• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.119-127
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• 2023

Objective: This study aimed to compare the activity of the trunk and leg muscles while performing fente (in fencing) wearing weighted and waterbag vests. Method: The electromyography test was used to measure and analyze the activation of the trunk and leg muscles. Eight active fencers from B University (age: 19.5 ± 0.66 years, height: 179.75 ± 5.93 cm, weight: 72 ± 6.32 kg) were selected for this study. Results: According to the EMG analysis results of the 4 muscles measured in this study, left-right differences were observed for rectus abdominis and external oblique abdominis, but left-right differences between the groups were not significant. The gluteus medius muscle was not significantly different from the adductor muscle, but there were significant differences between the groups. Conclusion: The electromyographic analysis of the four muscles measured in this study revealed no significant difference between the left and right recti abdominis and external obliques depending on the vests. However, significant differences were observed between the left and right gluteus medius and adductor longus. Our results can be interpreted as the effects of the inherent movements involved in the fente. Furthermore, our results indicate that the weight transfer while wearing a waterbag vest, which provides an unstable environment, increased the activity of leg muscles.

• IMMUNE NETWORK
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• v.16 no.2
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• pp.109-115
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• 2016

To find the relation between exercise and cytokines, we examined the effect of the training intensity on the levels of cytokines, including interferon-gamma (IFN-γ), interlukine-4 (IL-4) and interlukine-4/interferon-gamma ratio (IL-4/IFN-γ ratio) in female Futsal players. Twelve well-trained female college Futsal players aged 19~22 participated in this study. The athletes completed 30-min of running at 60~65% maximal heart rate [moderate-intensity exercise], and 30-min of running at 75~80% maximal heart rate [high-intensity exercise]. peripheral blood samples were collected 24 h before and 24 h and 48 h after each of the exercise bouts. finding showed that The 30-min bout of moderate-intensity exercise induced a significant increase in IFN-γ (p=0.01) and significant decreases in IL-4 (p=0.001) and IL-4/IFN-γ ratio (p=0.003). And also, 30-min of running at 75~80% maximal heart rate induced increase in IFN-γ (p=0.07) and decreased in IL-4 (p=0.01) and IL-4/IFN-γ ratio (p=0.06) that these changes not significantly. In summary, exercise intensity can effect on the magnitude of changes in cytokines. It seems that moderate intensity exercise enhances cytokine pattern in female college Futsal players.

• Korea Science and Art Forum
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• v.28
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• pp.23-32
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• 2017

The purpose of this study is to contribute to the activation of sports for the disabled people in Korea through the localization of the road racing handcycles. Recently, there are no handcycles produced in Korea, and all the players are using products made in foreign countries. In the case of foreign products, it is made to fit the body shape of foreign athletes. Therefore, when domestic players are using them, they put additional parts to foreign products in order to fit their body shape. This not only adds to the cost burden, but also causes a decrease in the performance of the athletes. In order to overcome these problems, we developed the road racing handcycle in consideration of the body shape of the Koreans and conducted a comparative usability evaluation with the foreign products to evaluate the performance of the developed prototype. Therefore, we analyzed the quantitative and qualitative evaluation results of the prototype produced in the previous study, and developed the Korean road racing handcycle that can improve the competitiveness while considering the shape of domestic players. Based on the problems derived from the first prototype, this study additionally constructed a crank, an air intake part and a discharge part, and a rear anti-shake prevention device. In order to evaluate the usability, we conducted a comparative usability assessment with the foreign products used by the current standing handcycle athletes. The results were measured in the area of effectiveness, efficiency, and satisfaction, and the prototype developed through the research on efficiency and satisfaction excluding effectiveness was evaluated to be higher than those of foreign products. This study will contribute to the improvement of international competitiveness due to import substitution effects of foreign products and exports by lowering the handcycle cost of importing foreign handcycle.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.886-904
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• 2018

The 3D(dimension) vritual reality(VR) has already been used in various sports fields, especially in the training of elite athletes. It is mainly used to maximize the effectiveness of image training, and the use of VR-based image training has received special attention as evidence-based pratices for its feasibility, practicality, and appropriateness. However, in recent years, the use of VR is no longer used only for the training of elite athletes, but is widely used in social sports. This is because, the advantage of exercise in VR is that it is highly stable and has fewer restrictions from the external environment. Considering these advantages, it can be used for the elderly physical activity. This study identifies and reviews studies applying VR-based image training. Several recommendations for the future study on VR-based image training for the older such as interdisciplinary approach to VR-based image training, support needs regarding characteristics of the older, and generalization and maintenance of acquired technology were discussed.

• Journal of Life Science
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• v.27 no.5
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• pp.591-599
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• 2017

It is well established that endurance performance is negatively affected by environmental heat stress. Numerous scientific investigations have attempted to improve performance in the heat with pre-cooling and per-cooling for endurance athletes. Some cooling strategies are more logistically challenging than others, and thus are often impractical for use in training or competition. The purpose of this study was to review the literature on the use of cooling interventions in the improvement of performance and recovery from exercise-induced heat stress. We undertook an examination that focused on the effects of pre-cooling and per-cooling on the improvement in endurance performance and the effects of post-exercise cooling on recovery. The benefits for pre-cooling and per-cooling strategies undertaken in the laboratory setting could be employed by athletes who compete in hot environmental conditions to improve performance. Most laboratory studies have shown improvements in endurance performance following pre-cooling and per-cooling, and in recovery following post-cooling. Cooling strategies such as cooling vest, neck cooling collar, menthol and ice slurry are practically relevant to sports field. Cooling interventions that can be applied frequently to reduce thermal strain prior to, during and directly after training appear to be the best effective strategy to improve performance and recovery. Future research is warranted to investigate the effectiveness of practical pre-cooling and per-cooling strategies in competition or field settings.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.325-339
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• 2021

The purpose of the study is to examine sports-related cognitive functions through a systematic review and to suggest effective instruments to measure the cognitive functions. The present study was conducted based on the systematic review and meta-analysis protocol-the PRISMA. Of 429 articles searched through keywords from 2008 to 2020, 45 articles that met the selection criteria were analyzed. It was revealed that athletes had better cognitive functions than non-athletes, that the higher the sports expertise was, the higher the cognitive functions, and that there were differences in cognitive functions according to the sport types. The primary cognitive functions related to sports performance summarized as executive functions (inhibition ability, cognitive flexibility), information processing speed, spatial ability, and attention. As tasks for measuring each cognitive function, a stop signal task for inhibition ability, a design flexibility task for cognitive flexibility, a simple and choice reaction time test for information processing, a mental rotation task for spatial ability, and an attention network test for attention are appropriate.

• Korean Journal of Applied Biomechanics
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• v.33 no.3
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• pp.110-117
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• 2023

Objective: The purpose of this study was to find out kinematic and kinetic differences the lower extremity joint according to the landing type during vertical jump movement after jump landing, and to present an efficient landing method to reduce the incidence of injury in youth players. Method: Total of 24 Youth players under Korean Sport and Olympic Committee, who used either heel contact landing (HCG) or toe contact landing (TCG) participated in this study (HCG (12): CG height: 168.7 ± 9.7 cm, weight: 60.9 ± 11.6 kg, age: 14.1 ± 0.9 yrs., career: 4.3 ± 2.9 yrs., TCG height: 174.8 ± 4.9 cm, weight: 66.9 ± 9.9 kg, age 13.9 ± 0.8 yrs., career: 4.7 ± 2.0 yrs.). Participants were asked to perform jump landing consecutively followed by vertical jump. A 3-dimensional motion analysis with 19 infrared cameras and 2 force plates was performed in this study. To find out the significance between two landing styles independent t-test was performed and significance level was set at .05. Results: HCG showed a significantly higher dorsi flexion, extension and flexion angle at ankle, knee and hip joints, respectively compared with those of TCG (p<.05). Also, HCG revealed reduced RoM at ankle joint while it showed increased RoM at knee joint compared to TCG (p<.05). In addition, HGC showed greater peak force, a loading rate, and impulse than those of TCG (p<.05). Finally, greater planta flexion moment was revealed in TCG compared to HCG at ankle joint. For the knee joint HCG showed extension and flexion moment in E1 and E2, respectively, while TCG showed opposite results. Conclusion: Compared to toe contact landing, the heel contact landing is not expected to have an advantage in terms of absorbing and dispersing the impact of contact with the ground to the joint. If these movements continuously used, performance may deteriorate, including injuries, so it is believed that education on safe landing methods is needed for young athletes whose musculoskeletal growth is not fully mature.

• Journal of Korean Foot and Ankle Society
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• v.13 no.2
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• pp.193-196
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• 2009

The first metatarsophalangeal joint injury is common in professional soldiers and athletes. But this was rarely reported. A professional soldier has varus instability in the first metatarsophalangeal joint due to hyperextension. In the MR Imaging, weavy appearance in lateral collateral ligament and high signal change in plantar plate was shown. So he has surgical treatment using reconstructive procedure. At first, $4^{th}$ extensor digitorum longus tendon was splitted longitudinally and harvested, second triangular shape reconstruction on lateral joint line was done using harvested tendon. One year later, fifteen degrees was limited compared with intact side. Reconstruction using $4^{th}$ extensor digitorum longus tendon in traumatic dynamic hallux varus was good method.

• The Korean Journal of Pain
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• v.31 no.1
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• pp.54-57
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• 2018

Burner or stinger syndrome is a rare sports injury caused by direct or indirect trauma during high-speed or contact sports mainly in young athletes. It affects peripheral nerves, plexus trunks or spinal nerve roots, causing paralysis, paresthesia and pain. We report the case of a 57-year-old male athlete suffering from burner syndrome related to a lumbar nerve root. He presented with prolonged pain and partial paralysis of the right leg after a skewed landing during the long jump. He was initially misdiagnosed since the first magnet resonance imaging was normal whereas electromyography showed denervation. The insurance company refused to pay damage claims. Partial recovery was achieved by pain medication and physiotherapy. Burner syndrome is an injury of physically active individuals of any age and may appear in the cervical and lumbar area. MRI may be normal due to the lack of complete nerve transection, but electromyography typically shows pathologic results.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.1
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• pp.7-11
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• 2011

Purpose: The purpose of this study is to investigate the differences of dynamic visual acuity to color of optical lens. Methods: we measured dynamic visual acuity using 5 colored lenses (transparent, yellow, blue, green, brown) for 30 university students. Results: Dynamic visual acuity were highest on yellow colored lens and lowest on brown colored lens, for both of naked eyes and contact lens wearers. Conclusions: It can be concluded that optical lens color can influence on dynamic visual acuity. Selection of colour lense can enhance or decrease of dynamic visual acuity. Therefore, a selection of colour lense should be carefully decided especially for athletes who needs a good dynamic visual acuity.