title: Notebook computer use on a desk, lap and lap support: effects on posture, performance and comfort.
abstract: 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.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, USA.
authors.forename: Krishna
authors.initials: K
authors.lastname: Asundi
authors.forename: Dan
authors.initials: D
authors.lastname: Odell
authors.forename: Adam
authors.initials: A
authors.lastname: Luce
authors.forename: Jack T
authors.initials: JT
authors.lastname: Dennerlein
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008328:Man-Machine Systems; D008838:Microcomputers; D011187:Posture; D013647:Task Performance and Analysis; D034941:Upper Extremity; D055815:Young Adult