• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.27-33
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• 2014

In volleyball, the most common injuries are anterior cruciate ligament (ACL) tears. For this reason, volleyball players frequently use knee brace as prophylactic and rehabilitation measures. The purpose of the study was to investigate the effects of knee brace on anterior cruciate ligament injuries risk factors during spike take off in female volleyball players. Fifteen female volleyball players were recruited and performed randomly spike take off with and without knee brace. Kinematics and ground reaction data were collected to estimate the anterior cruciate ligament injuries risk factors. The ACL risk factors are knee maximum flexion angle, thigh maximum adduction angle, thigh maximum internal rotation angle, shank maximum abduction angle, shank maximum external rotation angle, knee maximum extension moment and knee maximum abduction moment. Data were analyzed with paired samples t-test with Bonfferoni collection. Female volleyball players with knee brace had no significant results in knee maximum flexion angle, thigh maximum adduction angle, thigh maximum internal rotation angle, shank maximum abduction angle and shank maximum external rotation angle compare to without knee brace. Female volleyball players, however, with knee brace showed more reduced knee maximum extension moment and knee maximal abduction moment than without knee brace. In conclusion, Female volleyball players with knee brace reduced anterior cruciate ligament stress.

• Korean Journal of Applied Biomechanics
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• v.26 no.2
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• pp.205-211
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• 2016

Purpose: The aim of this study was to analyze biomechanical factors and PMT (premotor time) of body muscles between elite college and amateur baseball players during the baseball batting motion. Method: Kinematic and electromyographic data were obtained for 10 elite college baseball players and 10 amateur baseball players who participated in this study. All motion capture data were collected at 200 Hz using 8 VICON cameras and the PMT of muscles was recorded using a Delsys Trigno wireless system. The peak mean bat speed and the peak mean angular velocities of trunk, pelvis, and bat with PMT of 16 body muscles were computed. These kinematic and PMT data of both groups were compared by independent t-tests (p < .05). Results: The pelvis, trunk, and bat showed a sequence of angular velocity value during baseball batting. The PMTs of right tibialis anterior, left gastrocnemius, external oblique, and erector spinae were significantly different between the two groups. Conclusion: The PMT of body muscles was related to the shifting of body and rotation of the pelvis and the trunk segment, and this action can be considered the coordinated muscle activity of the lower and upper body.

• Journal of Sport and Applied Science
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• v.8 no.2
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• pp.13-18
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• 2024

Purpose: The purpose of this study is to determine the effects of a 6-week weight training and complex training program on the Y-balance test (YBT) in high school soccer players. Research design, data, and methodology: This study included 26 high school soccer players from City S. Subjects were divided into a weight training group (WTG: n=13) and a complex training group (CTG: n=13) based on their willingness to participate without medical problems. The YBT measured anterior (AT), posteromedial (PM), posterolateral (PL), and composite scores (CS), and was measured twice: before the start and after the end of training. The data were analyzed using the SPSS 25.0 statistical program to compare pre- and post-training using paired-t tests, between training groups using independent-t tests, and left-right comparisons using independent-t tests. Results: Training resulted in a significant pre- to post-training change in PL in the left foot WTG group (p<.05), with no significant change in the other measures. There were no significant differences between training groups and between left and right sides. Conclusion: To improve YBT in high school soccer players, a program to improve ankle and hip mobility and strength should be added along with improving large muscle strength through weights and comflex training.

• 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.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.391-398
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• 2019

This study aimed to investigate the factors that influence the attitude toward doping and to provide useful information for developing a doping prevention program suitable for Korean athletic players. One hundred and seventy-two players who enrolled in Korea Association of Athletics Federations were participated in this study and they filled in the questionnaire about demographic factors, information on doping, perfectionism, and perceived motivational climate. Collected data were analyzed by using stepwise multiple linear regression for exploring the main factor that affect the attitude toward doping depending on field and track events. All adult players have more permissive attitude toward doping than adolescents. In track event, while players who are sensitive to coach's criticism have more permissive attitude toward doping, players who focused on personal standards have more repressive attitude toward it. These results would be useful to develop anti-doping strategy for Korean field and track players.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.59-66
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• 2022

This study was conducted to find out whether excellent and non-excellent players could be distinguished by the achievement goal orientation(task-orientation, ego-orientation) test and the self-management(physical, interpersonal, training, mental management) test targeting youth soccer players. The subject of this study were 299 players(144 middle school students, 155 high school students) including 131 representative players by age and 168 general players who registered with the Korea Football Association. The questionnaires for data collection include the Task & Ego Orientation in Sport Questionnaire(TEOSQ) developed by Duda and Nicholls(1989) and the athlete self-management questionnaire(ASMQ) developed by Heo Jeong-hoon(2003) was used. For data analysis, frequency analysis, factor analysis, reliability analysis, and discriminant analysis were performed using SPSS 23 version. As a result of analyzing the data, task orientation and ego orientation, which are sub-factors of achievement goal orientation, were both confirmed as tests that did not discriminate between excellent and non-excellent players. On the other hand, the self-management test was confirmed as a test that can discriminate between excellent and non-excellent players in body management, training management, and mental management excluding interpersonal management among the sub-factors of self-managemnet. In particular, among self-management, mental management was identified as the most important factor in discriminating between excellent and non-excellent athletes.

• Korean Journal of Applied Biomechanics
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• v.31 no.4
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• pp.234-240
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• 2021

Objective: The purpose of this study is to analyze the distance, number, duration, velocity of sprints generated during women's hockey competition by position to identify sprint patterns. Method: The data was collected in 17 matches between 2016 and 2018, 49 elite women's hockey players were tested using SPI-HPU to identify differences by position using SPSS 25.0. A total of 376 Sprint information was utilized. Results: First, women's hockey players all showed significant differences in the number of sprints, duration, distance, and max velocity depending on their positions. Second, there was a significant difference in the number of sprints in the difference between quarters. And the factors of duration, distance, and max velocity showed differences between positions. Third, according to the results, there were differences in the number of times, duration, distance, and max velocity in the difference between positions. Conclusion: These results can be confirmed the sprint patterns of depends on position during the women's hockey game and can be used as information for the development of physical and tactical training programs.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.591-604
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• 2017

The purpose of this study was to develop and evaluate the program for convericient reconfiguration in an attempt to change maladjustmental way of thinking among female junior tennis players. For verification of the program, a qualitative analysis and quantitative analysis were carried out. Through the REBT program for convericient reconfiguration, maladjustmental way of thinking among junior tennis players was drawed and interviews with them were subsequently performed. As a result, REBT counseling technique was applied to understand personal psychological problems and to transform maladjustmental and unreasonable way of thinking into rational belief, confirming positivity toward their situation. After all, their athletic performance as well as holistic development was found to be improved. In quantitative analysis, maladaptive thinking scale sports psychology questionnaire and survey for Korean sports performance strategy were both increased post treatment, suggesting that their psychological status became positive as a result of application of psychological prevention. The results of this study showed that athletic performance would be enhanced and growth and development in personality and self-realization would be expected if various psychological problems in adolescent players were progressed in detailed.

• 대한정형외과스포츠의학회:학술대회논문집
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• 2004.09a
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• pp.63-63
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• 2004

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.31-38
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• 2008

The purpose of this study was to investigate the effects of anterior cruciate ligament (ACL) injury prevention program on the ground reaction force during the rebound in female highschool basketball players. Sixteen highschool female basketball players (ages 16 to 18 years) were participated in this study. Eight of these players participated in a 8-week ACL injury prevention program. Before and After ACL injury prevention program, initial peak value(%BW), maximum peak value(%BW), impulse(%BW sec), and loading rate(N/sec) were measured in the players. The experiment group after ACL injury prevention program showed significant decreased initial peak value, impulse, and loading rate.