity, comfort, and typing productivity. [Description provided by NIOSH]
• Subjects:
  Computers Ergonomics Musculoskeletal System Occupational Health Safety
• Keywords:
  Author Keywords: Typing Biomechanics Computer Equipment Electrogoniometer Electromyography Equipment Design Human-computer Interface Keyboards Muscle Function Posture Upper Extremities
• ISSN:
  0018-7208
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Illinois ; OSHA Region 10 ; OSHA Region 5 ; OSHA Region 6 ; Texas ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  56
• Issue:
  7
• NIOSHTIC Number:
  nn:20054794
• Citation:
  Hum Factors 2014 Nov; 56(7):1235-1248
• Contact Point Address:
  Jeong Ho Kim, Department of Industrial and Systems Engineering, Northern Illinois University, 590 Garden Road, EB240, DeKalb, IL 60115, USA
• Email:
  jaykim@niu.edu
• Federal Fiscal Year:
  2015
• Performing Organization:
  University of Washington
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Human Factors
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:c0ca7858313470d3b879e0f74510cb027e2d09187d1767c2a1c55fe3bcb37a4599006f17ea88da78d83b48467b5598b1a08a57a402c3a8402bf2862ac136b659
• Download URL:
  https://stacks.cdc.gov/view/cdc/217225/cdc_217225_DS1.pdf
• File Type:
  [PDF - 390.71 KB ]