title: Effects of keyboard tray geometry on upper body posture and comfort.
abstract: The effects of a downward-tilting (DT) keyboard tray on wrist posture, seated posture and self-assessed musculoskeletal discomfort were investigated in a field experiment. Thirty-eight professional office workers were studied. A pretest assessed how they typed using either a conventional keyboard on a desk or on an articulating keyboard tray, and with or without wrist rests. Workers were randomly allocated to a control (n = 15) or test group (n = 23) that used their existing keyboard in a DT system. A post-test was conducted 3 weeks later. Results showed no significant changes in wrist posture, seated posture or reports of musculoskeletal discomfort for the control group, and approximately 50% of typing wrist movements put the hand in a neutral zone. There were significant improvements in wrist posture, seated posture and upper body musculoskeletal discomfort for the test group using the DT system. Over 80% of typing wrist movements put the hand into a neutral zone with the DT arrangement. Reactions to using a conventional keyboard on a DT system were positive.
authors.affiliation: Department of Design and Environmental Analysis, Cornell University, NYS College of Human Ecology, Ithaca 14853-4401, USA. ah29@cornell.edu
authors.forename: A
authors.initials: A
authors.lastname: Hedge
authors.forename: S
authors.initials: S
authors.lastname: Morimoto
authors.forename: D
authors.initials: D
authors.lastname: McCrobie
mesh_terms: D000328:Adult; D016287:Computer Peripherals; D006804:Ergonomics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011187:Posture