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.
Baker
Nancy A
NA
Department of Occupational Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pennsylvania 15260, USA. nab36@pitt.edu
Cidboy
Erin L
EL
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