남자 대학 세단뛰기 선수들의 도움닫기 마지막 3스트라이드의 유형과 접지와 이지 순간의 운동학적 분석

류재균,장재관,김상도 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

The purposes of this study were to examine the characteristics of the kinematic factors of the final three strides before takeoff of a triple jump and to collect the fundamental quantities of motion in order to improve the triple jump performance. The subjects were the 5 Finalists For an actual 16.70m over in the triple jump at the 2003 World Student Games. The last three strides were analysed using three cameras, The x, y, z coordinates of 20 points defining a Fourteen segment model of the human body were used For Further analysis, After smoothing the raw data with a fourth order Butterworth Filter, the centres of gravity of the subjects were calculated. After analyzing the kinematic data during the final three strides, the following findings were obtained: The last three stride Length changes in triple jump did not have a consistent pattern and showed the varieties in jumpers' technical preference. The height of center gravity was different in each event of the last three strides but the lowest center of gravity was the time of touchdown on the board. The maximum horizontal velocity was shown at the second-last and third-last stride takeoff instances.

Kinematical Aspects Gliding Technique in 500-m Speed Skaters: From Start to Seven Strokes

류재균,김영숙,홍성홍 한국운동역학회 2016 한국운동역학회지 Vol.26 No.4

Objective: The purpose of this study was to assess the consistency of the gliding and push-off motion for single leg skating from the first to fourteenth steps. We hypothesized that: 1) there would be no difference in stroke trajectory, step rate, and cycle rate between the left and right steps of gliding; and 2) there would be a difference in the resultant velocity of toe push-off and the horizontal velocity of the center of mass after six step push-offs. Method: The study included five male 500-m speed skaters (mean height, 1.80 ± 0.02 m; mean weight, 76.8 ± 3.96 kg; record, 35.83 ± 0.30 sec; 100-m record, <9.97 sec). Data were collected from the first to fourteenth steps (40 m) and recorded using five digital JVC GR-HD1KR video cameras (Victor Co., Japan) operating at a sampling frequency of 60 fields/sec and shutter speed of 1/500 sec. For each film frame, the joint positions were digitized using the KWON3D motion analyzer. Position data were filtered with low-pass Butterworth 4th order at the cut-off frequency of 7.4 Hz. Results: The right toe of the skating trajectories at 2nd, 5th, and 7th strokes differed from those of the left toe. The angles of the right and left knee demonstrated unbalanced patterns from the flexion and extension legs. The step and cycle rates of the right and left leg differed from the start until 20 m. The resultant velocities of the toe at the push-off phase and of the body mass center diverged before the six push-offs. Conclusion: This study's findings indicate that the toe of skating trajectory on left and right sliding after push-off should maintain a symmetrical trajectory. The resultant velocity of toe push-off and horizontal velocity from the center of body need to be separated after about six step push-offs.

세단뛰기 지지국면 시 사지의 각운동량과 운동수행과의 관계

류재균,여홍철 한국운동역학회 2004 한국운동역학회지 Vol.14 No.1

J. K. RYU, H. C. YEO. The Relationship between the Angular Momentum of the Limbs and the Performance during Support Phase of the Triple Jump. Korean Journal of Sport Biomechanics, Vol. 14, No. 1, pp. 65-81, 2004. The purposes of this study were to determine the functions of actions of the limbs during each of the three support phases of the triple jump and their relationships with the performance of the triple jump. Four elite male triple jumpers were participated as subjects. The Pearson product moment correlation coefficient were used to determine and compare the relationships between the change in each component of the normalized angular momentum of the whole body about center of gravity and the actions of the extremities during different support phases. A level of significance at a=.05 was set. After analyzing the angular momentum and correlation during support phase of the hop, step, and jump, the following findings are obtained: The actions of the arms created a side-somersaulting angular momentum about the whole body center of gravity toward the side of the free leg during the support phase of the step, and a somersaulting angular momentum about the whole body center of gravity during each support phase. The action of the free leg created a somersaulting angular momentum about the whole body center of gravity during the support phases of the hop and step.

국외 8m 이상 멀리뛰기 선수와 국내 선수들의 운동학적 비교 분석

류재균 한국운동역학회 2005 한국운동역학회지 Vol.15 No.3

세단뛰기 지지국면 시 사지의 운동학적 변인과 전신 무게중심의 속도 변화와의 관계

류재균,정철정,박진 한국운동역학회 2003 한국운동역학회지 Vol.13 No.3

세단뛰기 흡 구간에 관한 운동학적 분석

류재균,김창환,김혜영 한국운동역학회 2000 한국운동역학회지 Vol.9 No.2

The aims of this study were to examine the effects of the kinematic factors of the hop distance during the hop phase of a triple jump, and to help the improvement to the officially recorded distance of the triple jump. Two-dimensional kinematic data were collected for three elite male triple jumpers. Hop distance, support time, flight time, changes in the velocity of the whole body center of gravity and changes in the horizontal and in the vertical velocity at the takeoff were determined for the hop performance. The results of the measured and observed hop distances showed that the error in the coordinate was generally less than 0.01m. The results of the support time showed that there was to examine 0.13s. The results of the flight time showed that there was to examine 0.53s. The results of the velocity of the whole body center of gravity showed that the horizontal velocity was to examine about 9.6m/s before takeoff for hop and about 8.3m/s after takeoff for hop, respectively. Linear regression analysis was conducted to examine the relationship between loss in horizontal velocity and gain in vertical velocity. The loss in horizontal velocity increased as the gain in vertical velocity increased. The loss in horizontal velocity was found to be a linear function of the gain in vertical velocity. These results support to determine the hop distance of this study, Further studies are required on the optimum techniques of the triple jump.

멀리뛰기 8m 선수들의 운동학적 변인 조사를 통한 국내 멀리뛰기 선수들의 8m 뛰기 전략

류재균 한국운동역학회 2005 한국운동역학회지 Vol.15 No.2

골프스윙 축의 운동에 관한 고찰

류재균,장재관 한국스포츠리서치 2006 한국 스포츠 리서치 Vol.17 No.4

세단뛰기의 운동학적 운동역학적 분석

류재균 한국스포츠리서치 2006 한국 스포츠 리서치 Vol.17 No.4

자연과학편 : 110m 허들 선수들의 4-5허들 인터벌구간의 세 스트라이드 동작에 대한 운동학적 분석

류재균(JaeKyunRyu),이정호(JungHoLee),김혜영(HyeYoungKim) 한국체육학회 2006 한국체육학회지 Vol.45 No.5

이 연구의 목적은 4번째와 5번째 허들의 인터벌구간에서 세 스트라이드에 대한 선수 개개인의 기술을 분석하여 코치와 선수들에게 보폭과 보율의 정량적인 자료를 제공하는 것이다. 세 명의 선수들 모두 최선을 다해 달려 허들을 넘었고 비디오 자료는 4대의 JVC 비디오카메라를 이용하여 수집하였다. 촬영범위는 가로 18m 높이 2m 그리고 세로 1m이며 출발 라인으로부터 45m 지점을 촬영의 중심점으로 설정하였다. 운동학적 자료를 얻기 위해 인체는 14개의 분절을 연결된 강체계로 모델링하였다. 속도, 보폭, 보율 그리고 신체의 기울기 각을 산출하였다. 이 연구에서 C선수는 피치 빈도(보율)가 2스트라이드에서 3.53 sec^-1, 3스트라이드에서 4.61 sec^-1로 증가하였다. A와 B선수의 신체중심의 수평속도는 허들 착지 후 감속하였다가 1보에서 3보로 진행됨에 따라 증가하였다. 세 선수 모두 지지시간과 소요시간은 인터벌 구간에서 유사하게 나타났다. 연구 결과 허들 사이에서 보율을 높이고 3스트라이드에서 수직속도를 줄인다면 인터벌 구간에서 달리는 수평속도를 증가시킬 수 있을 것이다. The purpose of this study was to analyze individual techniques among athletes and provide scientific data to coaches and athletes by finding relative influence of the determinants of step length and rate. The video data were collected by using 4 JVC video cameras. The video capture volume was 18meters long, 2meters high and 1meter wide and was centered 45meters from the sprint start line. The human body was modeled as 14 rigid segments articulating at joints with fixed centers of rotation. Sprint velocity, step length, step rate and body tilting angle were calculated. This study showed that A, B, and C athletes recorded 1.41meters, 1.38meters, and 1.51meters respectively in first stride. C athlete showed increased frequency from 3.53 sec^-1 to 4.61 sec^-1. Horizontal velocities of center of mass in A and B athletes were reduced after landing from hurdles but the velocities were increased between first and third step. All athletes had similar supporting and spending time between hurdles. In conclusion, the high step rate between hurdles and the minimized vertical velocity in last third stride were required in order to improve horizontal velocity.