족저압력분포 측정장비를 이용한 골프 스윙시 족저압 분석

이동기,이중숙,이범진,이훈식,김용재,박승범,주종필 한국운동역학회 2005 한국운동역학회지 Vol.15 No.1

D. K. LEE, J. S. LEE, B. J. LEE, H. S. LEE, Y. J. KIM, S. B. PARK, J. P. JOO. PIantar foot pressure analysis during golf swing motion using plantar foot pressure measurement system. Korean Journal of Sport Biomechanics, Vol. 15, No. 1, pp. 75-89, 2005. In this study, weight carrying pattern analysis and comparison method of four foot region were suggested. We used three types of club(driver, iron7, pitching wedge). This analysis method can compare between top class golfer and beginner. And the comparison data can be used to correct the swing pose of trainee. If motion analysis system, which can measure the swing speed and instantaneous acceleration at the point of hitting a ball, is combined with this plantar foot force analysis method, new design development of golf shoes to increase comfort and ball flight distance will be available. 1. Address acting, forces concentrated in rare foot regions and lateral foot of right foot. Back swing top acting, relatively high force occurred in medial forefoot region of left foot and forefoot region of right foot. Impact acting, high force value observed in the lateral rarefoot region of left foot and medial forefoot region of right foot. Finish acting, force concentration observed on the lateral region and rarefoot region of left foot. 2. Forces were increased in address of right foot with clubs length increased. All clubs, back swing top acting, high force value observed in the lateral forefoot region of right foot. All clubs, in impact, high force value observed in the lateral rarefoot region of left foot and medial forefoot region of right foot. Finish acting, force concentration observed on the rarefoot region in driver and lateral foot region in iron on left foot. 3. Right foot forces distribution were increased in address, back swing top and left foot force distribution were increased in impact, finnish

축구화 스터드의 형태변화에 따른 지면반력 분석

이중숙 한국운동역학회 2006 한국운동역학회지 Vol.16 No.1

녹차 및 결명자 추출물의 치주조직병 원인균에 대한 억제효과

이은숙,안태영,윤정중,국중기,이병래,김동기 대한구강보건학회 2003 大韓口腔保健學會誌 Vol.27 No.4

It is known that the periodontal disease is caused by infection of inner oral bacteria as a suffering disease to human mankind for a long time. It can make the various clinical symptoms such as gingiva, bleeding, formation of periodontal pocket, loss of attached gingiva, collapse of alveolar bone and halitosis, and is known to the major contributor of loss of teeth. This study investigated the growth restraint effect of Camellia sinensis and Casia tora. As a result of study, the minimum restraint concentration of standard microbe on F. nucleatum for extracts from C. sinensis showed 2.5, 0.63 and 1.25 mg/ml, respectively and minimum restraint concentration of clinical separation microbe on F. nucleatum for extracts from C. sinensis showed 2.5 and 5.0 mg/ml. The minimum restraint concentration of standard microbe and clinical separation microbe, respectively. Meanwhile, the minimum restraint concentration of standard microbe and clinical separation microbe on F. nucleatum for extracts from C. tora showed 2.5 and 2.5-5.0 mg/ml, respectively. The minimum restraint concentration of standard microbe and clinical separation microbe for P. intermedia, P. nigrescens, P. gingivalis, and P. endodontalis showed above 5.0 mg/ml for standard microbe and above 5.0 mg/ml for clinical separation microbe, respectively. As a result of investigating the cell toxicity for each extracts, extracts from C. sinensis does not showed the toxicity for the cell below the concentration of 2.5 mg/ml, but it showed toxicity for the cell above concentration of 2.5 mg/ml and it decreased the existence ratio for the cell. Meanwhile, in the case of C. tora, it increased the multiplication ratio below the concentration of 1.25 mg/ml compared to the subject group and it decreased gradually the multiplication ratio that the growth ratio for the cell is increased better than subject group. As a result of this study, extracts from C. sinensis was more effect on the growth restraint effect against periodontopathogens than extracts from C. tora and is proven that it is possible for use as a oral mouthrinsing liquids in the near future. On the basis of results of this study, it is judged that the study for reaction mechanism and discrete clinical test for implementation should be needed.

공기권총 사격동작의 생체역학적 분석

이중숙 한국운동역학회 1998 한국운동역학회지 Vol.8 No.2

In order to analyze elements of physical motions affecting air-gun shooting, this study has examined five right-hand shooters who have no physical handicaps on their arms and legs. Their shooting motions have been taped with two high-speed video cameras; GRF has been measured with two force platforms; and potential actions of arms have been examined with an EMG system. The examinations have brought out following results: 1. Results from Kinematics analysis. Since the air-gun shooting performs indoors, in the case that a shooter consumes more than 15 seconds from the ready position to the shooting moment, the oxygen level in the shooter body gradually drops, and it will bring negative effects on long-time shooting. Consequently, the time span from the ready position to the shooting moment should be minimized, and a shooter tries to keep a constant pace in shooting. The female air-gun shooting game usually takes about 90 minutes. The stance position may cause stress and fatigue. So, a shooter should try to maintain proper stance positions. In aiming motions, the abduct angle of the shoulder joint may vary according to shooters' height, but the angle should be minimized in shooting moment and a shooter should keep the angle steady throughout a whole game. 2. The GRF analysis. The air-gun shooting stance should be comfortable, natural, and steady. A shooter needs to keep his/her two feet apart at its shoulder width. If he/she felt comfortable in the stance, he/she should mark the foot positions. The shooter's weight has to be on the center of the stance, and the weight pivot in standing position must be right on the center of the floor stance. At the aiming moment, the moving motions of weight center should be minimized. 3. The EMG analysis The potential actions involved in the air-gun shooting motions may vary according to each related muscles. The related muscles from high tension to low are in the following sequence: deltoid, biceps brachii, brachoradialis, and flexor carpi radialis. Since this research shows the deltoid is the major muscle in shooting motions, strengthening the deltoid muscle is a key element for bettering the air-gun shooting. For the optimal result of air-gun shooting, the muscle relaxation exercise would be a major element to prevent the muscle spasm which could happen from the breathing motion to the triggering moment.

테니스 라켓 스트링 장력의 차이에 따른 근전도 분석

이훈식,서국웅,윤양진,정미라,김용재,서국은,이중숙 한국운동역학회 2000 한국운동역학회지 Vol.9 No.2

The purpose of this paper is to select 7 male athletes and female athletes of high school, and to compare their active potential differences of upper arm muscles according to characteristic of a racket. the results obtained are as follows: 1. In the accumulative distribution rate of racket string tension, 65Ibs is higher in all muscle active potentials except male flexor carpi radialis muscle than 55Ibs or 60Ibs, and this result shows that 65Ibs gives lower efficiency to athletes. 2. In the muscle load rate of racket string tension, 55Ibs shows the lowest active muscle potential and is thought to be better in its efficiency, but 66Ibs shows a little high active potential and is thought not to be good in its efficiency.

마그누스 효과의 스포츠 현장 활용 방안

이중숙 新羅大學校 1997 論文集 Vol.43 No.-

When players understand and effectively take advantage of the magnus effect in sports performances, they can achieve psychological calmness and confidence during their performances. Under the enormous mental pressure in sports game, players tend to practice rather passive game tactics in which they heavily depend upon defensive back-spin storkes. However, in order to get better results in top-class sports competition, players should achieve and various attacking capabilities understanding the dynamic principles of ball spinning. In this research, I analyzed how we can practically put the magnus effect into various ball-used sports performances which are roughly divided into the racket sports and ball sports The racket sports include tennis and ping pong; and the ball sports indicate soccer, basketball, and baseball. 1. In the racket sports, offensive-game-pattern players should perform more aggressive top-spin storkes than passive back-spin storkes. 2. In the racket sports, back-spin storkes can be effective at the hard court whose coefficient of friction is under 0.5. For example, when a player hits a ball at under 30 degree hitting angle with proper strength, the ball-bouncing angle becomes under 30 degree. 3. Performing services in the racket sports, right-left-side-spin stokes can be very effective offence because the side-spin ball can easily drive the opponent out of the court and make the opponent hard to return the ball. 4. In the racket sports, any kind of spinning ball becomes a top-spinning ball once after the ball has bounced. If a player understands the ball-spinning dynamics and predicts the ball direction, he can hit the ball easily attacking the opponent effectively. 5. In the ball sports, to disturb the predicting capabilities of the opponents, the change of pace in ball-spinning patterns is required. For example, even if a pitcher can throw a high-speed ball at 160km/h, the pitcher may face hard time in managing a game if the pitcher cannot use spin balls properly in change-of-pace pitching. 6. In the ball sports, in order to effectively attack change-of-pace balls of the opponent, a player must understand the magnus effect and carefully examine the motions of the opponent player. Consequently, we cannot easily decide what kind of spin ball is best. Each players must develop proper types of spin ball according to their performing capabilities and play patterns. With understanding the magnus effect, developing a player's predicting abilities about ball-spinning qualities and ball-moving directions will greatly improve the player's game-managing abilities.

테니스 서비스 동작의 운동역학적 분석

이중숙,이훈식 한국운동역학회 2000 한국운동역학회지 Vol.10 No.1

The purpose of this paper is to select 7 male athletes and female athletes of high school, and to compare their active potential differences of trunk muscle according to service motion of tennis. This paper also measures the duration time, and angular velocity of tennis service kinematic variations using Kwon3D(1993) program. When we generalize the change pattern of each variation through normalization process, the results obtained are as follows: 1. In the accumulative distribution rate of trunk muscles in service movement, male athletes show higher muscle active potential in the first service and female athletes show higher muscle active potential in the second service. 2. The ball speed of these athletes after an impact with the racket head is much slower compared with that of the world-famous athletes but of the proper flexsor and extensor of lower limbs, trunk, upper arm, forearm, and racket head are linked properly in sequence, biomechanical efficiency can be obtained in dong powerful service. 3. The angular velocity of wrist joint is much slower compared with that of the world-famous athletes, and this result is thought to be due to improper coordinated movement of the timing and rhythm in upper limb and trunk. 4. The great deviation of angular velocity in elbow joint among male athletes is due to the degree difference of using t he elbow joint. 5. The deviation of angular velocity in shoulder joint is also due to the improper coordinated movement and this keeps athletes from doing powerful service.

축구화 스터드의 형태변화에 따른 회전마찰력

이중숙,박상균 한국운동역학회 2004 한국운동역학회지 Vol.14 No.2

J. S. LEE, S. K. Park. Rotational Friction of Different Soccer Stud. Korean journal of Sport Biomechanics, Vol. 14, No. 2, pp. 121-138, 2004. The design of soccer studs is important for providing friction on a variety of surfaces. We hypothesized that a certain type of soccer studs could improve performance due to high rotational friction. Thus, this study was conducted to determine the relationship between the frictional characteristics and different soccer stud design. Twelve recreational soccer players were recruited. Rotational friction data from the force plate was collected for all subjects during normal walking with 180 degree rotation. Walking speed was controlled at 1.2 m/s (±0.1 m/s) with timing lights on infilled artificial turf. Three different types of soccer studs and one running shoe were tested. Repeated measures ANOVA was used to determine significance. Significant differences were found in rotational friction with four different shoes. Trx and World studs tended to have greater maximum rotational friction than the running shoe (Nova) and traditional soccer shoe(Copa Mondial). The results were as follow : world(25.95Nm) ) trx(25.74Nm) ) copa(22.50Nm) ) nova(16.36Nm). The difference may be due to the number, location, size, and shape of studs. We concluded that stud design influences rotational friction between the shoe and surface during movement. Based on studs design and contact area, Trx with blade type studs are recommended since it showed high rotational friction for performance as well as enough contact area for stability. However, differences due to the mechanical properties of soccer studs are still being investigated.

근전도 시스템을 이용한 테니스 퍼스트와 세컨드 서비스의 생체역학적 연구-남ㆍ여 고교 테니스선수를 중심으로 : 남ㆍ여 고교 테니스선수를 중심으로

이중숙,강재형,유창재,양정옥,이훈식 가톨릭대학교 자연과학연구소 2001 自然科學論文集 Vol.9 No.-

This study selected each seven high-school tennis players of male and female and analyzed the M.RA according to the type of tennis service and the Muscle Active Potential of M.ES by using an electromyogram system. The results as follows; 1.The Muscle Active Potential of female tennis players is higher than that of male tennis players in M.RA according to Tennis Service Types. 2.The Muscle Active Potential of female tennis players is higher than that of male players in M.ES according to Tennis Serrice Types. 3.In male and female M.RA, the Muscle Active Potential of right and left showed the contrary results. 4.In male and female M.ES, the Muscle Active Potential is high in the second service in the case of male and in the first service in the case of female. 5.Female tennis player can improve efficiency in the aspect of biomechanics by strengthening the muscle of M.RA and M.ES. 6.The second service of male tennis player showed less efficient Muscle Active Potential than his first service because of excessive trunk muscle twist.

중등학교 체육교육 현장의 실태 분석

이중숙 신라대학교 교육과학연구소 1999 교육과학연구 Vol.- No.4