• Physical Therapy Rehabilitation Science
• /
• v.7 no.1
• /
• pp.13-17
• /
• 2018

Objective: This was a correlation study for predicting the power to improve the distance of golf players and developing an effective power program. Design: Cross-sectional study. Methods: The subjects of this study were 24 healthy males and females in their 20s and 30s who were golf athletes living in Seoul and Gyeonggi-do. In the Titleist Performance Institute (TPI) Level 1 test, the twelve swing characteristics include components of stability, mobility, body conditioning ability, and balance. The power test consisted of a vertical jump (VJ) in order to examine the power of the lower body, the seated chest pass (SCP) was used to examine upper body power, and the sit up and throw (SUAT) was used to examine the power of the upper body and core for the TPI Level 2 test. Results: The results of this study showed that the 90/90 was correlated with VJ, SUAT, and SCP scores (p<0.05). Single leg stance was correlated with VJ, SUAT, over head deep squat, and bridge with leg extension were correlated with VJ (p<0.05). The toe touch was correlated with SUAT results (p<0.05). Conclusions: The results of this study showed that the TPI Level 1 test and power test were correlated with the performance of the golf players. Future studies have shown that fitness program development and further research are needed.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.2
• /
• pp.157-165
• /
• 2015

Object : The goals of this research were to make Performance Enhanced Model(PE) taken the largest performance index (PI) through artificial variation of principle components calculated by principle component analysis for trial data, and to verify the effect through comparing kinematic factors between trial data (Raw) and PE. Method : Ten subjects (5 men, 5 women) were recruited and 80% of their maximal record was considered. The PI is a regression equation. In order to develop PE, we extracted Principle components from trial position data (by Principle Components Analysis (PCA)). Before PCA, we made 17 position data to 3 row matrix according to components. We calculated 3 eigen value (principle components) through PCA. And except Y (medial-lateral direction) component (because motion of Y component is small), principle components of X (anterior-posterior direction) and Z (vertical direction) components were changed as following. Changed principle components = principle components + principle components ${\times}$ k. After changing the each principle component, we reconstructed position data using the changed principle components and calculated performance index (PI). A Paired t-test was used to compare Raw data and Performance Enhanced Model data. The level of statistical significance was set at $p{\leq}0.05$. Result : The PI was significantly increased about 12.9kg at PE ($101.92{\pm}6.25$) when compared to the Raw data ($91.29{\pm}7.10$). It means that performance can be increased by optimizing 3D positions. The difference of kinematic factors as follows : the movement distance of the bar from start to lock out was significantly larger (about 1cm) for PE, the width of anterior-posterior bar position in full phase was significantly wider (about 1.3cm) for PE and the horizontal displacement toward the weightlifter after beginning of descent from maximal height was significantly greater (about 0.4cm) for PE. Additionally, the minimum knee angle in the 2-pull phase was significantly smaller (approximately 2.7cm) for the PE compared to that of the Raw. PE was decided at proximal position from the Raw (origin point (0,0)) of PC variation). Conclusion : PI was decided at proximal position from the Raw (origin point (0,0)) of PC variation). This means that Performance Enhanced Model was decided by similar motion to the Raw without a great change. Therefore, weightlifters could be accept Performance Enhanced Model easily, comfortably and without large stress. The Performance Enhance Model can provide training direction for athletes to improve their weightlifting records.

• The Journal of Korean Physical Therapy
• /
• v.15 no.2
• /
• pp.75-84
• /
• 2003

The purpose of this study was to review of mechanism and application methodology about mental practice. The mental practice is symbolic rehearsal of physical activity in the absence of any gross muscular movements. Human have the ability to generate mental correlates of perceptual and motor events without any triggering external stimulus, a function known as imagery, Practice produces both internal and external sensory consequences which are thought to be essential for learning to occur, It is for this reason that mental practice, rehearsal of skill in imagination rather than by overt physical activity, has intrigued theorists, especially those interested in cognitive process. Several studies in sport psychology have shown that mental practice can be effective in optimizing the execution of movements in athletes and help novice learner in the incremental acquisition of new skilled behaviors. There are many theories of mental practice for explaining the positive effect In skill learning and performance. Most tenable theories are symbolic learning theory, psyconeuromuscular theory, Paivio's theory, regional cerebral blood flow theory, motivation theory, modeling theory, mental and muscle movement nodes theory, insight theory, selective attention theory, and attention-arousal set theory etc.. The factors for influencing to effects of mental practice are application form, application period, time for length of the mental practice, number of repetition, existence of physical practice.

• Journal of Nutrition and Health
• /
• v.39 no.3
• /
• pp.299-306
• /
• 2006

This study was done to investigate the use of nutritional supplements (NS) in Korean elite soccer players using an anonymous questionnaire. NS were classified into health supplements, manufactured health food supplements, chinese medicines & tonic foods, and nutrient supplements. Information was sought on the type of NS and factors that might influence supplement use including selected demographic parameters and health related variables. The data were collected from 241 athletes (aged $24.6{\pm}3.8$ years) in 9 professional soccer club. The prevalence of NS use among the subjects was 81.3%. Health supplements were used most frequently and nutrient supplement drug was the second one. Among the health supplements, weight/muscle gainer and calorie replacement product were most frequently used. Vitamin supplements were most frequently used among all nutrient supplement drugs. Users of NS were higher age (p<0.05) duration of exercise (p<0.05), and income (p<0.05) than non-users. The married (p<0.05) and a member of K-league (p<0.01) tended to have higher prevalence of NS use. The main adviser of NS were family (55.3%) and oneself (39%) instead of coach or sports nutritionist. Although NS use, only 26.2% certainly check up nutritional information on their used NS. Among the subjects, 84.5% of them felt that NS use were improved athletic performance, and 86.5% of them will to keep on taking supplement. These data suggest that a large number of elite soccer players use NS and these players may require education about healthy nutritional supplement practice and on the proper use of nutritional supplements.

• Journal of computational fluids engineering
• /
• v.21 no.3
• /
• pp.71-76
• /
• 2016

In speed skiing, aerodynamic forces play an important role in determining performance of the skier. To predict aerodynamic effects of the posture of the skier on alpine downhill skiing, we constructed equation of motion of the skier and performed the corresponding CFD simulations. Comparing drag and lift of three different skier postures, it has been shown that drag decreases significantly by tucking upper body to lower body and stretching arms forward. Also, aerodynamic lift which worked as downforce in standing posture worked upward in tuck posture, reducing friction force between snow and ski. This indicates that tuck posture have advantages over standing posture in dual mechanism, namely by reducing drag and also increasing lift. By this two-dimensional initial study we could reveal the general tendency of the aerodynamic force over the skier's body. This study not only provides a theoretical foundation for the athletes to understand the aerodynamic effects of skier postures but also shed a light on towards more accurate and rational three-dimensional CFD simulation of skiers in the near future study.

• The Journal of Korean Physical Therapy
• /
• v.14 no.4
• /
• pp.423-440
• /
• 2002

The purpose of this study is to investigate the conception and developmental process of stretching in sports physical therapy. This study is to find conception of stretching, feature and effect, principles and fundamental rule, consideration of enforcement and developmental process in order to use the basic material which is very helpful in the every field and the scene of sports needing stretching. Flexibility is the ability to move muscles and joints through their full ranges of motion. Flexibility is developed by stretching. About player who insufficiency of flexibility, patient and disabled person who restrict of range of motion, older adult who reduce of flexibility, promote of flexibility for upgrading stability and efficiency of body on the based of scientific principles is completed by stretching. The method of stretching has been developed with passive stretching, CR, PNF stretching, PIC stretching, MET stretching in the order. The effects that we can get through stretching are as follows : 1. Enhance physical fitness. 2. Optimize learning, practice and performance of many types of skilled movement. 3. Increase mental and physical relaxation. 4. Promote development of body awareness. 5. Reduce risk of joint sprain or muscle strain. 6. Reduce risk of back problem. 7 Reduce muscular soreness. 8. Reduce the severity of painful menstruation for female athletes. 9. Reduce muscular tension. 10. Advance recognition of body.

• Korean Journal of Clinical Laboratory Science
• /
• v.52 no.1
• /
• pp.36-44
• /
• 2020

With the advent of westernized diet and a lack of exercise, young female college students are paying more attention to their bodyweight and health. Whole-body vibration has been demonstrated to be a suitable training method for improving knee extension maximal strength in young female athletes, as well as the gait performance in elderly women. This study aimed to evaluate the effects of a vertical vibration intervention on the physical fitness and postural balance in young females. Fifty-four young women were recruited; all subjects were randomly assigned to the intervention group and control group. The intervention group underwent vertical vibration with a platform for 12 weeks. The results showed that body mass index and body fat percentage had decreased (P<0.05). In addition, their muscle endurance as indicated by a sit-up test and their flexibility as indicated by a sit-and-reach test were both increased. With regard to postural balance, their 30-second sit-to-stand and timed up and go test results were improved. At the same time, their mean single-leg stance with eyes closed time increased (P<0.05). However, there were no significant differences, meanwhile, for the control group. Overall, the results showed that the whole body vibration (WBV) intervention had some beneficial effects on physical fitness and postural balance in young women.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.2
• /
• pp.125-130
• /
• 2013

Although the electronic body protector has been officially adopted by the World Taekwondo Federation(WTF) in 2006, no scientific information is available about the reliability of its performance. The purpose of this study, therefore, was to investigate the relationship between the impact value of electronic body protector and the impact force of force platform. Male collegiate Taekwondo athletes([MCTA], n=21) and male collegiate Taekwondo students([MCTS], n=20) volunteered to participate in the study. Each subject performed the apchagi, dollyeochagi and dwichagi on the force platform and the electronic body protector. At the apchagi, it showed that MCTS(about 4,700 N) generated more maximum kick force than MCTA(about 3,900 N), but it expressed that MCTA(about 5,300 N) generated more maximum kicking force than MCTS(about 4,400 N) at the dwichagi. At the apchagi and the dwichagi, it indicated the high coefficient of correlation(over r=.8) which supports higher explanation force the relationship between the impact value of electronic body protector and the impact force of force platform, but there was no statistically significant difference at the dollyeochagi.

• Korean Journal of Applied Biomechanics
• /
• v.28 no.2
• /
• pp.93-100
• /
• 2018

Objective: The purpose of this study is to analyze the kinematic characteristics of the national speed skaters in the curve phase of 500-m race. Method: Seven national skaters participated in the study. Race images were acquired using a high - speed camera, and the three-dimensional motion was analyzed. Results: For skaters, whose average velocity in the curve phase is high, the velocity of entry into the straight phase was also fast. The fast skaters showed a larger maximum angle of extension of the knee joints than the relatively slow skaters, and the trunk ROM was smaller. Fast skaters tended to match the timing of the movement of the lower limb with the pelvis, while slow skaters tended to rotate the left pelvis backward. The velocity of the curve phase did not show a clear relationship with stroke time, average trunk angle, and lap time. Conclusion: It is important to skate close to the inner line, keep the trunk ROM below 10 degrees, extend the knee angle to over 160 degrees, and match the movement of the pelvis and lower limb to accelerate in the curve phase. The average velocity of the curves was fast for many athletes, but the competition rankings were low. Therefore, it is possible to improve the performance by optimizing the start technique, the running characteristics of the straight phase, and the physical factors.

• Journal of the Korea Convergence Society
• /
• v.10 no.7
• /
• pp.191-198
• /
• 2019

This paper investigates different types of leadership found in foreign coaches in charge of the Korean national soccer team. To that end, news articles published during the tenure of those coaches were crawled for analysis. The analysis highlighted the following results. First, successful sports leaders showed their own specific types of leadership. Second, failed sports leaders showed specific types of leadership. The findings have the following implications. The leadership established based on the analysis results have practical implications in that they suggest the types of effectiveness leadership that are required of sports leaders in managing and leading athletes whilst generating tangible results and performance.