• 한국운동역학회지
• /
• 제20권4호
• /
• pp.429-436
• /
• 2010

The purpose of this study was to analyze the kinematic factors and throwing variables for the 3-turn and 4-turn techniques and for release as well as to provide technical advice for improving athletic performance in hammer throwing. Data analysis led to the following conclusions: To increase the rotation speed for the 3-turn and 4-turn techniques, the time elapsed during the 1-foot support period should be decreased the distance between the rotating foot and the rotation axis should be small and the height of the hip joint should be increased at the times of release The throwing angle at the moment of release should be more than 40 degrees, and the throwing position should be taken vertically high at the shoulder joints. To accelerate the motion of the hammer, the speed should not be reduced during the 1-foot support period but should be increased during the 2-foot support period for much greater acceleration. In the 3-turn technique, the angles of the shoulder axis and hummer string should be dragged angle at the maximum point and lead angle at the minimum point, and dragged angle at the maximum and minimum points in the 4-turn at the time of relase The upper body should be quickly bent backward, the knee angle should be extended, and the angles of the shoulder axis and hammer string should be dragged angle close to 90 degrees.

• 한국운동역학회지
• /
• 제23권3호
• /
• pp.209-218
• /
• 2013

This study was to perform the kinetic analysis of forward $1\frac{1}{2}$ somersault on the platform diving. Six men's diving players of the Korea national reserve athletes participated in this study. The variables were analyzed response time, velocity, center of mass (COM), angle, center of pressure (COP) and ground reaction force (GRF) of motion. For measure and analysis of this study, used to synchronized to 4 camcorder and 1 force plate, used to the Kwon3D XP (Ver. 4.0, Visol, Korea) and Kwon GRF (Ver. 2.0, Visol, Korea) for analyzed of variables. The results were as follows; Time factor were observed in maximum knee flexion depending on the extent of use at phase 1 of take-off to execute the somersault. This enabled the subject to secure the highest possible body position in space at the moment of jumping to execute the somersault and prepare for the entry into the water with more ease. Regarding the displacement of COM, all subjects showed rightward movement in the lateral displacement during technical execution. Changes in forward and downward movements were observed in the horizontal and vertical displacements, respectively. In terms of angular shift, the shoulder joint angle tended to decrease on average, and the elbow joints showed gradually increasing angles. This finding can be explained by the shift of the coordinate points of body segments around the rotational axis in order to execute the half-bending movement that can be implemented by pulling the lower limb segments toward the trunk using the upper limb segments. The hip joint angles gradually decreased; this accelerated the rotational movement by narrowing the distance to the trunk. Movement-specific shifts in the COP occurred in the front of and vertical directions. Regarding the changes in GRF, which is influenced by the strong compressive load exerted by the supporting feet, efficient aerial movements were executed through a vertical jump, with no energy lost to the lateral GRF.

• 치위생과학회지
• /
• 제12권4호
• /
• pp.437-442
• /
• 2012

이 연구는 20명의 치위생과 학생들을 대상으로 스켈링 실습 시 발현되는 근육들의 활성도와 통증부위를 파악하여 치과위생사의 작업자세에 따른 기초자료를 제시하고자 연구를 실시하였다. 스켈링 시 근활성도의 측정은 free EMG를 이용하였고, 근골격계 통증부위를 알아보기 위해 Nordicstyle 설문지를 이용하여 측정된 연구결과는 다음과 같다. 1. 자세에 따른 스켈링 시 통증의 발현은 팔꿈치, 등, 다리, 무릎, 발목/발은 그룹간에 차이가 없는 것으로 나타났으나 목, 어깨, 손목/손, 허리에서는 자세에 따라 통증의 정도 차이가 높게 나타났다. 2. 자세에 따른 근활성도를 측정한 결과 올바른 자세를 가진 그룹에서는 시간의 경과에 따라 상승모근과 상완요골근에서 변화를 보였고, 나쁜 자세를 가진 그룹에서는 후두부근, 상승모근, 상완요골근에서 근활성도가 높게 나타났다. 3. 근활성도에서 두 군간의 변화양상은 좋은 자세로 스켈링을 실시한 그룹에서는 낮은 근활성도를 보였으나, 나쁜자세로 스켈링을 실시한 그룹에서는 근활성도가 과하게 증가되었다. 따라서 올바른 자세를 유지하며 스켈링을 실시하는 것이 근육의 활성을 효과적으로 사용하는데 도움이 되었음을 알수 있었고, 앞으로 임상에서 근무하는 치과위생사를 대상으로 연구를 실시하여 직무 효율성을 높이는 것이 필요하리라 생각된다.

• 한국운동역학회지
• /
• 제17권2호
• /
• pp.177-185
• /
• 2007

Even though there were no clear definitions of the short game and short game distance, short game capability is crucial for a good golf score. Generally, chip shot and pitch shot are regarded as two principal components of the short game. Chip shot is a short, low trajectory shot played to the green or from trouble back into play. Pitch shot is a high trajectory shot of short length. Biomechanical studies were conducted usually to analyze full swing and putting motions. The purpose of the study was to reveal the kinematical differences between professional golfers' 30 yard $53^{\circ}wedge$ chip shot and $56^{\circ}wedge$ pitch shot motions. Fifteen male professional golfers were recruited for the study. Kinematical data were collected by the 60 Hz three-dimensional motion analysis system. Statistical comparisons were made by paired t-test, ANOVA, and Duncan of the SPSS 12.0K with the $\alpha$ value of .05. Results show that both the left hand and the ball were placed left of the center of the left and right foot at address. The left hand position of the chip shot was significantly left side of that of the pitch shot. But the ball position of the pitch shot was significantly right side of that of the chip shot. All body segments aligned to the left of the target line, open, at address. Except shoulder, there were no significant pelvis, knee, and feet alignment differences between chip shot and pitch shot. These differences at address seem for the ball height control. Pitch shot swing motions(the shoulder and pelvis rotation and the club head travel distance) were significantly bigger than those of the chip shot. Club head velocity of the pitch shot was significantly faster than that of the chip shot at the moment of impact. This was for the same shot length control with different lofted clubs. Swing motion differences seem mainly caused by the same shot length control with different ball height control.

• 한국운동역학회지
• /
• 제14권2호
• /
• pp.27-40
• /
• 2004

The objective of this study is to identify the kinematic variables of giant swing backward to handstand as well as individual variations of each athlete performing this skill, which in turn will provide the basis for developing suitable training methods and for improving athlete's performance in actual games. For this end, 3 male athletes, members of the national team, who are in ${\Box}{\Box}H{\Box}{\Box}$ University, have been randomly chosen and their giant swing backward to handstand performance was recorded using two digital cameras and analyzed in 3 dimensional graphics. This study came to the following conclusion. 1. Proper time allocation for giant swing backward to handstand are: Phase 1 should provide enough time to attain energy for swing track of a grand round movement. The phase 3 is to throw the body up high in the air and stay in the air as long as possible to smoothen up the transition to the next stage and the phase 4 should be kept short with the moment arm coefficient of the body reduced. 2. As for appropriate changes of locations of body center, the phase 1 should be comprised of horizontal, perpendicular, compositional to make up a big rotational radius. Up to the Phase 3 the changes of displacements of vertical locations should be a good scale and athlete's body should go up high quickly to increase the perpendicular climbing power 3. When it comes to the speed changes of body center, the vertical and horizontal speed should be spurred by the reaction of the body in Phase 2 and Phase 3. In the Phase 4, fast vertical speed throws the body center up high to ensure enough time for in-the-air movement. 4. The changes of angles of body center are: in Phase 2, shoulder joint is stretching and coxa should be curved up to utilize the body reaction. In the Phase 4, shoulder joint and coxa should be stretched out to get the body center as high as possible in the air for stable landing. 5. The speeds of changes in joints angles are: in the Phase 2 should have the speed of angles of shoulder joints increase to get the body up in the air as quickly as possible. The Phase 3 should have the speed of angles in shoulder joint slow down, while putting the angles of a knee joint up to speed as quickly as possible to ensure enough time for in-the-air movement.

• 대한정형외과스포츠의학회지
• /
• 제3권1호
• /
• pp.66-72
• /
• 2004

목적: 후방 십자 인대 손상 환자의 포괄적 기능적 검사를 시행한 후 동일 조건의 정상인과 비교 분석함으로써 생체 내의 보상기전을 알아보고 향후 치료에 유용한 지침을 개발하는데 있다. 연구대상 및 방법: 10명의 후방 십자 인대 손상 환자와 10명의 정상 대조군을 대상으로 운동 범위, 후방 전위 검사, KT-1000을 이용한 후방 전위 검사, 텔로스 스트레스 및 30도 굴곡 전 체중 부하 방사선 검사, 보행 분석, 근전도 검사, 등 운동성 근력 검사 등을 시행하였다. 결과: 이학적, KT-1000, 텔로스 후방 전위 검사에서는 양군 간에 의미 있는 차이를 보였으나 30도 굴곡 전 체중 부하 방사선검사, 굴곡 및 신전건의 근력 검사에서는 차이가 없었다. 보행 시 후방십자인대 결손 군은 초기 착지 시 슬관절 굴곡을 더 적게 하고 입각기 시 슬관절 최대 외반 관성력은 감소하였다(p=0.027). 수직 착지 시 초기 접촉이 일어나는 순간 더 큰 족저 굴곡을 보이므로(p=0.014) 슬관절의 하중 부담을 감소시켰고(p=0.020) 근전도 검사 및 근력에서는 유의한 차이가 없었다. 결론: 후방 십자 인대 손상 후 환자들은 슬관절의 불안정 요소를 줄이고 충격을 최대로 흡수하는 보상 작용을 수행하여 훌륭한 임상적, 기능적 결과를 나타내며 향후 지속적인 연구가 필요하다.

• 한국체육학회지인문사회과학편
• /
• 제55권2호
• /
• pp.643-655
• /
• 2016

본 연구는 내리막 경사의 변화에 따른 노인집단과 젊은 성인집단의 운동역학적 보행분석을 통해, 두 집단 간 보행패턴의 차이를 비교 분석하여 노인들의 운동역학적 측면에서 낙상 요소를 파악하는데 목적이 있다. 20대 건강한 젊은 성인여성집단(yrs: 21.17±1.5)과 65세 이상의 건강한 노인여성집단(yrs: 66.67±1.33)을 대상으로 각각 18명씩 실험 참여자로 선정하였으며 트레드밀 위에서 선호속도로 평지, -7.5°, -15°의 세 가지의 경사조건에서 보행을 실시하였다. 노인집단은 성인집단에 비해 내리막 보행 시 신체중심의 좌우변위가 더 큰 것으로 나타났고(p<.05), 경사에 따라 무릎과 발목 관절의 발목 가동변위는 노인집단이 더 작은 것으로 나타났다(p<.05). 엉덩관절의 가동범위에서는 집단 간 차이가 나지 않았지만 노인집단의 최대 신전 각은 성인집단보다 작은 것으로 나타났다(p<.05). 또한, 내리막 보행 시, 성인집단보다 더 적은 무릎 신전모멘트가 작용한 것으로 나타났다(p<.05). 본 연구 결과 노인들은 내리막 보행 시 낙상 위험에 더욱 노출되고 불안정한 보행을 할 것이라는 예상과 달리 젊은 성인집단보다 더욱 안정적인 보행 전략을 세워서 걷는 것으로 나타났다. 본 연구를 통해 노인들의 보행특성 및 낙상과 관련된 운동역학적 변인을 수집하고, 노인의 낙상을 예방하기 위한 후속연구의 기초자료로서 도움을 줄 것이라 예상된다.

• 한국운동역학회지
• /
• 제15권1호
• /
• pp.29-44
• /
• 2005

The purpose of this study is to reveal the effects of two different kicks, the drop kick and the punt kick, into the kicking motion, through the kinetic comparative analysis of the kicking motion, which is conducted when one kicks a soccer goal. To grasp kinetic changing factors, which is performed by individual's each body segment, I connected kicking motions, which were analyzed by a two dimension co-ordination, into the personal computer to concrete the digits of it and smoothed by 10Hz. Using the smoothed data, I found a needed kinematical data by inputting an analytical program into the computer. The result of comparative analysis of two kicking motions can be summarized as below. 1. There was not a big difference between the time of the loading phase and the time of the swing phase, which can affect the exact impact and the angle of balls aviation direction. 2. The two kicks were not affected the timing and the velocity of the kicking leg's segment. 3. In the goal kick motion, the maximum velocity timing of the kicking leg's lower segment showed the following orders: the thigh(-0.06sec), the lower leg(-0.05sec), the foot(-0.018sec) in the drop kick, and the thigh(-0.06sec), the lower leg(-0.05sec), the foot(-0.015sec) in the punt kick. It showed that whipping motion increases the velocity of the foot at the time of impact. 4. At the time of impact, there was not a significant difference in the supporting leg's knee and ankle. When one does the punt kick, the subject spreads out his hip joint more at the time of impact. 5. When the impact performed, kicking leg's every segment was similar. Because the height of the ball is higher in the punt kick than in the drop kick, the subject has to stretch the knees more when he kicks a ball, so there is a significant affect on the angle and the distance of the ball's flying. 6. When one performs the drop kick, the stride is 0.02m shorter than the punt kick, and the ratio of height of the drop kick is 0.05 smaller than the punt kick. This difference greatly affects the center of the ball, the supporting leg's location, and the location of the center of gravity with the center of the ball at the time of impact. 7. Right before the moment of the impact, the center of gravity was located from the center of the ball, the height of the drop kick was 0.67m ratio of height was 0.37, and the height of the punt kick was 0.65m ratio of height was 0.36. The drop kick was located more to the back 0.21m ratio of height was 0.12, the punt kick was located more to the back 0.28m ratio of height was 0.16. 8. There was not a significant difference in the absolute angle of incidence and the maximum distance, but the absolute velocity of incidence showed a significant difference. This difference is caused from that whether players have the time to perform of not; the drop kick is used when the players have time to perform, and punt kick is used when the players launch a shifting attack. 9. The surface reaction force of the supporting leg had some relation with the approaching angle. Vertical reaction force (Fz) showed some differences in the two movements(p<0.05). The maximum force of the right and left surface reaction force (Fx) didn't have much differences (p<0.05), but it showed the tendency that the maximum force occurs before the peak force of the front and back surface (Fy) occurs.