• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.481-488
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• 2009

The purpose of this study was to investigate the hokey scoop motion of elite male hockey players. To accomplish the goal of this study, eight male hockey players participated and were divided into two groups (superior group Vs. inferior group). To find differences between groups, a three-dimensional motion analysis was performed with seven infrared cameras (SF: 200Hz). After analyzed their scoop motion, followings were found. 1) The non-significant(p>.05) increase in anterior CG displacement and velocities were found in superior group compare with inferior group) 2) There were no significance found in anterior-posterior stick velocities between groups. However, significant (p<.05) increase in vertical stick velocities were found in superior group than inferior group indicating the superior group has more skilled in scooping. 3) The significant(p<.05) increase in adductional and internal rotational stick released velocities were found in superior group than inferior group.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.153-163
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• 2006

The purpose of this research was to analyze kinematic variables that appear during the instep shooting motion of female high school soccer players according to the angle of approach to find effective shooting motions. For this experiment, 5 female high school soccer players from the K city were participated in this study as the subject group, and as a through comparison and analysis of the resulting numbers of the variables, we came to the following conclusions. 1) Stride length and stride length/lower extremity length increased as the angle of approach increased. 2) As for C.O.G movement displacement, it was highest at an approach angle of $90^{\circ}$ during Right Foot Contact, at $135^{\circ}$ during Left Foot Contact, at $0^{\circ}$ during Rigth Toe Top, at $45^{\circ}$ during Impact, and at $0^{\circ}$ during Follow through. 3) The time required for each phase was longest at APP and shortest at BSP. The time required increased a little as the angle of approach increased, and the total time required also increased as the angle of approach increased. 4) The angle of the ankle joint was largest at an approach angle of $45^{\circ}$ for all events except Right Foot Contact. 5) The angle of the knee joint was largest at an approach angle of $135^{\circ}$ during Right Foot Contact, at $0^{\circ}$ during Left Foot Contact, at $45^{\circ}$ during Right Toe Top, at $135^{\circ}$ during Impact, and at $90^{\circ}$ during Follow through. 6) The angle of the hip joint was largest at an approach angle of $90^{\circ}$ during Right Foot Contact, at$0^{\circ}$ during Left Foot Contact, at $0^{\circ}$ during Right Toe Top, at $90^{\circ}$ during Impact, and at $0^{\circ}$ during Follow through.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.49-63
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• 2003

For this study, four male university Taekwondo players were randomly chosen, between the weight categories of 60Kg and 80Kg. Their side kicks (yeop chagi), which are part of foot techniques, were kinematically analyzed in terms of the time, angle, and angular velocity factors involved with the kicks through the three-dimensional imaging. The results of the analysis are as fellows. 1. Time factor The first phase(preparation) was 0.48sec on average, accounting for 60% of the entire time spent; the second phase(the minimum angle of the knee joint) was 0.21sec on average, taking up 26% of the whole time spent; and the third phase(hitting) was 0.11sec on average, representing 14% of the entire time spent. 2. Angle factor In the first phase(preparation), rotating their bodies along the long axis, the players bended their hip and knee joints a lot, by moving fast in the vertical and horizontal directions, in the second phase(the minimum angle of the knee joint), the players continued to extend their bodies along the vertical axis, while pronating their lower legs and bending their hip and knee joints a lot to reduce the radius of gyration, and in the third phase(hitting), they extended their knee joints greatly so that the angle movements of their lower bodies shifted to circle movements. 3. Angular velocity factor In the first phase(preparation), the angular velocity of the hip and knee joints increased. while moving horizontally and rotating the body along the long axis; in the second phase(the minimum angle of the knee joint), the angular velocity increased by bending the hip and knee joints fast to reduce the rotation radios; and in the third phase(hitting), the angular velocity was found to have increased, by rotating the body along the long axis to increase the angular velocity and shifting the angular momentum of the pronated knee joint to the circular momentum.

• Korean Journal of Applied Biomechanics
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• v.29 no.3
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• pp.129-135
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• 2019

Objective: The purpose of this study is to present the scientific and quantitative data by finding the common points and differences of the side-kick according to the height change through the difference of the side kick motion performance according to the three target height changes and the function of the lower limbs muscle in side kick motion of Taekwondo Poomsae. Method: For this, total 14 players were selected who were registered in Korea Taekwondo Association and skilled group 7 players who had a medal from national competition and 7 players who did not have Taekwondo experience from department of physics. 4 video cameras to the feature on side kick per target height, and the subjects' support foot was located on the ground reactor and the practice was conducted 3 times: waist, chest, and head as the target height. the basic materials were collected by using Kwon 3D XP program and the T-test was conducted to verify the statistic difference between groups (SPSS 24.0). At this time, the statistics significance level was set as .05 and the following conclusion was obtained. Results: The lower the proficiency and the higher the height, the more the joint coordination between the hip and the knee. Conclusion: Summary of the result shows a common point that the change of target's height makes the lower the proficiency and the higher the height, the more the joint coordination between the hip and the knee. Also, the higher the target's height became, the greater angular momentum of thighs, shanks, foot became in common.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1606-1615
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• 2021

The purpose of this study is to provide basic data for injury prevention and performance improvement by developing a flywheel training program for handball players. The results of analyzing the effects of the 12-week complex flywheel training program on body composition, physical fitness factors, anaerobic power, and isokinetic muscle function are as follows. There was a significant difference between groups in push-ups. Body fat percentage and anaerobic power showed significant differences in the interaction by period. Long jump, slow jump, grip strength, back muscle strength, anaerobic average power, and isokinetic muscle function tests showed significant differences by period in the left and right flexors. Therefore, it is considered that 12-week flywheel training results can be used as the basic data for injury prevention and improvement of performance in handball players.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.123-130
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• 2009

The purpose of this study was to provide the basic information on nutritional condition for improving performance of the national junior rowing team players(male n=17, female n=14). To attain this purpose, their body composition and energy intake situations were investigated during their three-week winter training camp. Measurement of body composition measured by the interval, and two days, and dietary intake in this study to investigate the type and amount of food, the researchers measured directly, and then refer to the record subjects to investigate the dietary intake and the adoption of a Weighing Method. The result is as follows. During training, body composition due to the high intensity training to maintain a properly balanced diet is the consumption of energy, weight and body composition has a positive influence. The male players' average energy intake is 5,951.6 kcal(72.6 kcal/kgBW, 150%), the rate of the three main nutrients, carbohydrate, fat, protein, is 72.6 : 8.7 : 18.7 respectively. For the female, the average energy intake is 3,685.6 kcal(51.8 kcal/kgBW, 121%), and the rate of the three main nutrients is 76.3 : 8.5 : 15.2. Both of male and female were taken sufficient Vitamin, mineral and other nutrient according to %RI(recommended intake). Based on the results of a survey of elite athletes and nutrition management and the systematic introduction and review of the program in conjunction with a professional nutritionist would need, and can also be applied to expand the school to the scene, the reality of the program review and development of qualified need.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.12
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• pp.3839-3847
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• 2009

This study presents a revitalization of the professional leagues through the identification of the problem based on analyzing the domestic professional sports business environment. The development plan for emerging problem is present along with guidelines that are appropriate for local environment and situation for league revitalization. First, the creation of a variety of marketing opportunity and integrated marketing strategy must be accompanied by the development for generating of the professional sports league's revenue. Second, Marketing of a player's potential should be developed. and utilized. Third, the domestic players and foreign players salary cap celery cap placed on the proportion of salary should be lower. Finally, Youth Club, based on the activation of a growing base should be made.

• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.17-24
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• 2012

This study is for providing fundamental data of sport biomechanics in GRF & plantar pressure of stepping foot of skilled & unskilled players' at the soccer instep shooting moments. Wearing Pedar-x of Novel, the study has drawn the following conclusion after measuring and analyzing the impact on the GRF and plantar pressure of stepping foot at the instep shooting moments. First, maximum vertical GRF showed higher in the skilled group than in the unskilled group. The results showed significantly different. This study reached the conclusion that the players in the skilled group performed faster and stronger stepping foot motions that the ones in the unskilled(p<.01). Second, since the plantar pressure of the skilled group appeared significantly higher than that of the unskilled, it has brought us to the conclusion that the skilled group performed faster and stronger stepping foot motions than the unskilled group (p<.05). Third, at the moment of instep kicking, the skilled group's average maximum plantar foot pressure of stepping foot was higher than the unskilled. Though the difference was not statistically significant, it can be concluded that the skilled group performed faster and stronger stepping foot motions than the unskilled group(p>.05). Fourth, for the COP moving route of stepping foot while instep kicking, the skilled people performed accurate and strong shooting motions directly toward the target direction with stable postures, no matter how it's left, right, front or back.

• Korean Journal of Applied Biomechanics
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• v.20 no.2
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• pp.139-148
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• 2010

The purpose of this study was to comparatively analyze the kinematic variables between the squash backhand and racquetball backhand strokes through three-dimensional cinematography. Three expert racquetball players and three expert squash players were involved in the data gathering process. The horizontal, vertical and lateral displacement of racket and trunk segment, intersegmental angular velocity of the wrist, elbow and shoulder joints, and the linear velocity of the racket were descriptively analyzed, and the followings were concluded. The racket of the squash backhand stroke showed an 'U' shaped movement where the racket moved rapidly downward and moved forward to make an impact and followed through to a front-top finish, while the racket of racquetball backhand stroke showed an 'O' shaped movement where the racket showed circular movement through the rear and bottom positions for the impact, and showed rotation through the lower-front and upper front to a upper-rear-ward finish during the follow-through. The peak velocity of racket was found before the impact point in the squash backhand stroke and at the impact point in the racquetball backhand stroke. For the final conclusion, for the squash backhand stoke, instructors might be better to make the racket move downward to make highest velocity before the impact and finished short follow-through, while for the racquetball backhand stroke, to make the racket move forward to make highest velocity at the impact and finished rather long follow-through.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.479-487
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• 2017

The purpose of this study was to identify the most influential soccer players by appling social network analysis. The subjects were the German national soccer team and the Korean national soccer team participated in the 2016 Brazil World Cup. The pass collected data provided by FIFA were analyzed by social network analysis using the Ucinet6 program and pass success rate. The results are as follows. First, the soccer player with a lot of passes had a high connection centrality in pass-through networks and high proximity. Second, the German national soccer team has appeared key players as Phillip Lahm and Kroos player, and a key player of the Korean national soccer team was Ki,S.Y. Third, the German national soccer team's quantitative indicator value of proximity center and pass success rate appeared higher than the Korean national soccer team's.