• Korean Journal of Applied Biomechanics
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• v.33 no.4
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• pp.137-146
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• 2023

Objective: The horizontal bar of gymnastics is fundamentally based on rotational movements. This study aimed to determine the effect of kinematics variables and sequence during horizontal bar performance (Kovacs, Tkatchev Stretched & Kolman) in gymnastic. Method: Four gymnastics athletes of the national team were participated in this study. All subjects were asked to perform the three types of horizontal bar skill. Simi marker-less cameras were used to collect the raw data (120 Hz). Kinematic variables (total time, interval, center of mass, height, angular velocity etc.) and sequence variables were calculated to examine the differences. Results: As a result, horizontal bar performance in gymnastic has special sequence that making the peak angular velocity from distal joint to proximal joint (knee-hip-shoulder). It is rare sequence that typical sport does not have. Conclusion: In field, gymnastic coaches and players should know the result that there is special sequence in horizontal bar performance. It could be very useful to teach and enhance their performance.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.250-260
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• 2021

The purpose of this study is to investigate muscle function and symmetry index during whole body vibration exercise using lower extremity training posture for throwing athletes. For throwing athletes in their 20s(6 males, 4 females, age: 24.60±0.92years, height: 177.90±7.40cm, weight: 92.90±22.97kg), lower extremity training postures with squat, carphrase, and lunge movements. Whole body vibration exercise training was performed using. Tensiomyography(TMG) variables Time Delay(Td), Time Contraction(Tc), Time Sustain(Ts) Time Relaxation(Tr), and Displacement Maximumal(Dm) in the lower extremity joint muscles(biceps femoris(BF), gastrocnemius lateral(GL), gastrocnemius medial(GM), rectus femoris(RF), tibialis anterior(TA), lateral vastus(LV), medial latissimus(ML)), were measured to compare and analyze muscle activity, muscle fatigue, and left-right symmetry. The results of the study are left RF, VL, right VM (p<.05) in Td, VM (p<.05) in Tc, GM in Ts (p<.05), left RF in Tr, and right TA (p<. 05) showed a change. Therefore, it has been proven that various whole-body vibration training is an effective exercise with changes in muscle contraction, and stability of the core is secured by symmetry of the left and right muscles. For this reason, the whole body vibration exercise will have a positive effect on rehabilitation training, and it is believed that it will be able to improve performance.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.519-526
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• 2016

This study aims to verify the relationship between achievement goal orientation and life satisfaction. It consists of 450 athletes from high school, university, and professional teams as an object. After examining reliability and validity on questionnaires, the data, based on gender, was evaluated by analysis of variance, correlation analysis, and multiple regression analysis. The result says that male athletes have higher scores in Mastery approach and Performance approach - two of the four achievement motivation factors - which means a meaningful difference between gender. Life satisfaction also shows that male players have more satisfaction and indicates a big difference between gender. Finally, according to the multiple regression analysis on the Athlete's achievement goal orientation and life satisfaction, Mastery approach affects statically but Mastery avoidance does negatively on athlete's life satisfaction. The gender-based relationship between Athlete's achievement goal orientation and life satisfaction reveals that mastery approach gives positive effects on life satisfaction for both genders, but mastery avoidance influences negatively on male and female life satisfaction.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.495-502
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• 2015

The purpose of this study was to investigating the effect of taping knee by testing the difference on kinetic variables of lower extremity when speed skating athletes jump on one leg. The results were as follows. The height of jumping after taping was higher, but the vertical height was not different according to taping. On take-off(TO), the horizontal and anterior-posterior maximum impulse force were decreased while the vertical maximum impact force was increased after taping. On landing(LD), the anterior-posterior maximum impulse force was decreased but the horizontal and vertical maximum impulse force were increased. TO, the impulse showed low after taping and the impulse dropped largely LD. The knee's moment of extension, eversion were reduced after tapping TO. LD, the flection moment of knee was decreased, but the inversion moment was increased after tapping. This study implies that the knee tapping helps injury prevention and performance enhancement, sports medicine convergence are needed.

• Korean Journal of Applied Biomechanics
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• v.21 no.5
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• pp.503-510
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• 2011

The purpose of this study was to find the biomechanical research project result carried out at 2011 IAAF World championship in Daegu. This project was approved by the International Amateur Athletic Federation(IAAF) and financially supported by the Ministry of Culture, Sports and Tourism(MCST) and, Korea Association of Athletics Federations(KAAF). The total number of the project members was 20, including the members of the Scientific Committee, the Korean Society of Sport Biomechanics(KSSB) and graduate students as assistants. The objective of this project has been to analyze the performance in the track events(100 m, 110 mH) and field events(Long Jump, High Jump, Triple Jump, Pole Vault, Javelin Throw and Shot Put). This project was focused on the biomechanical research only. This kind of analysis has been carried out at major competitions for more than a decade, as it provides coaches and athletes with very useful information as an aid to training programmes and competition preparation. The biomechanical analysis of the top athletes in the world in each specialty serves as a reference for assessing technique and rationalizing the results achieved. The results will be disseminated world-wide and coaches will be in a better position to design training strategies in line with current world trends.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.6-11
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• 2013

Recently sports science is various attempts to improve the athletes' performances. Above all they collect a results for the data and analyze the movement of the players after the game. Based on this, they are utilized to complement the vulnerability and how to improve. However, this way is not able to understand the movement a player and the flow of the game in real time. Because they are analyzed to match results based on the data. Therefore it is possible to managed for performance enhancement used to IT technology during the game in real-time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.189-198
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• 2021

This paper introduces the ball tracking system using image processing. The recent growth of the amateur futsal market has also raised requests for an analysis of amateur players' performance. Sports game analysis services for feedback and growth to athletes or teams are provided in various ways in various sports fields. However, the cost and spatial constraints of sports analysis services make it difficult for providing analysis services to amateur athletes. In this paper, we study and develop a ball tracking algorithm for analyzing futsal game based on the match filming service previously provided in the amateur futsal field. This allows the analysis of the match based on existing services.

• Journal of Life Science
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• v.22 no.3
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• pp.398-406
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• 2012

This study aimed to examine whether the polygenic profile of ACE ID and ACTN3 R577X polymorphisms is associated with muscle power performance in Korean athletes. For this study, 106 top-class power athletes (top-class group), 158 elite power athletes (elite-class group), and 676 healthy adults (control) aged 18-39 yrs were recruited and their genotypes were analyzed. The top-class group showed higher frequencies of the II genotype and I allele in ACE, as well as higher frequencies of the RR genotype and R allele in ACTN3 (top-class vs. control: 41.4% vs. 32.1% for II genotype, 67.1% vs. 57.7% for I allele, p<0.05; 42.3% vs. 29.0% for RR genotype, 65.3% vs. 54.8% for I allele, p<0.05). In the polygenic profile, the top-class group had significantly higher frequencies of combined-II/ID+RR/RX genotype than the control group (top-class vs. control: 82.9% vs. 66.7% for II/ID+RR/RX, p<0.05), and there was even a sharp increase in total genotype score (TGS) in this group compared to the elite-class and control groups ($66{\pm}0.9$ vs. $58{\pm}1.9$ vs. $56{\pm}2.3$, p<0.05). The combined-II/ID+RR/RX genotype showed the possibility of succussion in the top-class muscle power performance with an odds ratio of 2.3 (CI:1.4-4.1, p<0.05). These results suggested that ACE and ACTN3 need to interact with each other to affect muscle-power performance in an additive form. Furthermore, the polygenic profile of ACE and ACTN3 can predict muscle performance with high success in a homogeneous dominant combined genotype (II/ID+RR/RX). A further study could identify and combine other genes into ACE and ACTN3 for muscle strength.

• Journal of Korean Orthopaedic Sports Medicine
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• v.10 no.2
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• pp.86-93
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• 2011

Purpose: The purpose of this study was to analyze the characteristics of the injuries of the national elite Taekwondo players with the best performance in the international championship competition. Materials and Methods: Fifty-two athletes who got the injury in the 2011 Gyeongju World Taekwondo Championship competition were included in this sturdy. 950 members of national team of 146 countries participated in this game, 1,063 matches were performed. We analyzed the characteristics of the injuries such as injury rate by gender, age, weight class, injured region and injury type. Results: Fifty-two athletes of 950 athletes in 1,063 matches got injured and injury rate was 5.47 per 100 participants and 24.47/1,000 athlete-exposures. Injury rate of female athletes was higher than mail, but there was no significant statistical difference (p=0.512). Injury rate of over 30 years old was 17.39 per 100 participants, and injury rate of over 87 kg in male weight class and 68 to 73kg in female weight class were highest than other groups, but there was no significant statistical difference (p=0.838). Overall injury rate of the lower extremity was 13.17/1,000 A-E, higher than upper extremity or head and neck or trunk, but injury rate of the hand was 5.17/1,000 A-E, highest as a specific injured region, followed by the knee, 4.70/1,000 A-E (p=0.714). Injury rate of the sprain was 10.81/1,000 A-E, highest as an injury type, the second most common injury type was the fracture, 5.40/1,000 A-E in men, and was the contusion, 9.63/1,000 A-E in women (p=0.033). As one of the most serious injury, 4 of 8 fractures were occurred in hand. Conclusion: Overall injury rate of the elite Taekwondo players in 2011 Gyeongju World Taekwondo Championship was 5.47 per 100 participants and 24.46 per 1,000 athlete exposures. Although the most common type of injury was the sprain of the knee and ankle, the fractures were more commonly occurred in hand.

• Korean Journal of Exercise Nutrition
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• v.25 no.1
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• pp.7-15
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• 2021

[Purpose] Sodium bicarbonate shows ergogenic potential in physical exercise and sports activities, although there is no strong evidence which performance markers show the greatest benefit from this supplement. This study evaluated the effects of sodium bicarbonate supplementation on time trial performance and time to exhaustion in athletes and sports practitioners. [Methods] A systematic review was conducted using three databases, including 17 clinical trials. Among these clinical trials, 11 were considered eligible for the meta-analysis according to the criteria for the assessment of methodological quality using the PEDro Scale. Time to exhaustion was assessed in six studies, while time trial performance was evaluated in five studies. [Results] A significant beneficial effect of supplementation on time to exhaustion was found in a random effects model (1.48; 95% confidence interval [CI], 0.49 to 2.48). There was no significant effect of supplementation on time trial performance in a fixed effects model (slope = -0.75; 95% CI, -2.04 to 0.55) relative to a placebo group. [Conclusion] Sodium bicarbonate has the potential to improve sports performance in general, especially in terms of time to exhaustion.