The effect of three alternative keyboard designs on forearm pronation, wrist extension, and ulnar deviation: a meta-analysis.
The growth of computer keyboard use in the workplace is believed to be one important determinant of the increased prevalence of work-related musculoskeletal disorders of the upper extremity (MSD-UE). One possible contributing factor to the development of MSD-UE is the flat standard keyboard, which places the forearm and wrist in biomechanically awkward postures. This meta-analysis examines the efficacy of three alternative keyboard designs, adjustable slope (AS), split fixed-angle (FA), and adjustable open-tented (AT), in reducing forearm pronation, wrist extension, and ulnar deviation. Analyses of pooled effect size from six studies indicated that the AT had a large effect on pronation (r= 0.85) and ulnar deviation whereas the FA had a large effect only on ulnar deviation (r= 0.79). The AS was found to have a large effect (r= 0.66) on wrist extension. The FA had a moderate effect on pronation (r= 0.33) and wrist extension (r= 0.30). None of these keyboards were found to have a significant effect on all three postures. This meta-analysis has implications for clinicians by providing objective information that may assist with the selection of an alternative keyboard that best reduces an identified problematic posture.
Department of Occupational Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pennsylvania 15260, USA. nab36@pitt.edu
Nancy A
NA
Baker
Erin L
EL
Cidboy
D001696:Biomechanical Phenomena; D002986:Clinical Trials as Topic; D016287:Computer Peripherals; D012090:Cumulative Trauma Disorders / Q000517:prevention & control*; D004867:Equipment Design; D006804:Ergonomics; D005542:Forearm / Q000502:physiology; D006801:Humans; D009784:Occupational Diseases / Q000517:prevention & control; D011187:Posture / Q000502:physiology; D011403:Pronation / Q000502:physiology; D014457:Ulna / Q000502:physiology; D034941:Upper Extremity / Q000502:physiology*; D014953:Wrist / Q000502:physiology