• PNF and Movement
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• v.18 no.3
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• pp.343-350
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• 2020

Purpose: The purpose of this study was to determine how a shoulder complex stabilization exercise affects ball control and ball speed in elementary school baseball players with an instable scapula. Methods: The subjects of the study were 16 baseball players attending S elementary school in Kwangju Metropolitan City. A shoulder complex stabilization exercise was conducted three times per week for one hour for four weeks. Then, the participants were divided into a scapular instability group or stability group based on their lateral scapular slide test scores. The measurement tool was measured using the target, the ball speed tester (PR1000-BC). All inspections were measured before and after the mediation period to examine the change in the subjects according to the mediation period. Results: As a result of measuring ball control, there was a statistically significant difference in the variation over time (p < 0.05), and there was no statistically significant difference in the interaction between time and group (p > 0.05). As a result of the test of effectiveness between subjects, there was no statistically significant difference found among the groups (p > 0.05). In terms of ball speed, there was no statistically significant difference found in the variation over time (p > 0.05) as well as in the interaction between time and group (p > 0.05). In terms of the effectiveness between subjects, there was no statistically significant difference found among the groups (p > 0.05). Conclusion: It was found that the shoulder complex stabilization exercise could improve ball control for elementary school baseball players. It is believed that this will help prevent and solve possible sport damages experienced during training or competitions, thereby helping athletes use training methods to improve their exercise capacity and continue their careers.

• 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.21 no.5
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• pp.585-593
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• 2011

The purpose of this study was to analyze, from a kinematical point of view, the high jump techniques of three women's high jump winners at the IAAF World Championships, Daegu 2011. The trends for the techniques of the world's top high jumpers were examined, with a view toward adapting these techniques to the physical characteristics of Korean women's high jumpers. It was valuable that Di Martino, who was the shortest in height, was able to win a medal by using a single arm swing take-off technique, along with a half flexed leading leg swing to attain a deep arch and clear the bar. This showed that the world's top athletes used jumping techniques with no decrease in the run-up velocity at the take-off. Furthermore, It appeared that the knee joint angle at take-off had a direct effect on the body position at take-off (H1).

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.162-167
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• 2021

Objective: This study aimed to identify the different wind speed categories and competitive level among windsurfers through GPS variables to provide the useful information on the development of training programs for enhancing windsurfers' performance. Method: Data from 69 female athletes who participated in 27 races during the 2018-2019 windsurfing season were used for the analysis. Average board speed, total race time, total distance, upwind race time, downwind race time, beam reach race time were collected through GPS. Unconfirmed data were excluded along with penalty point data. The wind conditions were classified as light, light to medium, medium, medium to heavy, and heavy wind, the competitive levels were classified as level 1, level 2, and level 3. Results: As for the average board speed, the level 1 or level 2 group showed higher board speed than the level 3 group in all wind conditions except for the light wind. The total race time and upwind race time showed less time in level 1 or level 2 group than level 3 group in all wind conditions. The total distance, downwind race time and beam reach race time showed less distance and time in level1 group than level 3 group under sufficient wind conditions. Conclusion: Our results show that the aerobic capacity to sustain pumping during upwind course in wind conditions below 15 kts effects performance. In wind conditions of 15 kts or more, indicated that the board control for the fast board speed and small distance required during up, down, beam reach courses had an effect on competition performance. This information can be provided to windsurfers and coaching as basic data for training programs to improve performance.

• Korean Journal of Community Nutrition
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• v.24 no.1
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• pp.47-59
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• 2019

Objectives: Young athletes require adequate nutrition to maintain their athletic performance, growth and health. This study examined the status and needs of nutrition management and meal services for student athletes among the athlete's parents. Methods: The subjects were parents of elementary, middle, and high school athletes (n=323) from 18 schools participating mainly in the Sports Food Truck. The questionnaire included general characteristics, status and needs on nutrition management and meal service for student athletes, and satisfaction with the Food Truck. The survey was done during 2018. The data were analyzed according to the school groups using a ${\chi}^2-test$ or ANOVA. Results: Approximately 45% of subjects had difficulty in the nutrition management of athletes, and 87.1% had not received nutrition education. Approximately 74% wanted nutrition education held for athletes, and mainly wanted topics on nutrition management for health and eating for athletic performance. The preferred methods were lectures and cooking activity. The responses on the necessity of nutrition education for athletes, desired education topics, and desired times for education differed significantly according to the school groups (p<0.05). Most subjects also wanted nutrition information mainly through SNS. In the athlete's meal, breakfast and snacks were highlighted as the meal to supplement. Approximately 90.3% responded that providing a meal service is necessary. The subjects preferred snacks before/after exercise and dinner if a meal service was provided. They preferred Korean food, followed by snacks, and a dish meal. As the meal type, the subjects wanted the Food Truck and packed meal. The responses on necessity of a meal service (p<0.05), preferred food (p<0.001), and meal type (p<0.001) in the meal service differed significantly according to the school groups. Approximately 43% were satisfied with the Food Truck and 50.8% responded as average. They made suggestions for the Food Truck in terms of foods, operations and frequency. Conclusions: Based on the study results, nutrition education and meal service may support nutrition for student athletes considering the needs of the parents according to the school groups.

• Journal of Korean Orthopaedic Sports Medicine
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• v.5 no.1
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• pp.69-74
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• 2006

Purpose: To perform the retrospective analysis of the sports injuries sustained by the college Taekwondo athletes in the respect of the injury patterns, mechanism of injury and clinical outcome Materials and Methods: This study is based on 47 out of 49 college Takwondo athletes, who had experienced the Takwondo related musculoskeletal injuries severe enough to visit the clinic for medical treatment. The mean age at the time of injury was 18.8 years and 39 were males and 8 females. The Taekwondo career was average 9.6 years and the injuries were sustained at average 6.7 years of their career. The injuries were analyzed by the detailed interview with thorough physical examination. Results: Forty-seven Taekwondo athletes in the study experienced average 1.8 injury/person (total 85 cases) with 26 persons of one time experience(55.3%), 11 persons of 2 times(23.4%),4 persons of 3 times (8.5%),5 persons of 4 times (10.6%) and 1 person of 5 times (2.2%). Injuries occurred during training in 50 cases (58.8%), while during match in 35 cases (41.2%). Injuries occurred during the attack phase of the match are 26 cases (31.7%) while 49 cases (57.6%) during the defense phase. As for the pattern of injury, fracture was the most common with 49 cases (57.6%), followed by ligament injury with 21 cases (24.7%). The upper extremity injuries were 32 cases (37.7%) while the lower extremity injuries were 44 cases (51.8%) Mode of medical treatment were operation in 15cases(17.7%), cast in 21 cases(24.7%), splint in 33 cases (38.8%), physical therapy in 15cases(17.7%) and acupuncture in 1 case(1.1%) Conclusion: Almost all the college Taekwondo athletes (96%) experienced sports injuries severe enough to receive medical treatments with the fracture being the most common injury pattern. The injuries occurred more commonly during the defense phase of the competition.

• Korean Journal of Applied Biomechanics
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• v.21 no.5
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• pp.541-550
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• 2011

The purpose of this study was to investigate the kinematic characteristics of the $5^{th}$ and $6^{th}$ hurdle clearances during the final of the 100-m hurdles event at the IAAF World Championships, Daegu 2011. To this end, the hurdling motions of the top 4 ranked female hurdlers in the competition were analyzed. A total of 12 cameras were used to record their motions, with a sampling frequency of 120 Hz. The cameras were calibrated using $11{\times}2{\times}1\;m$ control objects that covered all of the lanes ($1^{st}{\sim}8^{th}$ lanes). After analyzing all the data, we arrived at the following results. For the take-off phase, a negative relationship between the take-off time (CT) and athlete's rank was found. In addition, the average distances from the hurdle to take-off (L1) were shown to be 2.23 m and 2.17 m for the $5^{th}$ and $6^{th}$ hurdles, respectively. For the distance from the hurdle to landing (L2), Pearson ($1^{st}$ rank) and Carruthers($2^{nd}$ rank) showed inconsistent patterns whereas Harper ($3^{rd}$ rank) and Porter ($4^{th}$ rank) showed consistent patterns. All althetes revealed similar 3 steps patterns between hurdles, which consisted of a shorter $1^{st}$ step, longer $2^{nd}$ step and shorter $3^{rd}$ step.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.49-58
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• 2009

This study aims to analyze the association between the center of mass(C.O.G) and ocular movement(E.O.G) according to the success and failure in the left turn motion on the balance beam, targeting three female gymnasts. When successful, the left-right C.O.G was moved to the left, which was a rotational direction until such time as the body rotated $180^{\circ}$, whereas there appeared to be a greater movement during failure; thus, it was shown to affect the maintenance of dynamic postural control. In case of the subsequent left-right turning motion of E.O.G, this matches the previous theory that the eyeball moves against the direction of rotation of the body. However, there was a difference at the time of movement, and a clear difference emerged in the success and failure in this study. Also, in the E.O.G in the up-down direction, a movement during failure showed a pattern of down direction in most cases; thus, it is deemed to affect the failure. Therefore, the kinetic postural control and E.O.G are supposed to affect the success and failure in a landing, which is the most importantly evaluated movement on the balance beam, in mutual association.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.31-39
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• 2007

The purpose of this study was to observe the kinematic pattern of elite women 100m hurdler race from start to finish and analyze how the change of horizontal velocity makes an influence on the athletes' performance. The analysis was based on the performance of Korean elite 100m hurdler A and international elite hurdlers B and C. Following results were drawn from the analyzation of elite 100m hurdlers' technical characteristics; During the race, hurdler A made more than 8 m/s of horizontal velocity at the 3rd, 4th, 6th, and the 7th hurdle. The horizontal velocity peaked at the 4th hurdle with 8.23 m/s. On the other hand, hurdler B and hurdler C maintained more than 8 m/s of horizontal velocity from the 2nd hurdle through the 10th hurdle. Hurdler B's fastest horizontal velocity was 8.67 m/s from the 6th to the 7th hurdle and hurdler C's fastest horizontal velocity was 8.85 m/s from the 5th to the 8th hurdle. From the start line to the 3rd hurdle, the times achieved by hurdlers A, B, and C were 4.90 sec, 4.65 sec, and 4.52 sec. In the middle of the race, which is from the 4th hurdle to the 7th hurdle, hurdlers A, B, and C ran in 9.10 sec, 8.60 sec, and 8.38 sec. And the latter part of the race to the 10th hurdle, the times hurdlers A, B, and C hit were 12.32 sec, 11.66 sec, and 11.32 sec. To the finish line, it took 1.15 sec for hurdler A, 1.1 sec for B, and 1.06 sec for C. Hence, to set the record of sub-13 sec, hurdler A should improve her acceleration from the start line to the 1st hurdle with the speed more than 5.4 m/s and should maintain more than 8 m/s of horizontal velocity from the 2nd hurdle through the 10th hurdle. In addition, hurdler A should improve her speed endurance to minimize the deceleration of horizontal velocity from the 4th hurdle to the final hurdle. If hurdler A could shorten 0.05 sec of time in each hurdle section, she would be able to set the record under 13 seconds.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.3
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• pp.1-9
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• 2018

PURPOSE: The purpose of this study was to determine the effect of exercise therapy on low back pain (LBP), the function of paraspinal and abdominis muscles, and the sacrohorizontal angle as seen on the radiographs of the lumbar spine in a young female golf player with LBP. METHODS: This case report describes an 11-year-old female golfer who presented with LBP. The exercise therapy program comprised lumbar joint mobilization, lumbar spine flexion distraction, abdominal bridge, plank, side plank, and single-leg extensions from a 4-point kneeling position for 40 min/day; this was done twice a week for 8-weeks. LBP [visual analog scale (VAS) and Oswestry disability index (ODI)] and function of paraspinal and abdominis muscles [Ito test, curl-up test, $90^{\circ}$ stop test, squat test, opened eye one leg stance test (OEOL), and closed eye one leg stance test (CEOL)] were measured before and after 4 and 8 weeks of exercise therapy. The radiographs were analyzed for the lumbar Cobb's angle and sacrohorizontal angle before and after 8 weeks of exercise therapy. RESULTS: After 4 and/or 8 weeks of exercise therapy, VAS and ODI scores decreased; results for the Ito test, curl-up test, $90^{\circ}$ stop test, squat test, and OEOL and CEOL of muscle function improved; and the lumbar Cobb's angle and sacrohorizontal angle improved. CONCLUSION: These results suggest that exercise therapy improves LBP, muscle function, and radiographic parameters associated with LBP in young golf players. These findings have clinical implications for exercise therapy in young female golf players who have LBP.