The Effects of Split Keyboard Geometry on Upper Body Postures

Details

• Personal Author:
  Chen BY ; Nathan-Roberts D ; Odell D ; Rempel D
• Description:
  Split, gabled keyboard designs can prevent or improve upper extremity pain among computer users; the mechanism appears to involve the reduction of awkward wrist and forearm postures. This study evaluated the effects of changes in opening angle, slope and height (independent variables) of a gabled (14 degrees) keyboard on typing performance and upper extremity postures. Twenty-four experienced touch typists typed on seven keyboard conditions while typing speed and right and left wrist extension, ulnar deviation, forearm pronation and elbow position were measured using a motion tracking system. The lower keyboard height led to a lower elbow height (i.e. less shoulder elevation) and less wrist ulnar deviation and forearm pronation. Keyboard slope and opening angle had mixed effects on wrist extension and ulnar deviation, forearm pronation and elbow height and separation. The findings suggest that in order to optimise wrist, forearm and upper arm postures on a split, gabled keyboard, the keyboard should be set to the lowest height of the two heights tested. Keyboard slopes in the mid-range of those tested, 0 degrees to -4 degrees, provided the least wrist extension, forearm pronation and the lowest elbow height. A keyboard opening angle in the mid-range of those tested, 15 degrees, may provide the best balance between reducing ulnar deviation while not increasing forearm pronation or elbow separation. These findings may be useful in the design of computer workstations and split keyboards. The geometry of a split keyboard can influence wrist and forearm postures. The findings of this study are relevant to the positioning and adjustment of split keyboards. The findings will also be useful for engineers who design split keyboards. [Description provided by NIOSH]
• Subjects:
  Computers Ergonomics Musculoskeletal System Occupational Health Safety
• Keywords:
  Author Keywords: Keyboard Design Computer Equipment Equipment Design Input Device Design Keyboard Operators Posture Task Performance Upper Extremities Upper Extremity Posture
• ISSN:
  0014-0139
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 10 ; OSHA Region 9 ; Washington
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  104-111
• Volume:
  52
• Issue:
  1
• NIOSHTIC Number:
  nn:20053748
• Citation:
  Ergonomics 2009 Jan; 52(1):104-111
• Contact Point Address:
  David Rempel, Ergonomics Program, Department of Medicine, University of California, San Francisco, CA, USA
• Email:
  david.rempel@ucsf.edu
• Federal Fiscal Year:
  2009
• Performing Organization:
  University of California, Berkeley
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Ergonomics
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9bc68df8da3249ee5e5e0f48354ca4c917fced72bf32f3d1437aa36939276ffe7e8fa1130a481f1e988bdd34b3d44af8872191796fe9f2e77090bb4578bd7af9
• Download URL:
  https://stacks.cdc.gov/view/cdc/216459/cdc_216459_DS1.pdf
• File Type:
  [PDF - 611.16 KB ]