earticle

영어

The purpose of this study is to compare the difference in the craniovertebral angle (CVA) on the upper trapezius muscle tone and forced vital capacity (FVC) based on the different smartphone usage durations. Twenty healthy students attending a university in South Korea participated in this study. Subjects were randomly aligned to two groups: a 5-minute and 20-minute smartphone usage group, with each group consisting of ten participants. CVA was measured using digital protractor, muscle tone using Myoton, FVC for respiratory function was measured using digital spirometery. Three measurement variables were assessed before and after the experiment. There was a significant reduction in CVA when compared within each group (p<.05), but there was no significant difference when comparing the difference before and after the experiment within groups and between groups (p>.05). Muscle tone in right and left trapezius showed no significant difference within groups and between groups (p>.05). FVC showed significant decrease in the comparisons within each group (p<.05). FVC decreased significantly in the 20-minute smartphone usage group than in the 5-minute usage group (p<.05). Therefore, during 5 and 20-minute smartphone usage, neck angle and FVC decreased. Particularly, 20-minute smartphone usage had a greater impact on FVC compared to 5-minute usage. It is suggested that maintaining proper alignment of the neck and trunk is necessary during smartphone usage.