• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.109-117
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• 2018

Objective: To compare head and hand movement patterns during squash forehand motions between experts and less-skilled squash players. Method: Four experts and four less-skilled squash players participated in this study. They performed squash forehand swings and a VICON motion analysis system was used to obtain displacement and velocity data of the head and right hand during the movement. Mann-Whitney U-tests were performed to compare head and hand range of motion and peak velocity, and cross-correlation was performed to analyze the head-hand coordination pattern between groups in three movement directions. Results: In terms of head and hand kinematic data, experts had greater head range of motion during down swings than less-skilled squash players. Experts seemed to reach peak hand velocity at impact by reaching peak head velocity followed by hand peak velocity within a given temporal sequence. In terms of head-hand coordination patterns, both groups revealed high positive correlations in the medial-lateral direction, indicating a dominant allocentric coordination pattern. However, experts had uncoupled coordination patterns in the vertical direction and less-skilled squash players had high positive correlations. These results indicate that the head-hand movement pattern likely an important factor squash forehand movement. Conclusion: Analysis of head and hand movement patterns could be a key variable in squash training to reach expert-level performance.

• Journal of Sport and Applied Science
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• v.7 no.4
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• pp.13-18
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• 2023

Purpose: This study aims to determine what changes occur in body composition and performance by subjecting youth soccer players to weight training and combined training, which are known to be effective in improving anaerobic capacity, for 6 weeks. Research design, data, and methodology: This study was conducted on 30 high school soccer players from S City who had no current injuries or medical problems and had been registered as players with the Korea Football Association for more than 3 years. Subjects were divided into a weight training group (WTG, n=15) and a combined training group (CTG, n=15). Training lasted 6 weeks, and measurements were taken before and after training. Mean (M) and standard deviation (SD) were calculated to present the descriptive statistics of all dependent variables. Paired t-tests were used to test for within-group differences. Further, Independent t-tests were employed to test for between-group differences. Results: In terms of body composition, height significantly increased in WTG and CTG, and body fat percentage significantly decreased in CTG. As for performance, WTG's 20m sprint record decreased significantly. Conclusion: As a result, this study confirmed that weight training improved the 20m sprint ability of youth soccer players. Future research could provide more useful information by extending the study period and incorporating the physical characteristics of adolescents.

• Journal of International Academy of Physical Therapy Research
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• v.2 no.1
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• pp.244-250
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• 2011

The purpose of this study is to investigate whether there are differences in physique characteristics between the excellent domestic player groups in each sport player's, to prevent epidemiologic damage of musculoskeletal system and to provide fundamental data to improve performances for players. This study has performed for total 60 student players from Y University in Yongin, Gyeonggi-do, consists of 20 Kendo players, 20 Judo players and 20 Taekwondo players. We measured the length and circumference of arm, leg, body using Martin anthropometer to collect the data for 3 groups. There was significant difference in lower left arm length between player groups(p<.01), and Kendo players' right side femoral were longer than other 2 groups for leg length measurement(p<.01). Judo players' circumference for right/left stretched arm/bent upper arm were thicker than other 2 groups(p<.01). Taekwondo players' chest circumference were smaller than other 2 groups(p<.01), and Taekwondo players' right/left femoral circumference were thinner than other 2 groups(p<.05). From this study, it was found that there are physique characteristics differences between the Kendo, Judo and Taekwondo player groups. This indicates that repeated exercise for each sport player causes physique change, and it may cause epidemiologic damage of musculoskeletal system. It is recommended to perform balancing exercise prior to main exercise.

• Journal of Convergence for Information Technology
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• v.12 no.4
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• pp.166-176
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• 2022

The purpose of this study was to investigate the construct of Korean Version of Mental Toughness through Open-ended Questionnaire for soccer Players and coach. Data collection was inductively analyzed by distributing open questionnaires to 100 soccer players belonging to the Korean Football Association and 100 soccer coaches who participated in the training for obtaining a soccer coach's license. The resulting results are as follows. First, as a result of the inductive content analysis of korean version soccer players mental toughness, 11 factors were derived in the detailed area and 6 factors in the general area. Secondly, in the results on the mental toughness of Korean version soccer players according to soccer players and coaches, both players and coaches were found to be the highest factor, kkangdagu. I hope that the results of this study will be used as basic data for efforts to reduce the improving performance for soccer players and coaches.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.151-162
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• 2003

The purpose of this study was to investigate the frequency of sports injury among Korean junior elite golf players. The survey was made through the questionnaire which consist of eight categories and 280 valid answers were used to perform frequency analysis. The results indicated that 197 out of 280 participants experienced golf injuries (30%: during a game, 70%: during a practice) and 70% of them also experienced injuries within a year. The frequency analysis for the site of injury has shown that back was the most vulnerable area for all players(33%), followed by the right wrist, left shoulder and elbow for male players. Among female players, left wrist was the second weak site of injury, followed by the right wrist, right thoracic spine, and left shoulder. A few of them also have shown abnormal symptoms of ruptured lumbar disk, scoliosis, and lordosis and these injuries might be caused by the lack of flexibility and the fatigue due to over-practice. High frequency of wrist injury also demonstrated that excessive chopping or punching shot and poor environmental course conditions may cause this injury to be common. Overall, lack of warm up time, lack of strength and flexibility, and excessive amount of practice were the major reasons of injury for the junior elite golfers in Korea. The study also proved that these young Korean golfers actually had more chances to be faced with the injury than average. Thus, it is necessary to develop systematic and scientific methods of training, and prevention, treatment of these injuries with medical professionals.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.549-555
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• 2009

The purpose of this study was to quantify the isokinetic peak torque and range of motion at the shoulder in 8 national male volleyball players who played during the 2008 professional leagues. In this study the strength and range of motion data in the internal rotation(IR) and external rotation(ER) of shoulder joint were measured with isokinetic measurement system(Biodex Inc) and motion analysis system (Simi motion system Inc.) from 3 volleyball players with atrophy of the infrasupinatus and 5 volleyball players without atrophy of the infraspinatus. Peak torques were determined using isokinetic measurement on the shoulder joint rotator at the point of angular velocities of $60^{\circ}$/s. Significant difference was found in the peak torque, IR / ER ratio and the range of motion through assessment of the dominant shoulder between two groups. we recommended functional exercises that improve both external rotators strength and stretching exercise for internal rotation in the dominant side during the prevention programs in volleyball players.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.423-429
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• 2015

Objective : The purpose of this study was to investigate the effects of a body alignment correction program on asymmetrically developed squash players. Method : 30 experienced squash players who showed asymmetric body development, after evaluation of moire topography contour line shape, were involved in the experiment. All of them were right-handed and had more than five years of experience playing squash. Variables of body composition, moire topography and EMG were statistically compared between pre- and post- application of the 12-week body alignment correction program. The program consisted of 10-minute, left-handed forehand and backhand drive movements and 36 minutes performing 12 different yoga postures. Results : First, the body alignment correction program showed significant effects on the total weight, body fat percentage, and body mass index of the participants. Second, a decrease of right side inclined angles and an increase of left side inclined angles might result in a higher left-right symmetry rate and a better left-right balance; however the data was not statistically significant. Third, the EMG left-right deviation of erector spinae and latissimus decreased and the erector spinae muscle was thought to be more essential for vertebral movement and left-right asymmetry correction. Conclusion : A body alignment correction program, including yoga and opposite side exercises, could reduce left-right asymmetry.

• Korean Journal of Applied Biomechanics
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• v.17 no.4
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• pp.45-55
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• 2007

We investigated the biomechanics and characteristics of shoulder rotator muscles for professional woman volleyball players. The purpose of this study was to analyze the isokinetic peak torque and range of motion for shoulder joint rotation. We measured the strength and ROM of the internal rotation(IR) and external rotation(ER) of shoulders joint for nine professional woman Volleyball players and nine University students with Biodex and Simi-motion. 1. We measured peak torques for the shoulder joint rotator at angular velocities of 60/s and 180/s. It was found that the peak torques were significantly different between the two groups and also between the hands used. 2. At angular velocity of 60/s, IR/ER ratio of the shoulder joint was significantly different depending on the groups and the hands in use. There was a significant difference for 'Dominant side' at angular velocity of 180/s, but no significant difference for 'Non-dominant side' and the controls group. 3. Regarding the ROM of rotation of the shoulder joint group, IR was significantly different between the groups and the hands in use. 4. IR/ER ratio of the shoulder joint for Dominant side was quite different between the groups.

• Journal of Sport and Applied Science
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• v.5 no.2
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• pp.31-38
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• 2021

Purpose: A new form of sports human rights platform is needed for policy-related officials, athletes, leaders, and parents to easily share information on sports human rights and to promote communication between the sports community and the outside. Research design, data, and methodology: Participants were collected from athletes (n=3,007) who were registered in Korean Sport & Olympic Committee. Participants were asked to respond the survey items measuring their experiences of human right violations in sport. Descriptive analysis, t-test, and ANOVA were used to analyze data. Results: The platform should include information on prevention and safety of human rights violations during sports activities, procedures and methods for reporting damage, countermeasures, leader education programs, human rights protection guidelines, roles and supervision of sports organizations and institutions, and related statues. It can form a community as well as exchange information in the Internet space through the operation of bulletin boards by professional athletes, student athletes, parents, and leaders, and plays a role in crisis counseling or information provision. Given the reality that players can be blocked from the outside world, information communication channels on SNS can be a useful means of protecting and improving players' human rights. Conclusions: Therefore, it is necessary to provide a foundation for creating related platforms so that sports human rights sites or SNS can be operated voluntarily. Implications and future directions were discussed.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.455-461
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• 2014

The purposes of this study were to reveal the kinematic and kinetic difference of hard ground soccer shoe, firm ground soccer shoe and soft ground soccer shoe. Soccer players were shoes of varying stud designs with some preferring the bladed studs while others opting for the conventional studded stud. Statistics were used one way-ANOVA and Tukey's Honestly Significant Difference Method. Seven healthy college soccer players were attended a test. All parameters were recorded using the Zebris system. Spatio-temporal variables were no significant difference. Lateral symmetry was statistically significant differences (p<.05). Vertical GRF parameters were no significant difference. Medial midfoot pressure, lateral midfoot pressure and central forefoot pressure were statistically significant differences (p<.05). This study demonstrates that playing surface significantly affects difference soccer shoes during soccer game. Furthermore, epidemiological investigation is warranted to determine the effects of playing surfaces on sport specific injury mechanisms.