• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.193-204
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• 2002

The purpose of this study was to investigate the effect of martial art type and target height on the ground reaction force factors during Dollyuchagi motion. Data were collected using force plate. Five Taekwondo players and five Hapkido players were tested during Dollyuchagi motion to three different target heights(0.8, 1.2, 1.6 m). After analysis of kinetics using force plate data, maximum vertical ground reaction force was 1.62~2.44 BW, and impulse was $0.66\sim1.01 BW{\cdot}s$. Even though there was no difference for maximum ground reaction forces and impulse between Hapkido and Taekwondo, as target height was higher, impulse increased. Anterior-posterior and vertical ground reaction forces at kicking foot take-off were greater with target height, although there was no difference for medio-lateral force with target height. At impact there was significant difference for anterior-posterior ground reaction force between Hapkido and Taekwondo players. Taekwondo players' force (range, -0.23~-0.26 BW) was greater than Hapkido players's force (range, -0.08~-0.14 BW).

• Korean Journal of Applied Biomechanics
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• v.30 no.1
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• pp.63-72
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• 2020

Objective: The purpose of this study was to investigate meta-analysis on the effects of exercise therapy and physiotherapy on pain in korean patients with chronic low back pain. Method: Meta-analysis was performed on the type and method of treatment. A total of 23 experimental studies were coding into 31 individual studies, into types, methods, visual analogue scale (VAS), each pre/post value of the effect size was calculated by meta-analysis. Results: Sling exercise, stretching, thermal therapy, kinesio-taping, lumbar stabilization exercise, electrotherapy is large effect size (ES ≥ .08). In addition, big effects occurred in order of treatment period is more than 9 weeks, three times a week. Conclusion: Our results indicated that persistent treatment of chronic back pain is the most effective method of self-sufficiency rather than temporary relief.

• The Research Journal of the Costume Culture
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• v.9 no.2
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• pp.295-307
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• 2001

This study was investigated to a effect of sociocultural environment on the vicissitudes of headgear in Europe on 19th Century. Form of headgear was increasingly more functional and simple. It was needed various items with various usage. Since Industrial Revolution the french Revolution. A diffusion of sport and increase of leisure time gave rise to entrance of mass headgear with reasonability and simplicity. But female headgear was more decorative than males. Until late 19th century when female has participated in social performance, female headgear was not functional and simple form. More often female took male headgear(fedora, straw boater, cap, tc.) than bonnet when female role-awareness was changed and sport is diffused.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.1-12
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• 2003

This study was performed to provide normative isokinetic strength of knee muscles of middle school non-athletic and athletic populations for rehabilitation and pre-season screening for injury prevention. Seven non-athletic subjects and 8 hockey players participated in this investigation. Each subject was tested at speeds of $60^{\circ}/sec$, $180^{\circ}/sec$, and $300^{\circ}/sec$. The free weight of lower leg was measured at speed of $60^{\circ}/sec$ to take gravity effect Into consideration when peak torque of knee muscles occurred. The results showed that the relative peak torque production of knee flexors did not change but the relative peak torque of knee extensors decreased significantly. Mamstring/quadriceps ratios increased mainly due to significant decreases in knee extensors torque production. No significant differences were found between groups. The hamstring/quadriceps ratios for both groups were significantly lower when the gravity effect was not eliminated.

• Journal of Technologic Dentistry
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• v.44 no.3
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• pp.89-96
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• 2022

Purpose: The purpose of this study was to investigate the types of mouthguards athletes who play contact sports use as well as their perceived discomfort of wearing them in order to analyze the relationship with wearing frequency so as acquire basic data for the development of more user-friendly mouthguards. Methods: The participants, who completed a self-report questionnaire, included 70 contact sports athletes, including high school contact (rugby and boxing) sport department affiliated athletes located in the city of Daejeon. Results: Breathing (p<0.01), fitting (p<0.05), ease of wearing (p<0.01), occlusion (p<0.05), and fatigue in muscles (p<0.05) were positively correlated with wearing frequency. Furthermore, the recognition of the mouthguards was not significantly correlated with wearing frequency. Conclusion: To prevent oral and maxillofacial trauma, multi-directional studies are imperative to develop mouthguards, which are comfortable and cost-efficient.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1556-1566
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• 2020

The purpose of this study was to investigate the effect of Nurida-Ball exercise on isokinetic muscle function, spinal alignment, and dynamic balance capacity in middle-aged men. All middle-aged men(n=16) were divided into 2 groups: Ball exercise(BE, n=8) and control(CON, n=8) group. BE group performed the Nurida-Ball exercise(30 min/day, 3 days/week, 8 weeks) and isokinetic knee and trunk muscle function, spinal alignment, and dynamic balance capacity were measured. All of the measured variables calculated the mean and standard deviation and verified normality using the Shapiro-Wilk test. The independent t-test method and the Paired t-test method were then analyzed to identify differences between groups. This study found that isokinetic knee and trunk muscle function was significantly strengthened in the BE compared with CON group by increasing peak torque(PT) of right and left knee extension(60°/sec, p<0.01, respectively), average power(AP) of right and left knee extension(60°/sec, p<0.05, p<0.01, respectively), and PT of right knee flexion(180°/sec, p<0.05) and AP of right knee extension(180°/sec, p<0.05). In the change of isokinetic trunk muscle function, only PT of trunk extension(180°/sec) was increased in the BE compared with the CON group(p<0.05). In addition, Nurida-ball exercise can improve the spinal alignment by reducing the trunk inclination(p<0.05) in the BE compared with the CON group. Finally, dynamic balance capacity was also enhanced in the BE compared with the CON group by decreasing the score of overall balance index(OBI, p<0.01) and Antero-posterior balance index(p<0.05) in the Stage-6, and OBI(p<0.05) in the Stage-1. This result demonstrated that Nurida-ball exercise may improve spinal alignment, dynamic balance capacity, and isokinetic muscle function, which might be an effective way for the improvement of health-related fitness in middle-aged men.

• Journal of the Korean Data and Information Science Society
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• v.23 no.2
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• pp.317-331
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• 2012

The purpose of this study was to verify the relationship among servant leadership, empowerment and sports satisfaction of badminton coaches by self-leadership. Among national badminton players, total 343 copies of data were collected and used at the study by using of random sampling. The normal distribution on data and the validity and reliability for each factors were proven to confirm through descriptive statistics, exploratory & confirmatory factor analysis and reliability analysis with SPSS 18.0 and AMOS 18.0 program. The relationship among each factors by the purpose of study were analyzed by correlation analysis and structural model analysis. The results were as follows. First, the servant leadership of badminton coaches had positive effect on empowerment. Second, the servant leadership of badminton coaches had positive effect on self-leadership. Third, the servant leadership of badminton coaches had positive effect on sports satisfaction. Fourth, empowerment had positive effect on sports satisfaction. Fifth, self-leadership had positive effect on sports satisfaction. Sixth, for the relationship between servant leadership and sports satisfaction, empowerment and self-leadership had indirect effects.

• Korean Journal of Exercise Nutrition
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• v.25 no.3
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• pp.1-7
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• 2021

[Purpose] We aimed to identify the effects of marine oligomeric polyphenol (MOP) intake in elderly individuals with sarcopenia. [Methods] Older adults (aged 65 years or older) were recruited based on the diagnostic criterion for sarcopenia and were randomly assigned to the MOP intake group (n=10) or the placebo (PBO) intake group (n=10). To determine the effect of MOP intake received for four weeks, the pre- and post-intake body composition (weight, skeletal muscle mass, and bone density) and senior fitness tests were assessed. [Results] Our results showed there were significant differences in the skeletal muscle mass (p=0.039), bone density (p=0.020), fat-free mass index (p=0.026), and 2.4 m up and go test (p=0.001) between pretest and post-test. There was a significant difference between the pre-test and post-test and an interaction effect for the one-leg stand test (p=0.010 and p=0.049, respectively). However, there were no significant differences in body fat percentage, calf circumference, grip strength, or the chair rise test. [Conclusion] Some variables exhibited significant differences in the pre- and post-assessments, and there was an interaction effect for the one-leg stand. However, this was insufficient to prove the effectiveness of MOP intake in improving sarcopenia. Therefore, additional studies are essential to examine the effects of MOP intake and exercise intervention on the body composition and fitness of patients over a longer period.

• Korean Journal of Applied Biomechanics
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• v.33 no.3
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• pp.101-109
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• 2023

Objective: The aim of this study is to verify the differences in muscle characteristics of elite level swimmers before and after a 2-hour practice session. Method: The study was conducted on 15 elite swimmers. Preliminary measurements for each muscle (Anterior Deltoid, Triceps Brachii, Biceps Brachii, Flexor Carpi Ulnaris) were taken using the MyotonPRO device before training. After approximately 2 hours of training, the same muscle areas were measured again. The collected data was analyzed through descriptive statistics and two-way 2×2 RG·RM ANOVA, and all statistical significance levels were set at α=.05. Results: After analyzing the characteristics of the Flexor Carpi Ulnaris (FCU) before and after training in both proficiency level swimmers (excellent, non-excellent), it was found that the interaction effect of group X repetition in muscle tension (F), muscle stiffness (S), and body recovery time (R) was statistically significant. Secondly, in the analysis of the Biceps Brachii (BB), the main effect of repetition in muscle tension (F), muscle stiffness (S), and body recovery time (R) was statistically significant. Furthermore, the interaction effect of group X repetition in muscle stiffness (S) and body recovery time (R) was statistically significant. Conclusion: The efficient use of FCU and BB suggests that it is an important factor distinguishing the performance of excellent and non-excellent swimmers in swimming. Therefore, if we develop and apply measures to efficiently utilize FCU and BB during training, it can help improve the performance of the athletes.

• Journal of Life Science
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• v.19 no.5
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• pp.644-651
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• 2009

The objective of this study was to identify EXE (1 hr a day at 21 m/min for 5 day/wk, at 0 % grade for 6 wk) on myocardium glucose metabolic phenotypic proteins (AMPK-PGC-1${\alpha}$-GLUT-4) and HSP-60 protein expression after ischemia/reperfusion injury (IRI) in STZ-induced rats. EXE was performed using STZ-induced diabetic rats on a rodent treadmill (28 m/min, 1 hr/day, 5 day/wk for 6 wk). The results of this study suggest that i) serum insulin level was not changed among groups (p>l0.05). ii) the LVDP level increased significantly in the STZ-EXE-IRI group compared to the STZ-IRI group at 60 min (p<0.01), 70 min (p<0.05) and 80 min (p<0.05) after reperfusion, respectively, and iii) AMPK phosphorylation (p<0.01), PGC-1${\alpha}$ protein (p<0.001), GLUT-4 protein (p<0.001) and HSP-60 protein expressions (p<0.05) increased significantly in the STZ-EXE-IRI group compared to the STZ-IRI group. In conclusion, the findings of the present study reveal that EXE may provide therapeutic value to insulin dependent diabetic patients with peripheral insulin resistance and myocardium injury by improving glucose metabolic proteins (AMPK-PGC-1${\alpha}$-GLUT-4) and heat shock protein-60 (HSP-60), along with increasing LVDP levels and decreasing glucose levels. Therefore, EXE protects the STZ-induced diabetic myocardium injury against ischemia/ reperfusion injury.