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http://dx.doi.org/10.21598/JKPNFA.2019.17.1.57

The Effects of Long-Term Smartphone Usage Time and of Stretching on Stiffness, Concentration, and Visual Acuity  

Ko, Min-Gyun (Department of Physical Therapy, Graduate School of Sahmyook University)
Song, Chang-Ho (Department of Physical Therapy, Sahmyook University)
Yu, Jin-Ho (Department of Physical Therapy, Chunnam Techno University)
Publication Information
PNF and Movement / v.17, no.1, 2019 , pp. 57-68 More about this Journal
Abstract
Purpose: This study is an investigation of the effects of long-term smart phone usage and of stretching on muscle stiffness, concentration, and visual acuity. Methods: Forty healthy young adults voluntarily participated in the study and were measured for muscle stiffness, concentration, and visual acuity before smartphone usage and after 30 minutes, 60 minutes, and 90 minutes of smartphone usage. The participants were randomly allocated to the intervention group (n=20) and the control group (n=20). Five minutes after the stretching exercise and eye exercise intervention, the participants were remeasured. Results: After long-term smartphone usage, increases in muscle stiffness and concentration were statistically significant (p<0.05), whereas decreases in visual acuity were statistically significant (p<0.05). After the stretching exercise and eye exercise intervention, muscle stiffness significantly decreased (p<0.05) and visual acuity significantly increased (p<0.05). Concentration, according to the stretching exercise and eye exercise intervention, showed no significant pre- or post-test difference. Conclusion: The results from this study indicate that long-term smartphone usage effectively improved concentration but increased muscle stiffness and decreased visual acuity. Appropriate stretching and eye movement during long-term smartphones usage should mitigate the effects on muscle stiffness and visual acuity. Furthermore, smartphones should be considered an effective tool for concentration training when coupled with the development of appropriate applications.
Keywords
Smartphone; Muscle stiffness; Concentration; Visual acuity; Stretching;
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