Objective: This study tried to examine the muscle activity of the neck and trunk according to head posture changes during use of laptops. Design: Cross-sectional study. Methods: This study included nineteen young men and women. All subjects maintained each posture while practice typing on laptops for ten minutes with a 5-minute break between each posture. For the neutral head posture, the subjects practiced typing while pulling their chins down towards the Adam’s apple and were able to look at their knees while having their external auditory meatus, acromion, and greater trochanter vertical to the ground. For the natural head posture, they practiced typing while balancing their posture between extension and flexion of the cervical vertebrae by themselves without any guidelines. While a forward head posture was created by having their heads face the front horizontal to the rope hanging from the ceiling, they practiced typing with their external auditory meatus located in the place which was 5 cm in front of the vertical plane. The subjects used general word process but practiced typing with accuracy and high speed. Muscle activities were randomly measured using surface electromyography according to each postures. Results: The research result had found that muscle activity with the natural head posture was more significantly reduced than that of the forward head posture in the sternocleidomastoid muscle, upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscles (p<0.05) and that the neutral head posture was more significantly reduced than that of forward head posture in the upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscle activity (p<0.05) with significant increases in lumbar spinae muscle activity (p<0.05). Also, muscle activity with the neutral head posture significantly increased more in the sternocleidomastoid muscle and lumbar spinae than that of the natural posture (p<0.05). Conclusions: Our study results suggest that in order to prevent musculoskeletal pain, the neutral head posture with use of laptops is effective in reducing load to the shoulders and vitalizing the postural muscles.
Objective: This study tried to examine the muscle activity of the neck and trunk according to head posture changes during use of laptops. Design: Cross-sectional study. Methods: This study included nineteen young men and women. All subjects maintained each posture while practice typing on laptops for ten minutes with a 5-minute break between each posture. For the neutral head posture, the subjects practiced typing while pulling their chins down towards the Adam’s apple and were able to look at their knees while having their external auditory meatus, acromion, and greater trochanter vertical to the ground. For the natural head posture, they practiced typing while balancing their posture between extension and flexion of the cervical vertebrae by themselves without any guidelines. While a forward head posture was created by having their heads face the front horizontal to the rope hanging from the ceiling, they practiced typing with their external auditory meatus located in the place which was 5 cm in front of the vertical plane. The subjects used general word process but practiced typing with accuracy and high speed. Muscle activities were randomly measured using surface electromyography according to each postures. Results: The research result had found that muscle activity with the natural head posture was more significantly reduced than that of the forward head posture in the sternocleidomastoid muscle, upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscles (p<0.05) and that the neutral head posture was more significantly reduced than that of forward head posture in the upper trapezius, cervical vertebral spinae, and thoracic vertebrae spinae muscle activity (p<0.05) with significant increases in lumbar spinae muscle activity (p<0.05). Also, muscle activity with the neutral head posture significantly increased more in the sternocleidomastoid muscle and lumbar spinae than that of the natural posture (p<0.05). Conclusions: Our study results suggest that in order to prevent musculoskeletal pain, the neutral head posture with use of laptops is effective in reducing load to the shoulders and vitalizing the postural muscles.
Introduction Methods Results Discussion
