잠수용 휜 유형별 신체중심의 추진에 미치는 영향

류재청 한국스포츠리서치 2005 한국 스포츠 리서치 Vol.16 No.5

Sprinting의 競技力 向上을 위한 運動力學的 硏究(I)

李昌俊,柳在靑 제주대학교 1991 논문집 Vol.33 No.-

본 연구는 달리기시 하지 3분절 연쇄계가 상호 작용하여 나온 운동학적, 운동 역학적 변인을 분석하여 현장 훈련에 적용할 수 있는 자료로 삼기 위해 착수하였다. 이를 위해 본 연구의 피험자는 국가대표급 선수 2명을 대상으로 고속카메라를 이용하여 2차원적인 영상분석을 실시하였고 연구 결과를 요약하면 다음과 같다. 1. 신체중심의 속도에서 L-off시점에서 마지막 L-down까지의 패턴이 수직, 수평 속도에서 거의 변화가 없는 것으로 나타났다. 2. 분절의 수평속도 및 수직 속도의 경우 선행 연구의 것 보다 더 큰값을 가졌으며, 이는 처음 국면의 이륙 속도가 더 빨랐음을 의미한다. 3. 가속도 곡선을 볼 때 하지의 각 분절들의 근육이 발휘하는 순서에서 협응동작이 잘 되지 못한 것으로 나타났다. 따라서 발 하지 대퇴의 순서로 근 발휘하는 능력을 키워야 한다. 4. 각변위 및 각속도에서 대퇴의 굴곡정도가 약함으로 인해 탄도기를 더 적게 가졌고, 분절 상호간 협응적인 동작이 서툰 것으로 나타났다. 따라서 관성 모멘트를 크게하여 결국 속도를 느리게 할 수 있다. 각 속도의 경우 하지 분절의 불협응으로 인해 탄도기가 되는 시점이 정상적이지 못했다. 즉 대퇴의 굴곡하는 속도가 제1번 하퇴가 2번 발의 경우가 3번째의 크기로 각속도가 발현될 때 바람직하다. 5. 근 모멘트에서 하퇴 대퇴 발의 순서로 슬굴근 고굴근 배측굴근으로 나타난 바 가장 바람직한 형은 고굴근 술굴근 배측굴군으로 나타나야 한다. The study was undertaken to investigate the mechanism of 3 linked system of lower limb in sprinting. The subjects recruited in the study were composed of 2 athletes of national team athletic department. The experiment was undertaken in 400m track, lateral view of sprinting subject was photographed by photosonic high speed camera in 100 frame per second. The conclusion obtained were as follows; 1. C.O.G. velocity was not shown variation from L-off to last phase L-down in horizontal & vertical velocity components. 2. Segment's vertical & horizontal velocity component was faster than past studies, this meant faster in takeoff phase. 3. The acceleration curve had'nt coordination among segments in contraction order, therefore must educate contraction ability of foot, shank, thigh order. 4. Angular displacement & angular velocity also had not coordination of muscle contraction, therefore can be influenced of greater moment of inertia. 5. Resultant muscular moment had in order of dominant group of knee flexor, hip flexor, dorsiflexor.

레슬링의 그레고로만형의 안아넘기기의 운동역학적 분석

류재청,우철호 국민대학교 1992 北岳論叢 Vol.10 No.1

하지 연쇄계모형에서 수직반력의 증가가 관절토크 유발에 미치는 영향

임상용,류재청 제주대학교 1994 논문집 Vol.39 No.-

본 연구는 하지관절의 근토크를 유발하는 요인을 분석하고 Tatara(1983.1987)의 연구결과를 검증하기 위해 부하를 체중에 대한 부하비율을 설정하고(%BW), 이를 토대로 분석결과 내린 결론은 다음과 같다. 첫째, 보행동작은 수직반력(외적힘, %BW)에 종속요인으로 나타났고, 따라서 하지 분절에 수직반력은 압축작용을 하는 것으로 나타났다. 둘째, 부하의 수준에 따라 히프관절의 토크를 유발하는 요인에서 부하가 40%BW일 때 수직반력은 종속요인으로 수직반력이 관절의 근토크에 미치는 영향은 큰 것으로 나타났으며, 0%BW와 20%BW의 경우는 독립적인 요인으로서 아무른 영향을 미치지 않았다. 세째, 무릎관절의 경우 관절토크와 수직반력과는 독립적인 요인으로 수직반력의 종류에 따라서 관절의 토크유발에 아무른 영향을 미치지 않았다. The study was undertaken to investigate factors generating a joint torque according to load level (%BW) during normal gait. 1) The joint torque during normal gait was influenced to vertical reaction force. The vertical reaction force was played a role of compression force. 2) The factors generating joint torque in lower extremity according to load level was independent role in 40%BW but not influenced in 0%BW, 20%BW load level. 3) The kind of load level(vertical reaction force) did not incluenced knee joint torque, but did in hip joint torque.

런닝화의 밑창(Outer Sole) 높이 변화가 중족 착지(Midfoot Strike)를 유도할 수 있을까?

류재청,김진현 대한운동학회 2014 아시아 운동학 학술지 Vol.16 No.2

[INTRODUCTION] The purpose of this study was to investigate the effect of shoe heel to toe drop differences in strike patterns during running and to examine consistency of strike patterns. [METHOD] Ten healthy females participated in this study. All subjects were recreational runners currently running at least 2 km per week. These subjects preferred the heel strike pattern and ran in conventional running shoes. All trials for each subject were completed on the same day, and the order of shoe conditions was randomized. Each subject was instructed to run with both a heel strike and a midfoot strike. After a period of 3 min on a treadmill at 3.0 m/s the sole angle was measured. We collected sole angle data using camera. The independent variables were strike pattern running and heel to toe drop, and the dependent variable was sole angle at the sole contact. Statistical comparisons were carried out using a two-way analysis of variance with repeated measures (alpha = 0.05) and intra class correlations were used for consistency analysis. [RESULT] The conventional shoes(drop 8 mm) were higher than other conditions(drop 4 mm and barefoot) in sole angle during running. Consistency of midfoot strike patterns were slightly lower in barefoot running and conventional shoe conditions than in the minimalist shoe condition There were significant differences at the sole angle in heel strike running pattern (Figure 1) but there were no transitions for the strike pattern at foot contact. There were transitions in strike pattern when the subjects were instructed to change their running pattern. Otherwise there were no significant differences at the sole angle between drop differences when subjects ran with a midfoot strike pattern. [CONCLUSION] Sole height of running shoes cause to midfoot strike and minimalist running shoe tend to increase the correlation of strike pattern. Sole height of running shoes are one of the cause to change the strike pattern however training program is more important in midfoot running. [서론] 본 연구는 런닝화의 밑창(Outer sole) 높이 변화에 따른 착지패턴(strike pattern)을 분석함으로써 어떠한 신발이 중족착지(Midfoot strike)를 잘 유도할 수 있는지 확인하고자 하였다. [방법] 본 연구의 피험자는 서울소재 K대학에 재학중인 여자 대학생 10명을 대상으로 런닝화의 밑창 높이 변화에 따른 착지패턴을 파악하기 위하여 3차원 동작 적외선 카메라 10대(Vicon MX-T10, T40, UK)를 이용하여 런닝 시작 후 3분 이후의 연속적인 데이터를 사용하였으며, 런닝 속도는 3m/sec로 통제 하였고 총 10회의 초기접촉 시점의 Sole angle 값을 산출하였다. 통계적 처리는 Two-way repeated ANOVA를 사용하였고, 사후 검증은 bonferroni를 사용하였다. 유의수준은 α=0.05로 설정하였다. [결과] drop 8mm 인 런닝화는 drop이 낮은 신발보다 sole angle 값이 높게 나타났다. 중족 착지 패턴의 일관성에 있어서는 맨발 런닝과 8mm 인 런닝화에서 drop이 낮은 런닝화보다 다소 낮게 나타났다. 후족 착지 런닝에 있어 sole angle 값이 통계적 유의한 차이가 있었다. 또한 중족 착지에 대한 교육 후에 중족 착지를 보이는 것으로 나타났으며, 중족 착지를 달리기 시 sole angle 값에서 차이가 나타나지 않는 것으로 나타났다. [결론] 본 연구의 결과로 미루어 볼 때 맨발 착지를 기준으로 밑창 높이가 낮은 신발일수록 중족 착지를 유도하며 착지 패턴의 일관성도 높게 나타났다. 이는 신발의 밑창 높이가 낮으면 중족 착지를 유도할 수 있으나, 중족 착지 런닝 트레이닝 방법, 교육이 보다 중요한 요인일 것으로 사료된다.

스쿠버다이빙활동이 중년여성의 정신건강과 유산소성 운동능력변화에 미치는 영향

류재청 한국스포츠리서치 2005 한국 스포츠 리서치 Vol.16 No.4

숙련자와 미숙련자의 배드민턴 스매시 동작의 운동학적 비교 분석

류재청,김익상 한국운동역학회 2003 한국운동역학회지 Vol.13 No.2

Ryew, C-C and Kim, I-S. Kinematic Analysis of Badminton Smashing Between the Skilled and the Unskilled. Korean Journal of Sport Biomechanics, Vol. 13, No. 2, pp. 139-160. The purpose of this study was to suggest the guideline for scientific and quantitative skill acquisition methods of badminton smashing so that the novice could learn the motions of badminton smashing efficiently. The subject participated consisted of total 6 middle school students of the skilled(3) and the unskilled(3). The cinematographical experimental & Analysis equipments used in the study were composed of two Model D-5100 Video Cameras, a control point, a synchronization timer and Kwon3d motion analysis system. The conclusions obtained were as follows; 1. It was necessary for the unskilled to learn the smashing impact phase in situation of max. Velocity of COG in order to minimize the timing loss phase. 2. Particularly, The power from segments of Power Zone must participate in utilization in sequence of order of trunk-upper arm-forearm-hand-racket segment in both the skilled and the unskilled. 3. Therefore It was necessary for the unskilled to do smashing practice for cumulated sum of absolute & relative velocity transfer into shuttle cock after adjusting anterior-posterior tilting angle and max timing, in sequence of segment recruited.

골프스윙시 신체분절의 기여도 및 지면반력에 관한 연구

류재청 한국운동역학회 1992 한국운동역학회지 Vol.2 No.1

신발 힐의 높이에 따른 보행자세의 운동역학적 분석

류재청,안성규 濟州大學敎 體育科學硏究所 1997 체육과학연구 Vol.3 No.-

This study was conducted to discover the maost desirable height for shoe heels. An analysis of human kinematics and gaits according to different kinds of shoe heel heights was carried out. Walking, which is related to the locomotor and nervous systems, is different from running. It has some unique characteristics such as the double-supporing phase and the pelvis-centered smooth connections with tension and flexion which can make it possible to walk comfortably. The specific goals of this study are as follows: 1. To analyze the variables of gait cycles with respect to shoe heel height. 2. To analyze the variables of linear kinematics with respect to shoe heel height. 3. To analyze the variables of anguiar kinematics with respect to shoe heel height. 4. To discover the ideal heel height to promote a comfortable walking style. Limits of this study: 1. The processes of BSP and Yeadon-kwon were used. 2. The shoe heel heights investigated were 1. 0 cm(ie: bare foot) 2. 3cm 3. 5cm 4. 7cm 3. The equipment used in this experiment comprised of : a Panasonic VCR: VCR analyzer and analysis program: a Kwon "3D Mothion Anaysis" package. 4. The subjects of this experiment were 3 female collage students who are not used to wearing high heeled shoes: all are aerobics instuctors. with an exellent sense of equilibrium. The model of the human body is defined as a rigid body system connected by 19 jonts(for the purpose of this experiment the nose included as an imaginative joint to give precise direction). In order to reduce any displacement which may occur during didgitization. Iandmarkers were attatched to each of the 19 body segments of each subject. The subject were then asked to walk firstly in bare feet and then wearing shoes with a 3cm, 5cm, and then 7cm heel. A video camera zoom lens was used to record the subjects' walking patterns(RTD-LTO-LTD-RTO-RTD) for one complete gait cycle and the direction of the subject was defined wsing X and Y axes. After the digitization and interpolation of all frames the linear and angular variables which are necessary for the study were calculated. The results of this study are as follows: 1. The time taken to complete one gait cycle increases or decreases by a negligable amount as heel heights vary. It appears that the higher the heel is, the longer the length of each stride will be and the greater the horizontal displacement at the center of the body. 2. When a higher heel is worn vetical displacement is increased during the initial phaze of each gait cycle however when a lower heel is worn. vertical displacement is increased in the final phaze of the gait cycle. 3. The average horizontal speed of each phase increases, regardless of the height of the heel. 4. The vertical speed decreases. regardless of heel height in any gait cycle, the speed decreases with each consecutive phaze eg: in a cycle consisting of :RTD-LTO-LTD-RTO-RTD. the initial phaze from RTD to LTO will the fastest movement in the cycle. the speed will decrease with each concecutive phaze in the cycle. The second phaze of the gait (LTO to LTD) will be slower than the first, and the the final phaze (LTD to RTO to RTD) being the slowest in the cycle. (Overall. the rate of decrease in speed in the last the last phaze of any gait cycle is always slower than the decrease of the first two phazes. therefore we can put the last two phazes together to make one final phaze (LTD-RTO-RTD) as the decrease in speed is so small.) 5. For each motion variable, the difference in tension and flextion of lower body joints is not apparent, using any heel height. The tension and flextion in the shank and thigh is negligable with a 5cm or 7cm heel. The tension and flextion is the most apparent when using a 3cm heel. 6. The walking speed changes little according to heel height alterations. The common outcome is that there is a slow increase in speed after the LTO phase, so that when supporting body weight on the right foot, it is very hard to move on to a new 'centered' body weight position. No problem appears when using a 3cm-heel. however when walking bare foot. there is more pressure on L5 and on S1 than with a 3cm-heel. this is because walking is a forward-motion and the center of the body is left behind when walking bare foot. In conclusion, it is the 3cm-heeled shoe that is the most suitable height to promote a comfortable forward walking motion.

여성의 체중과 구두 힐 높이의 변화가 보행동작 시 동적안정성에 미치는 영향

류재청,이애리,현승현 대한운동학회 2013 아시아 운동학 학술지 Vol.15 No.3

[INTRODUCTION] This purpose of this study was to investigate on the change of shoe's heel heights & body weights for dynamic balance on during gait motions in women. [METHOD] We selected subjects of n=15 young and healthy women in 20's age women and divided into 3 group(lean n=5: BMI 18.26±0.15kg/m2, Normal n= 5: BMI: 20.64±0.88kg/m2, Obese n=5: 29.46±4.72kg/m2) and walked with 3 types of shoe's high- heeled(0cm, 6cm, 9cm). Analysis of the gait was conducted by the image analysis method of 3D DLT(direct Linear Transformation)technique. Variables analyzed were consisted of the time, displacement(Y axis), FR angle & LR angle during gait. Two-Way(body weight 3 × shoe's heel heights 3) repeated measure analyses of variance(ANOVA) & post hoc test(Duncan) were performed to accomplish the study purpose. [RESULT] Time elapsed was shortened according to the body weight increase(p<.05), the COM displacement in Y-axis showed the shorter movement according to increase of shoe's heel heights(p<.05). FR angel in trunk showed the relative forward leaning motions according to increase of shoe's heel heights & body weights(p<.05), LR angle in trunk showed the relative ipsilateral & contralateral trunk leaning according to increase of shoe's heel heights & body weights(p<.05). The effect of LR angle according to increase of body weights showed greater than that of shoe's heel heights during gait(p<.05). [CONCLUSION] Considering the above, the effect on the dynamic balance was decreased according to increase of shoe's heel heights & body weights during gait. [서론] 이 연구의 목적은 여성들의 체중과 구두 힐 높이변화가 보행 시 동적안정성에 미치는 영향을 규명하는데 있다. [방법] 본 연구의 대상은 20대 여성 15명으로 젊고 건강한 여성들이었으며, 체중 별 3 그룹과(저체중 5명: BMI 18.26±0.15kg/m2, 정상체중 5명: 20.64±0.88kg/m2, 비만: 5명: 29.46±4.72kg/m2) 3가지 구두 힐 높이(0cm, 6cm, 9cm)로 나누어 실시하였다. 보행 분석은 3차원 영상분석을 실시하였고, 분석변인은 시간과 신체중심의 전후이동변화, 동체의 전후 및 좌우경각을 분석하였다. 본 연구의 목적을 달성하기 위해 반복이원변량분석(체중 3 × 힐 높이 3)과 유의한 차이발견 시 사후검정(post hoc test: Duncan)을 실시하였다. [결과] 연구결과, 체중증가에 따라 보행 시간이 짧게 나타났고(p<.05), 신체중심의 전방이동거리변화는 구두 힐 높이증가에 따라 감소하는 형태를 보였다(p<.05). 동체의 전후경각은 체중과 힐 높이 증가에 따라 상대적인 전경각 자세로 보행하였고(p<.05), 좌우경각은 힐 높이와 체중증가에 따라 측면기울기가 더 커졌으며(p<.05), 보행 시 체중의 증가가 구두 힐 높이의 증가보다 좌우체간기울기에 더 큰 영향을 주는 것으로 나타났다(p<.05). [결론] 본 연구의 결과는 체중과 구두 힐 높이가 증가할수록 보행 시 동적안정성이 감소하는 것으로 판단된다.