한의 외래환자분류체계 개선 및 평가

류지선(Jiseon Ryu),임병묵(Byungmook Lim),이병욱(Byungwook Lee),김창훈(Changhoon Kim),한창호(Chang-ho Han) 대한한의학회 2014 대한한의학회지 Vol.35 No.3

달리기 시 속도 증감에 따른 지지국면에서 발 분절 움직임 분석

류지선 ( Ji Seon Ryu ) 한국운동역학회 2012 한국운동역학회지 Vol.22 No.1

The aim of the present study was to investigate effect of running speed conditions on the kinematic pattern of the metatarsus, mid-foot, calcaneus. Twenty-two healthy young adults were made to run on treadmill at three different running speeds (normal speed, 9.2; slow speed, 7.4; fast speed, 11.1km/hr.) and the trajectories of the 10 reflective markers for each subject were recorded by an eight-camera motion capture system at 200 Hz. Three-dimensional angles for the foot segment in the support phase during running were calculated according to Euler`s technique. Results showed that running speed did not affect the peak of the dorsi/plantar flexion, inversion/eversion, and adduction/abduction or their range of motion for each foot segment. However, when the running speed was fast, significant differences were found in the peak of the plantar flexion, eversion, and adduction and ROM (range of motion) of the dorsi/plantar flexion, inversion/eversion, and adduction/abduction between the foot segments, metatarsus, mid-foot, and calcaneus. It was proposed that the foot segment should be analyzed from a multi-segment system point of view on the basis of anatomical reference during locomotion.

태권도 품새 우수·비 우수선수 간 학다리서기의 균형성 비교

류지선 ( Ji Seon Ryu ),류시현 ( Si Hyun Yoo ),박상균 ( Sang Kyoon Park ),윤석훈 ( Suk Hoon Yoon ) 한국운동역학회 2012 한국운동역학회지 Vol.22 No.1

The purpose of this study was to investigate the balance differences between skilled players and less-skilled players during Hakdariseogi motion of Keumgang Poomsae in Taekwondo. To achieve the study goal, total of 10 Taekwondo athletes; 5 skilled players(S, body mass: 67.0±5.7 kg, height: 174.0±4.8 cm, age: 20.0±2.0 yrs) and 5 less-skilled players (LS, body mass: 73.0±4.9 kg, height: 176.4±6.1 cm, age: 20.8±1.3 yrs) participated in this study, A three-dimensional motion analysis with 8 infrared cameras and one force plate whose sampling frequency as 30 Hz and 300 Hz, respectively, were performed, Participants` motion were divided into three phases which were preparation phase (P1), performing phase (P2) and maintaining phase (P3). The range and velocities of COP, the range and RMS of ground reaction torque and displacement between COM and center of BOS of each phase were computed. In this study, at P1 and P3 which were double and single stance, respectively, the range and M-L velocities of COP revealed significantly higher in LS compared with those of S(p<.05). At P2 which was single stance, LS indicated significantly higher in range of COP and ground reaction torque, and M-L velocities of COP than those of S (p<.05). The significantly shorter displacement between COM and center of BOS, however, was found in LS compared with that of S (p<.05). The results from our study indicated that S revealed more stable performance and a better posture control ability during performing Hakdariseogi motion.

골프 드라이버 스윙 시 임팩트 전o후 신체 균형성이 클럽헤드의 속도와 각도에 미치는 영향

류지선 ( Ji Seon Ryu ),김태삼 ( Tae Sam Kim ) 한국운동역학회 2011 한국운동역학회지 Vol.21 No.4

The purpose of this investigation was to determine whether correlations exist between balance and impact velocity, angular position, and maximum velocity of a club during drive swing. Twelve skilled golfers were recruited in this study. They were asked to perform ten swing trials and two trials were selected for analysis. Balance parameters were calculated via the force platform while kinematic variables were determined by using the Qualisys system. The results of the present study demonstrated that the average of COP velocity was faster in the medio-lateral direction rather than the anterio-posterior direction. Also, left foot`s COP velocity and free torque were greater than the right foot`s before impact. The range of the right foot`s COP in the anterio-posterior direction before impact were correlated with the club velocity and angular position at impact. There was a negative correlation between the left foot`s COP velocity before the impact and the velocity at impact. Additionally, the range and RMS of the left foot`s free torque affected on the club angular position at impact and the maximum velocity at release, respectively. Finally, a negative correlation existed between the range of the right foot`s free torque after the impact and club`s maximum velocity at release.

2011 대구세계육상선수권대회 100m 남자 결승전 중간질주구간의 운동학적 분석

류지선 ( Ji Seon Ryu ),류재균 ( Jae Kyun Ryu ),김태삼 ( Tae Sam Kim ),박영진 ( Young Jin Park ),황원섭 ( Won Seob Hwang ),윤석훈 ( Suk Hoon Yoon ),박상균 ( Sang Kyoon Park ) 한국운동역학회 2011 한국운동역학회지 Vol.21 No.5

The purpose of this study was to provide scientific information to track and field coaches and athletes through the analyses of the biomechanics characteristics of the top 4 sprinters in the men`s 100 m final in the IAAF World Championships Daegu 2011. Twelve video cameras (Sony, Japan) were used to capture the mid portion of the race (40 m - 70 m) with a sampling frequency of 60Hz. Biomechanical variables including the right ankle, knee and hip angles, the trunk angle, and the velocity of center of mass (COM) in the running direction, were calculated with the Kwon 3D program (Visol, Korea). Correlation coefficients between the COM velocity and each variables were calculated using Matlab 2008a (MathWorks, USA) at an alpha level of 0.05. The findings indicated that Yohan Blake (JAM) showed greater range of motion at the ankle and hip. Walter Dix (USA) showed greater knee and trunk movement, and Kim Collins (SKN) showed more dorsi-flexed and extended trunk angles during the race. Finally, Christophe Lemaitre (FRA) showed more plantar-flexed ankle with a less trunk motion, throughout the analyzed race.

시뮬레이션을 통한 창던지기 거리 추정

류지선 ( Ji Seon Ryu ),이영선 ( Yong Sun Lee ) 한국체육대학교 체육과학연구소 2013 스포츠사이언스 Vol.31 No.1

본 연구는 실제 지도의 효율성과 훈련 처방의 효과성을 제공하기 위한 일환으로 남자 국가대표 창던지기 선수의 동작을 분석한 릴리즈 각과 공격 각, 창 각속도를 초기 조건으로 고려한 운동방정식을 구축한 시뮬레이션 기법에 의해 창던지기의 궁극적인 목적인 수평 거리를 추정하고자 했다. 그 결과 다음과 같은 결론을 얻었다. 실제 던진 수평 거리와 운동 방정식을 활용한 시뮬레이션 기법으로 추정한 수평 거리의 편차는 5.9%내에 있었다. 또한 시뮬레이션을 통한 수평거리 추정에 영향을 주는 변인은 초기 조건으로 설정된 릴리즈 각, 공격 각뿐만 아니라 투창 속도에 의해 좌우되었다. 실제 수평 거리를 가장 가깝게 추정한 시뮬레이션에서 릴리즈 속도가 상수로 간주할 때 릴리즈 각과 공격 각의 변화는 수평거리에 영향을 미쳤다. 따라서 선수들이 조절할 수 있는 릴리즈 각의 활용은 경기력 향상에 도움이 되리라 생각된다. The purpose of this study was to estimate the horizontal distance, finally aim of javelin, through a simulation which was set by motion equations that need release angle and attack angle at release for initial conditions. These initial conditions were used experimental data from a male javelin thrower of national team. In conclusions, There were within 5.9% of a deviation between a horizontal distance attained by a thrower and one estimated in a simulation technique. Intial conditions as well as release velocity which was regarded as constant in this simulation effected on the horizontal distances estimated in a simulation technique. When the release velocity set as a constant, the horizontal distance of simulation was as varied as release angle and attack angle. It accordingly suggested that release angle which was controlled by throwers themselves could used in performance.

편평족 달리기 시 충격 쇼크의 성분과 흡수

류지선 ( Ji Seon Ryu ),임가영 ( Ga Young Lim ) 한국운동역학회 2015 한국운동역학회지 Vol.25 No.3

Objective : The purpose of this study was to determine the differences in the head and tibial acceleration signal magnitudes, and their powers and shock attenuations between flat-footed and normal-footed running. Methods : Ten flat-footed and ten normal-footed subjects ran barefoot on a treadmill with a force plate at 3.22m/s averaged from their preferred running speed using heel-toe running pattern while the head and tibial acceleration in the vertical axis data was collected. The accelerometers were sampled at 2000 Hz and voltage was set at 100 mv, respectively. The peak magnitudes of the head and tibial acceleration signals in time domain were calculated. The power spectral density(PSD) of each signal in the frequency domain was also calculated. In addition to that, shock attenuation was calculated by a transfer function of the head PSD relative to the tibia PSD. A one-way analysis of variance was used to determine the difference in time and frequency domain acceleration variables between the flat-footed and normal-footed groups running. Results : Peaks of the head and tibial acceleration signals were significantly greater during flat-footed group running than normal-footed group running(p<.05). PSDs of the tibial acceleration signal in the lower and higher frequency range were significantly greater during flat-footed running(p<.05), but PSDs of the head acceleration signal were not statistically different between the two groups. Flat-footed group running resulted in significantly greater shock attenuation for the higher frequency ranges compared with normal-footed group running(p<.05). Conclusion : The difference in impact shock magnitude and frequency content between flat-footed and normal-footed group during running suggested that the body had different ability to control impact shock from acceleration. It might be conjectured that flat-footed running was more vulnerable to potential injury than normal-footed running from an impact shock point of view.

2011 대구세계육상선수권대회 100 m 여자 결승전의 운동학적 분석

류지선 ( Ji Seon Ryu ),류재균 ( Jae Kyun Ryu ),김태삼 ( Tae Sam Kim ),박영진 ( Young Jin Park ),황원섭 ( Won Seob Hwang ),윤석훈 ( Suk Hoon Yoon ),박상균 ( Sang Kyoon Park ) 한국운동역학회 2011 한국운동역학회지 Vol.21 No.5

The purpose of this study was to analyze the kinematic characteristics of the finalists in the women`s 100 m event to provide important information to coaches and athletes. Three different biomechanics techniques were applied for analyzing sprinter motion: LAVEG, a panning technique, and 12 video cameras for 3 dimensional analysis of the 40 m - 70 m portion of the race. Carmelita Jeter (USA) performed the maximum speed of 10.54 m/s at the distance of 58.2 m. There was a tendency to show a better performance time with a high number of steps (p=.13) and shorter stride length (p=.14) among the 8 sprints. Furthermore, the stride frequency and the performance time were negatively correlated as a higher stride frequency had a positive impact on the performance time (p=.02), Based on 3 dimensional analysis, the 4 top ranked sprinters used the different strategies to maintain a high COM (Center of Mass) velocity during the mid portion of the race (40 m - 70 m). Carmelita Jeter (USA) showed more flexed knee and hip motion at heel contact (HC) to maintain a high COM velocity while S.A. Fraser-Pryce (JAM) showed more extended knee and hip motion at HC. On the other hands, Veronica Campbell-Brown (JAM) and Kelly-Ann Baptiste (TRI) showed a tendency to have high knee lifts during the swing phase to maintain the high COM velocity during the race. These biomechanical analyses of the women`s 100 m final event in the 2011 WC, Daegu, will provide important scientific information to coaches and athletes for understanding the sprinting mechanism of today`s top-class sprinters.

오래달리기 시 시간 경과에 따른 지면 반력 성분의 Variability

류지선 ( Ji Seon Ryu ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.4

A study was conducted to investigate the possible effects of fatigue which was resulted from increased running time on the stability during a prolonged run. The purposes of this study were twofold: first, to determine the discrete and non-linear variability of GRF (ground reaction force) components between running times to know the body stability, and second, to determine the pattern between discrete and non-linear variability. Nineteens healthy young adult males served in this study as subjects who ran at their preferred running speed. GRF data for twenty strides were collected at 5, 65, and 125 minutes during run. Variance coefficient and Lyapunov Exponent techniques on the GRF data were used to calculate variability index for each of the running time conditions. There were no difference between discrete variabilities of three components of GRF, but non-linear variability of the Fz component of GRF was decreased by increasing running time (p<.01). No relationship was found between discrete and non-linear variability

스포츠산업과 운동역학 : 달리기 속도별 수직 지면반력 Passive portion 신호의 고역 필터링 전,후 선정된 성분 비교

류지선 ( Ji Seon Ryu ) 한국운동역학회 2005 한국운동역학회 추계학술발표논문집 Vol.2005 No.-