• 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.17 no.4
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• pp.149-156
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• 2007

The purpose of this study was to compare the world class women's hurdlers with kinematic variables Lee Yeon-Kyoung's in the 100m hurdle. Among korea elite female hurdler, Lee Yeon-Kyoung was participated as a subject. Eight JVC video cameras(GR-HD1KR) were used to film the performance of Lee Yeon-Kyoung at a frame rate of 60fields/s. The real-life three-dimensional coordinate data of digitized body landmarks were smoothed using a fourth order Butterworth low pass recursive digital filter with an estimated optimum cutoff frequency of 7.4Hz. After analyzing and comparing Lee Yeon Kyung's kinematic variables with the world top class hurdlers in the woman's 100m hurdle run, the following conclusions were obtained. 1. Lee should be able to increase the speed with over 5.4m/s from start to first hurdle and then maintain the speed range from 8.33m/s to 8.67m/s until 10th hurdle. Lee should have to maintain the speed with 8.51m/s from 10th hurdle to finish line. 2. Lee has to reach her maximum running speed at 5th hurdle and then has to shorten running time with 0.5sec between hurdles. 3. Lee should be able to run around 2.5sec from start to frist hurdle and then maintain under 1.00sec following phases. Lee should be able to maintain under 1.10sec from 10th hurdle to finish line. 4. Lee needs to control a consistent takeoff and landing distance pattern, Lee needs to lower the height of the center of gravity of the body with 0.33m when she clears the hurdles.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.59-66
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• 2009

The purpose of this study was to evaluate flatness of swing plane and determine swing plane type using 3-D swing plane analysis from young elite male golf players. This study also investigate the possibility of determination of swing plane using other kinematic parameters except flatness. As results, no correlations was found between flatness and handicap. Comparison of flatness between single plane and multiple plane swing group were performed and found a significant difference. The error range of flatness, 10cm, which was used for distinguish swing plane type was effective since significant differences were found at MB, EB, and EF. These differences were typical characteristics to classify two swing styles. Other kinematic parameters such as unit vector components of shaft and displacement of shaft end point also compared per event but found no significant differences. However, the moving patterns of these parameters during a golf swing showed such characteristics of each swing plane type well that these parameters could be used to determine swing style as an indirect barometers.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.45-53
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• 2006

The purpose of this study was to analyze exercise related mechanical variables according to performance levels and Kumi-kata types in elite judo players (G1) and non-elite judo players, namely university players (G2). To achieve this purpose, three players in G1 whose main special skill was Morote-Seoinage and three university judo players(G2) was selected as comparative group. Then they were examined for distinguishing A and B types of Kumi-kata. Analyzed variables were the time required to show skills, knee degree, elbow degree. After analysing this study, conclusions were derived as follows. 1. In total necessary time of showing skills according to group of Kumi-kata type, G2 was longer than G1 in both A type (20.9%) and B type (23.7%). In necessary time of phase, in only 3P, G1 was shorter than G2 in A type (50%) and B type (75%). There was no difference in time required of 1P and 2P according to Kumi-kata type of group and in only 3P, B type was shorter than A type in both B type (75%) of G1 and B type (50%) of G2 2 There was no difference in elbow degree of offensive arm according to group of Kumi-kata type, however in A and B types, G1 could use skills by extending in kake phase, but G2 could use skills by bending. Elbow degree of offensive arm according to Kumi-kata type of group showed difference in E1. and F2 of G1. A and B types of G1 extended elbow degree in Kake phase, but G2 bent elbow degree so exercise program which could movable range extensively in Kake phase is needed.

• Korean Journal of Applied Biomechanics
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• v.22 no.4
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• pp.387-394
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• 2012

The purpose of this study was to compare and analyze the finger pressure and kinematic variables in the forehand hairpin net shot between skilled elite players and less skilled recreational players. Eight elite players(age: $18.1{\pm}0.8yrs$, height: $176.8{\pm}1.5cm$, weight: $640.9{\pm}48.6N$) with minimum of 6 years of experience and eight recreational players(age: $27.9{\pm}1.6yrs$, height: $177.1{\pm}6.1cm$, weight: $820.5{\pm}62.8N$) with less than one year experience were recruited in this study. For each trial being analyzed, four critical instants were identified from the video recordings: Right heel contact1 (E1), Right toe-off (E2), Right heel contact2 (E3), and Shuttlecock Impact (E4). Each hairpin net shot was broken into consecutive phases: E1~E2 (Right Landing Phase: RLP), E2~E3 (Sliding Step Phase: SSP), and E3~E4 (Impact Phase: IP). Temporal parameters, shuttlecock speed, linear and angular kinematics of body segments, and finger pressures were computed for this study. The results showed that The finger pressure of the ring finger and the middle finger for the skilled group during an impact had significantly greater than those of unskilled group. It is possible that all fingers were not used in the same manner when the racket was gripped in forehand hairpin. The result also suggested that the ring finger and the middle finger pushed the racket from top to bottom while having the mid-phalanx and proximal phalanx of index finger as an axis.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.555-564
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• 2021

This study aims to examine the relationship between the expertise of track and field coaches, the team atmosphere, and athletic satisfaction in elite sports. To achieve this research purpose, data were collected using questionnaires from 221 student athletes from junior high to university students registered with the Korea Association of Athletics Federation in 2021 and collected using Google online questionnaires in consideration of the pandemic situation. For data processing, frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis were performed using the statistical program SPSS 22.0, and the following conclusions were drawn. First, it was found that the expertise of the athletics coaches had a positive (+) effect on the team atmosphere. Second, among the sub-factors of athletics coach expertise, only athlete management was found to have a negative (-) effect on daily life satisfaction, a sub-factor of athletic satisfaction. Third, it was found that among the sub-factors of the team atmosphere, only role characteristics and leader characteristics had a positive (+) effect on social approval satisfaction, a sub-factor of athletic satisfaction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.366-373
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• 2005

This study was carried out to investigate the self-reported health and eating habit of the elite female adolescent athletes in Incheon. The subjects were 102 elite female athletes of middle and high schools located in Inchon. A self-administered Questionnaire was used for this cross-sectional survey. Statistical analysis by two-way ANOVA was performed to discriminate between the main effects of age (as middle and high school athletes) and sports type, and their interaction. As use of nutritional supplements, 35.8% of the total subjects took vitamin and iron supplements and 62.5% of field and track athletes took vitamin and iron supplements. While mental stress related to exercise was much in fencing ＆gt; shooting ＆gt; field and track ＆gt; swimming athletes, physical burden during training was higher in swimming ＆gt; field and track ＆gt; fencing ＆gt; shooting athletes. More than half of the subjects showed irregular menstrual cycle. As the most severe problem of eating habit, they reported skipping meal ＆gt; overeating ＆gt; prejudiced meal ＆gt; preference to salty and spicy foods. More than half of the subjects skipped meal over three times per week. Fencing and shooting athletes showed very significantly higher frequency of skipping meal and more irregular breakfast time compared to those of other sport types. As for snack, they ate cookies, carbonated drink, chocolate, candy ＆gt; milk, yogurt, ice cream ＆gt; cake, bread, rice cake ＆gt; fried noodle ＆gt; hamburger, pizza. Therefore, nutritional counseling and education by sport type are necessary for health and good eating habit of these elite female adolescent athletes.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.47-65
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• 2003

The purpose of this study was to investigate the differences of the kinematical and the kinetical factors that calculated from preflight to postflight of salto forward straight 3/2 turn motion between skitters and less-skitters. four S-VHS video cameras operating at 60Hz were used to record the performances. five elite male gymnasts were participated in this study as subjects. three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation method. The digitized body landmarks were smoothed using a Butterworth second order with low pass digital filter and a cutoff frequency of 10Hz. 1. A skitter, got a high score for performance, showed shorter time and faster horizontal velocity than a less-skitter at the board contact. also, a skitter extended quickly his knee and hip joint after contacting board for preflight phase. 2. A skitter revealed faster time and horizontal velocity the vault from taking off board than a less-skiller. A skitter took a long time and high distance to get the vertical peak compared with a less-skiller. 3. For the second phase, a skitter, who executes the most optimal motions among the subjects, displayed a long flight time, a high height, and a far flight distance as well as maintaining consistent horizontal speed even at the peak of post flight. On the other side, a less-scorer displayed a slow vertical velocity, distance and a short time at the point of take-off from vault as well as low height at the peak of post flight.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.393-400
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• 2020

This study used a three-dimensional motion analysis system for 15 elite tennis players (male 8, female7) to identify the relevance of scapula movement to shoulder pain. During the flat serve, the angular velocity and joint moment of scapula anterior/posterior tilt, downward/upward rotation, internal/external rotation were calculated and this was compared between groups. As a result, the maximum angular velocity for the anterior and posterior tilt tended to be higher in control group(CG) than in the shoulder pain group(SPG), and the maximum angular velocity for internal and external rotation in all phases except the follow-through phase was higher than that of CG. The maximum moment for the anterior and posterior tilt in the late coking phase was statistically significantly higher than that of SPG, the joint moment for the downward and upward rotation of the coking phase was statistically significantly lower than that of CG, and the moment for the internal and external rotation, the SPG was found to be lower than that of CG in the whole phases.

• Korean Journal of Applied Biomechanics
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• v.31 no.4
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• pp.290-296
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• 2021

Objective: The purpose of this research is to examine the effects of three types of different running shoes with different properties on impact variables (PVRGF and VLR) and the lower extremity joint's dynamic stability variables (LyEs of DPA, IEA, FEA, DPAV, IEAV, and FEAV) during running. Method: The participants in this research were 12 males (Age: 22.0 ± 3.3 years, Height: 177.2 ± 4.1 cm, Weight: 74.3 ± 9.6 kg). One type of N company's running shoes and two types (FA, FB) of F company's running shoes were used. As for the properties of the running shoes, thickness (mm), dwell time (ms), peak acceleration (m/s2), and energy return (%) were measured. The motions running at 3.5 m/s on a treadmill (Instrumented treadmill, Bertec, USA) wearing each type of running shoes were analyzed. Results: Although the VLR of the thick running shoes (FB) was smaller than that of the other running shoes (N, FA), the LyEs of PVGRF and DPA were larger (p<.05). Even though the running shoes' dwell time (i.e., impact absorption time) and peak acceleration showed a positive correlation with the LyEs of DPAV, IEAV, and FEAV, the energy return showed a negative correlation (p<.05). Conclusion: Our results indicated that the running shoes with excellent impact absorption function are predicted to be suitable for running beginners who need to reduce the burden of the lower extremity joint during running. The running shoes with excellent energy return are expected to be suitable for mid-and long-distance running elite athletes or marathoners to whom stability and consistency are essential during running.