An ergonomic evaluation comparing desktop, notebook, and subnotebook computers.

OBJECTIVE To evaluate and compare the postures and movements of the cervical and upper thoracic spine, the typing performance, and workstation ergonomic factors when using a desktop, notebook, and subnotebook computers. DESIGN Repeated-measures design. SETTING A motion analysis laboratory with an electromagnetic tracking device. PARTICIPANTS A convenience sample of 21 university students between ages 20 and 24 years with no history of neck or shoulder discomfort. INTERVENTION Each subject performed a standardized typing task by using each of the 3 computers. MAIN OUTCOME MEASURES Measurements during the typing task were taken at set intervals. RESULTS Cervical and thoracic spines adopted a more flexed posture in using the smaller-sized computers. There were significantly greater neck movements in using desktop computers when compared with the notebook and subnotebook computers. The viewing distances adopted by the subjects decreased as the computer size decreased. Typing performance and subjective rating of difficulty in using the keyboards were also significantly different among the 3 types of computers. CONCLUSIONS Computer users need to consider the posture of the spine and potential risk of developing musculoskeletal discomfort in choosing computers.

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