Notebook computer use on a desk, lap and lap support: effects on posture, performance and comfort.
Asundi K; Odell D; Luce A; Dennerlein JT
Ergonomics 2010 Jan; 53(1):74-82
This study quantified postures of users working on a notebook computer situated in their lap and tested the effect of using a device designed to increase the height of the notebook when placed on the lap. A motion analysis system measured head, neck and upper extremity postures of 15 adults as they worked on a notebook computer placed on a desk (DESK), the lap (LAP) and a commercially available lapdesk (LAPDESK). Compared with the DESK, the LAP increased downwards head tilt 6 degrees and wrist extension 8 degrees . Shoulder flexion and ulnar deviation decreased 13 degrees and 9 degrees, respectively. Compared with the LAP, the LAPDESK decreased downwards head tilt 4 degrees, neck flexion 2 degrees, and wrist extension 9 degrees. Users reported less discomfort and difficulty in the DESK configuration. Use of the lapdesk improved postures compared with the lap; however, all configurations resulted in high values of wrist extension, wrist deviation and downwards head tilt. STATEMENT OF RELEVANCE: This study quantifies postures of users working with a notebook computer in typical portable configurations. A better understanding of the postures assumed during notebook computer use can improve usage guidelines to reduce the risk of musculoskeletal injuries.
Biomechanics; Computer-equipment; Computers; Ergonomics; Injury-prevention; Laboratory-testing; Motion-studies; Muscles; Musculoskeletal-system; Musculoskeletal-system-disorders; Posture; Risk-analysis; Risk-factors;
Author Keywords: lapdesk; laptop; musculoskeletal disorder; posture; upper extremity
Department of Environmental Health, Harvard School of Public Health, Boston, MA
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Harvard University, Boston, Massachusetts