자연과학편 : 3D 영상분석에 의한 테니스 풀랫 서브의 운동학적 분석

황인승(InSeongHwang),이성철(SungCheolLee),김주선(JooSunKim) 한국체육학회 1992 한국체육학회지 Vol.31 No.2

The purpose of this study was to analyze the kinematic factors of tennis serve technique by using 3 dimensional cinematographic analysis and to provide basic guidelines for coaching. Two high speed cameras were used to analyze 5 beginners and 4 amateur players’ tennis serve. The conclusions of this study were following as:1. In the comparison of serve time between the amateur and beginner group, amateur group(1.28s) spend more time than the beginner group(1.10s) in the preparatory phase. But amateur group (0.13s) spend less time compared to beginner group (0.17s) in the force production phase.2. In the prerparatory phase, the range of C.O.G displacement in amateur group was bigger than beginner group in X, Y, Z; direction. In the force production phase, the beginner group showed bigger change than. the amateur group.3. In the force production phase, the amateur group did trunk rotation bigger than beginner group in X, Y. Z direction and flat serve was effective in longitudinal axis.4. The knee joint of amateur group was bigger than the beginner group at the impact.5. In the force production phase. the linear velocity of each segment increased as it moved toward distal segment. The maximum linear velocity occured before the impact and decreased at the impact. In the maximum linear velocity of racket. amateur(20.78m/s) group was faster than the beginner(18.62m/s) group.

자연과학편 : 고속 카메라의 panning 기술을 적용한 운동 동작 분석법의 개발

황인승(InSeongHwang),이성철(SungCheolLee),이기태(KiTaeLee) 한국체육학회 1989 한국체육학회지 Vol.28 No.1

Background markers and control points were filmed through the panning technique by a Photosonic high-speed camera with zoom lens. The x, y coordinates of each control of point were measured. The given x, y coordinates and computed x, y coordinates which were obtained through talc computer program written for this study were compared.Absolute mean errors far x and y coordinates were 1.376cm and 0.957cm respectively.The percentage of these errors were respectively 0.31% and 1.28%As the results, it was concluded that the panning technique and calculation used in this study were acceptable and could be applied to human movement studies.

운동역학 : 태권도 돌려차기시 근활동 모양에 관한 3차원적 분석

황인승(InSeongHwang),이성철(CheolSungLee) 한국체육학회 1999 한국체육학회지 Vol.38 No.1

8명의 태권도 선수들의 돌려차기 기술을 3차원 영상분석법을 이용하여 좌표화 하였다. 차는 다리의 3차원 모델을 만든 후 Cardan 각과 Euler`s 함수를 이용하여 각 관절의 해부학적 각운동과 토크를 구한 후 각 분절에서의 근활동 양상과 상호관계를 알아보았다. 일반적으로 생각하듯 개개분절들의 동작방향의 근군들만이 작용하는 것이 아니라 동작초반에는 동작방향의 근군이 약하게 작용하고 동작후반에는 오히려 동작 반대방향의 근군들이 특히 이심성수축으로 많은 부분 작용하는 것으로 나타났다. 이러한 현상은 말초분절로 갈수록 더욱 분명하게 나타났고, 이것으로 미루어 볼 때 최고 기시분절인 몸통운동이 나머지 다리분절들의 운동을 가동시키고, 다리분절 내의 각 관절에서의 근활동은 단지 가동보다는 조절 역할을 하는 것으로 보여졌다. The roundhouse kicks in taekwondo of eight high school players were filmed using the Direct Linear Transformation method of three-dimensional cinematography. Obtained coordinate data and the model developed using Cardan angles and Euler`s Equation were used to calculate the joint torques exerted on the kicking leg segments(the thigh, the shank and the foot).The Cardan angles between the two embedded axes of the two connected segments was used to define the anatomical motions of the segments. The anatomical motions and the joint torques of the segments were analyzed to determine the net muscle activity pattern. The findings indicated that the eccentric activities of the antagonists were primarily responsible for this kick movement. Such antagonists activities were more apparent on the shank than that on the thigh.Based on these finding, it can be tell that the muscle activities of the proximal segments activate the movement by the agonist at the beginning stage while the muscle activities of the distal segments control the movement by antagonist except the joints which have small range of motion or stiff joints like ankle.So the coaches have to emphasize the movement of the prime proximal segment, trunk, which activate this kicking movement and the control of the remained segments can be achieved naturally by the repeated training.

자연과학편 : 투사거리에 따른 농구 점프 슛 동작의 운동학적 분석

최지영(JiYoungChoi),황인승(InSeongHwang),이성철(SungCheolLee) 한국체육학회 1992 한국체육학회지 Vol.31 No.2

The purpose of this study is to suggest mechanical variables of successful 3-point jump-shot movement by identifying variations of jump-shot movement patterns accompanying horizontal distance variables.Five male basketball players of Yonsei University were filmed on a 16mm Photosonic 1PL High Speed Camera performing jump-shot movements accompanying projection distance. A spatial peformance point, four points on basketball and 17 two-dimensional X. Y coordinates of body segment anatomical marks were used as input in a movement analyzing-computer program and then. smoothed with cutoff frequency set at 7㎐ to obtain kinematic data needed for movement analysis. After comparing and analyzing kinematic data, the following results were obtained through the statistical analysis process.1. In the shooting phase, that affects projection angle and projection velocity, the short duration variable was obtained in the 3-point shot movement, and horizontal displacement distance in airborne phase in 3-point shot movement indicates that the horizontal displacement distance moved more(26㎝) toward the target relative to the 2-point shot.2. During projection, center of gravity displacement is almost the same. But, on the other hand, maximum displacement occurs 0.13sec after in the 2-point shot and 0.18sec after in the 3-point shot movement. This indicates that the projection movement occurs before arriving at the maximum point.3. In each arm segment, at the moment of jump and projection. X axis direction velocity variable between two movements show significant difference Especially X axis direction velocity variable of the 3-point shot movement in hand segment at the moment of jump and projection were high. Also, in the case of the 3-point shot movement from the moment of jump to pojection X axis direction velocity variable of the hard joint shows a sudden increase.4. At the height of projection there are no significant differences between the two movements but. angle of projection in the 3-point shot movement is small, and projection velocity in the 3-point shot movement shows a significant increase.In conclusion. since the 3-point jump shot movement needs additional momentum relative to the 2-point shot, that has short. horizontal distance variable, by shortening the duration variable in shooting phase, the shooting movement from a far distance can successfully be performed through transition of momentum, developed at the moment of jump, to the basketball quickly and powerfully. Especially, by additionally increasing each body segment`s velocity variable of X axis direction during the jump and projection. can overcome horizontal distance variable that acts on 3-point shot movement, and a successful projection movement can be performed. Also, in an effort to adopt additional horizontal direction momentum, that is developed in each body segment accompanying horizontal distance variable held farther apart, to the basketball, decrease in projection angle and increase in projection angle were discovered.

자연과학편 : 태권도 앞차기의 운동학적 분석

백일영(IlYoungPaik),장기준(KiJunChang),황인승(InSeongHwang) 한국체육학회 1986 한국체육학회지 Vol.25 No.2

The kinematic variables of Apchagi in Taekwondo were analized. The Apchagi variables compared in two situations ;1) When the subjects performed the tickings with target.2) When the subjects performed the tickings without target.Three Taekwondon athletes who hare practiced for more than seven yearn were selected among Yonsei University Taekwondo team as SubjectsThe hip, knee, ankle and metatarsal phalangat joints of the subjects were marked with white dots.The kicking performances were filmed using Bolex high speed camera with film speed of 64 frames / sec.The velocity, acceleration, angular velocity and angular acceleration If the necessary joints and segments were calculated through kinematic analysis procedure Which developed in Yonsei University.The results reported in graph form to provie basic information for the skills and compared the kinematic variables of the two kicking, with target which simulate competitive situation and without target which is used for training, to provide information fur training.The following conclusions could draw from the results.The patterns of the kinematic variables of the kicking with target and without target were similar, however the patterns in relate with the target area were which suggest prectie kicking should perform with soft target, different as if the whole pattern shifted backward and showed low values at the target area in kicking without target. The angular velocity of the thigh decreased as the velocity of the shank increased and showed whipping motion which is most efficient mechanical method to increase velocity of the distal segment.