농구경기 리바운드 점프 후 착지 시 시각차단과 볼 위치에 따른 지면반력 비교분석

류재청 ( Che Cheong Ryew ),현승현 ( Seung Hyun Hyun ) 제주대학교 해양스포츠센터 2014 해양스포츠연구 Vol.4 No.1

The purpose of this study was to analyse the GRF according to the visual informations blockage and ball positions during basket ball rebound jump. To achieve the study goal, Total 5 healthy adults male(age: 20±0.00yrs height: 173.10±1.58cm, weight: 60.05±3.89kg) participated in this study. A force-plate was used to collect GRF (AMTI-OR-7) data at a sampling rate of 1000Hz/sec. The GRF variables analyzed were consisted of the medial-lateral GRF, anterior-posterior GRF, vertical GRF and loading rate during landing. The medial-lateral GRE, anterior-posterior GRE and vertical GRF didn`t show significant difference statistically according to the visual informations blockage and bail positions but ball trajectory on head showed the higher anterior-posterior of GRF than that of the chest position of ball during landing. Also, visual informations blockage showed the higher vertical of GRF than that of the visual informations during landing. Also the visual informations blockage showed significant difference statistically of the higher than that of visual informations in loading rate during landing.

20대 여성의 체중과 힐 높이에 따른 보행자세의 운동역학적 비교분석

류재청(Che Cheong Ryew),현승현(Seung Hyun Hyun) 한국사회체육학회 2013 한국사회체육학회지 Vol.0 No.51

This purpose of this study was to analyse the kinetic comparison of the gait pattern according to body weights and shoe`s heel heights in the 20`s age women. Participants were selected 15 young and healthy women and were divided into 3 group(lean n=5, normal n=5, obese n=5) and walked with 3 shoe`s highheeled shoe`s(0 cm, 6 cm, 9 cm). The elapsed time, COG displace ment and ground reaction force(GRF) according to the gait pattern were compared with body weights and shoe`s heeled by using two way repeated ANOVA(p< .05). The results of the above were as follows; 1. According t o shoe`s heel heights and body weights, the elapsed time by phases showed shorter in TS than that of LR. 2. The COG displacement in X-axis showed the longer movement according to increase of body weight, but showed the less movement according to increase of heel height. 3. GRF in anterior-posterior(Fy) and vertical(Fz) axis showed the larger reaction force according to heel heights and body weights.

수중관광 및 학습장을 위한 레저스포츠 포인트 개발을 위한 타당성 연구

류재청(Ryew Che-Cheong) 한국체육과학회 2001 한국체육과학회지 Vol.10 No.1

The survey was undertaken to suggest validation of underwater leisure tourism point development of Eu-Yeng coast line of Jeju city after comprasion in economic level, quality of underwater scene, distribution of underwater animal & plants, underwater geographic figure, safety, a number of visitors through a year with other points of Jejudo. On the basis of survey conclusions obtained was to be based on 「aviation-ocean-mid mountain」 on each air leisure sport-golf leisure sports-ocean sports tourism mixed passive tourism and eco-natural environmental participating tourism cconcepts for underwater tourism of leports and experiencing for youth. In terms of 21c Jeju International no-visa metropolitan city, its center Jeju city will be faced that resident population inflow, improved economic situation, increased leisure time, ect phenomenia will be necessary for its city to develope active participating style's leports-tourism items differientiating with other local government's items By development of tourism items of eco-natural environmental leisuresports style, Tourism differentiated with the other will be elevated competition and for this future developmental direction must be based on 「ocean-midmountain-orum-sky」 of various ocean tourism leports, golf tourism, aviation tourism leport of participating style's tourism by only Jejudo's natural characteristics. Particularly corncerned with ocean leport tourism of Jeju city, It will be desirable to develop, investment of facility, offer various participate program linking Eho beach-Euyeng cost line point-Leports park-Yongdoam concerned with ocean leport tourism of Jeju city's Euyeng cost load point. When developed of experiencing underwater tourism point, Effects of income level, occupational problem will be futher good condition and offer differentiated tourism items to other local government's.

경영 그랩 출발법의 플랫과 폴드 유형의 운동학적 비교분석

류재청(Che Cheong Ryew) 한국사회체육학회 2001 한국사회체육학회지 Vol.16 No.-

The study was to undertaken to suggest the efficiency of starting technique after kinematic analysis of starting phase between flat and fold type of grab start in competitive swimming The subjects recruited in the study was composed of 3 male of national representative swimmer and the method of analysis was 3D cinematographic technique. 1. Temporal variables Elapsed time by phases was more delayed in starting block supporting than flight phase in both types and starting block supporting phase was more delayed in flat than that of fold type but flight phase was more delayed in fold than that of flat type. Therefore it was considered to improve the record by shorting the starting block supporting time in flat type and by shorting the flight phase time in fold type. 2. C.O.G displacement Forward direction(Y) in starting block after starting signal was shorter in starting block supporting phase than flight phase in both type and was maintained rather higher vertical direction(Z) in flat type than that of fold type in starting phase. That is considered to be relatively more displacement to forward direction in flight phase, 3. Velocity of C.O.G. The velocity of COG in forward(Y axis) and vertical direction(Z axis) was shown faster in flat than that of fold type but slower in flat than that of fold type in forward direction(Y axis). 4. Angular displacement The range of knee extension at TTO-TTE was larger in flat than that of fold type and maintained the same(t=6.16, p<.001). In case hip joint it was shown larger extension in fold than that of flat type during entry phase.(t=-2.69, p<.05). 5. The relationship among variables In flat type, HTO in black supporting phase was shown negative correlation with displacement in forward direction(Y axis) In flight phase, it was shown each negative relation between displacement and with velocity in forward direction and with negative relation displacement and with velocity in starting block supporting phase, negative relation between temporal and with forward direction in flight phase with knee extension in flat type. It shown negative relation between response time and velocity in forward direction and velocity component in forward direction, and velocity component in forward direction and extension of hip joint in starting block supporting phase, and also forward direction velocity with range of knee extension in flight phase.

대형화물 트럭의 운전석에서 점프 시 착지기술이 다리강성과 COP변인에 미치는 영향

류재청 ( Ryew Che-cheong ),현승현 ( Hyun Seung-hyun ) 제주대학교 해양스포츠센터 2018 해양스포츠연구 Vol.8 No.2

The purpose of this study was to investigate the effect of landing techniques on center of Pressure and leg stiffness during jumping from driver's seat in large-cargo truck. Participants Selected as subject were composed of adult male(mean age: 29.66±6.47 yrs, mean heights: 176.91±3.80 cm, mean weights: 76.16±2.33 kg), and performed descending motions of 2 types(soft and stiff landing). The soft and stiff landing techniques were defined by maximum knee flexion angles(soft landing) of gerater than and less than 90 degrees from full extension(stiff landing), respectively. As a result, dimensionless leg stiffness, peak vertical force(PVF) time, and center of pressure area didn't show significant differences statistically according to the landing techniques. Also, PVF at soft landing motion showed decrease than that of stiff landing motion during jumping from driver's seat in cargo truck. Combined, these results show that jumping from in a driver's seat of large-cargo truck increase the impact force regardless of the landing technique.

연중 최대하 부하 훈련을 통한 수영순서의 유ㆍ무산소성 운동능력 분석

류재청(Che-Cheong Ryew) 한국체육과학회 1998 한국체육과학회지 Vol.7 No.1

잠수활동에서 혼합가스 호흡과 감압증(잠수병)의 고찰

류재청 ( Che Cheong Ryew ) 제주대학교 해양스포츠센터 2012 해양스포츠연구 Vol.2 No.1

The aim of the study was to review the effects of mixtures breathing gases on the decompression sickness(DCS), which was divided into embolism, inert gas narcosis, and oxygen balance as decompression syndrome explained in previous studies in diving. Certainly most established diving practices try to avoid situations which one or another, or combinations, threaten a diver. To prevent those, mixed breathing gases, across a spectrum of activities, have been utilized successfully, which mostly consist of mixtures of nitrogen, helium, and oxygen, differing from pure air, and lately those with higher oxygen content than air(enriched), which can be employed efficiently in shallow diving. Non-enriched mixtures of nitrogen/oxygen(nitrox), helium/oxygen(heliox), and helium/nitrogen/oxygen(trimix), of course, have been employed commercially in deep and saturation diving. Recently, mixtures of hydrogen/oxygen(hydrox) have been tested. Furthermore, for precise examination of the mixture of more breathing gases` effects in underwater activities, it may be necessary to test the influence of mixtures breathing of quadrox(nitrogen/hydrogn/ helium/oxygen for effective activities.

외발서기 시 무릎 보호대의 착용이 균형성에 미치는 영향

류재청 ( Ryew Che-cheong ),현승현 ( Hyun Seung-hyun ) 제주대학교 해양스포츠센터 2017 해양스포츠연구 Vol.7 No.2

The purpose of this study was to investigate the effect of knee compression band on balance during single-leg stance. The participants consisted of healthy adult male(n=9). The analyzed variables included of the ΔCOP(center of pressure)x, ΔCOPy, CDP area, medial-lateral COP, and anterior-posterior COP during single leg stance. As a result, Δ COPx, Δ COPy, and COP area didn't show significant differences statistically according to the bilateral stance legs(p>.05), but wearing of knee compression band showed decrease than that of non-wearing of knee compression band(p< .01). Also, ML COP didn’t show significant differences statistically according to the bilateral stance legs and wearing of knee compression band(p >.05), while, AP COP at dominant leg(right leg) showed decrease than that of non-dominant leg(left leg) during one stance leg(p<.05). Combined, these results show that knee compression band may provide both a performance enhancement and an injury reduction role during static-based posture control.

승마 평보 시 숙련자의 등자길이 피팅에 따른 기승자세정열의 운동학적 비교분석

류재청 ( Che Cheong Ryew ),현승현 ( Seung Hyun Hyun ) 한국운동역학회 2014 한국운동역학회지 Vol.24 No.4

The purpose of this study was to analyze of the rider postural alignments according to the fitting of stirrups lengths during walk of high level riders. Participants selected as subject were consisted of horse riders of high level (age: 47.66±3.51 yrs, height: 168.40±4.84 cm, body weight: 73.36±15.58 kg, low extremity length: 94.76±3.98 cm, career: 23.33±5.77 yrs) and walk with 3 types of stirrup lengths(ratio of low extremity 68.04%, 73.25%, 78.48%). The variables analyzed were consisted of the displacement of Y axis (center of mass, head, thigh, shank and foot), FR angle, LR angle, dynamic postural stability index (DPSI), coefficient of variation (CV%), and distance (X axis) of low extremity limb between right and left. The displacement of Y axis in COM, thigh, shank, foot limbs were not statistically significant, but movements of head showed greater distance of B type and C type than that of A type during 1 stride of walk. The FR and LR angle in trunk of horse rider, dynamic postural stability index and, coefficient of variation didn`t show significant difference statistically according to the fitting of stirrup lengths. Also the distance (X axis) of low extremity in thigh and shank didn`t show significant difference statistically in between right and left, but right and left foot showed greater distance in C type than that of B and A types during walk in horse back riding. The hip and ankle joint angle not statistically significant according to stirrups lengths, But knee joint angle showed more extended according to the increase of stirrups lengths during stance and swing phase in walk.

잠수장비 착용 이동시 힐 높이에 따른 보행형태 분석

류재청(Che Cheong Ryew) 한국사회체육학회 2009 한국사회체육학회지 Vol.0 No.38

The purpose of this study was to suggest optimal height of diving shoes by investigation of kinematic relation between optimal load and height of heel during gait according to heights of shoes` heel with load of SCUBA apparatus. The results of this study was summarized as follow. 1. In elapsed time of 1 stride, there was longest in 4cm but shortest in 1cm of heel height. Therefore It was assumed to be optimal heel height in 2cm-3cm. 2. COG displacement in forward direction(Y-axis) was most stable and optimal in 2cm-3cm of heel height during gait according to heights of shoes` heel with load of SCUBA Equipments. 3. When considered the fastest COG velocity of forward direction(Y-axis) in 2cm-3cm of heel height, it was assumed to be close relation between temporal and forward direction displacement of COG. 4. By minimization of flexion range of proximal & distal segment in 2cm-3cm of heel height, It was assumed to be stable gait. Therefore in later study, It was necessary to investigate relation between load, heel height and body position of loads attached the SCUBA equipments.