Evaluation of muscle activity, comfort, posture, and efficiency on using notebook with simple inclines

This study evaluated the use of external peripheral to form inclines as a means to improve the posture and minimize the muscle activity of using notebook computer. These days, users often use notebook computers in public places or external environments where no adjustable workstation is provided because of the design of laptops which are portable, lightweight, and space-saving. Furthermore, the design of laptop where the display is connected with the input device causes poorer posture to the user. Electromyography (EMG) was used to investigate the upper trapezius, cervical erector spinae, sternocleidomastoid, extensor digitorum, and extensor carpi ulnaris muscle activities when using notebook with different inclines (0°, 12°, 25°, and 30°). Head-neck posture is measured with craniocervical angle to assess the improved posture formed through applying different inclines in notebook usage. The perceived discomfort, comfort, and ease of use by the computer users were also evaluated followed by calculating the efficiency of the typing task in each incline. Based on the EMG result, the 12° induced the less overall muscle activity of the muscles examined. This result was also supported by the respondents’ subjective valuation of the inclines. Even though bigger incline offers more improved head-neck posture, it doesn’t correspond with the muscle activity result as well as the subjective valuation. Therefore, this study suggests the utilization of 12° when using laptop to improve posture and reduce the risk of any musculoskeletal disorder.This study evaluated the use of external peripheral to form inclines as a means to improve the posture and minimize the muscle activity of using notebook computer. These days, users often use notebook computers in public places or external environments where no adjustable workstation is provided because of the design of laptops which are portable, lightweight, and space-saving. Furthermore, the design of laptop where the display is connected with the input device causes poorer posture to the user. Electromyography (EMG) was used to investigate the upper trapezius, cervical erector spinae, sternocleidomastoid, extensor digitorum, and extensor carpi ulnaris muscle activities when using notebook with different inclines (0°, 12°, 25°, and 30°). Head-neck posture is measured with craniocervical angle to assess the improved posture formed through applying different inclines in notebook usage. The perceived discomfort, comfort, and ease of use by the computer users were also evaluated followed by calculating the...