人間 步行動作의 生理學的 Parameter 硏究

鄭哲正,孫泰烈,趙顯喆 成均館大學校 科學技術硏究所 1985 論文集 Vol.36 No.1

Integrated electrical activity(IEMG) from the tibialis anterior muscle and acceleration and ECG were simultaneously measured by two subjects during the walking performed on a treadmill set at 3km /h to 8km/h. Within the range of steady states measured, where no mounting fatigue was likely, both IEMG and HR, Acceleration were linearly related to the walking speed by the subjects. The mean liner correlation coefficient for the IEMG/Walking speed relationship was generally above 0.99 as were those for both the HR/W. Speed relationship and Accl./W.Speed relation-ship. Also the vertical accelerator(Av) of centers of gravity of the body in human walking was directly proportional to the walking speed untill 7km/h. But the Av. at 8km/h was changed to lange especially and that speed (8km/h) was guessed to limit of the normal walking pattern. It appears for heart rate to increase progressibly with along the walking speed, and until 7km/h nomal walking patterns can be possible, but after that time, Such a nomal walking pattern can be impossible and fast increasing result was reasonable at 7-8km/h, because a high heart rate lowers the mechanical efficiency of the heart and increases the oxygen uptake for a given cardiac output.

鐵棒 흔들어 차오르기 技術의 映像分析

鄭哲正 成均館大學校 1979 論文集 Vol.26 No.-

For investigation of the kinetic and kinematic aspects of the kip on the horizontal bar, five performers (two expert gymnasts, a mid-level performer, two low-level performers) performed three trials each, and were photographed with a 16mm Bell & Howell motion picture camera at 42 frames per second. And determined the placement of shoulder joint, center of gravity (C.G.) and ankle joint in initial and final phase of forward swing, hip flexion, hip extension and ascension of C. G. from composite figures. Results and Conclusion: Hip flexion was always found to occur before the C.G. reached the end of the forward swing in low level performers. The distance from the bar to the C.G. shortened and the angular momentum generated in the first half of the forward swing was maintained for a longer period. The C.G. also reached a highly potential energy which was used during the hip extension and ascension phases. Expert gymnasts occurred initiation of hip extension when the C. G. had reached almost a point directly beneath the bar. The greatest forces occurred when the C.G. was directly beneath the bar during the hip flexion and immediately after the initiation of hip extension. The largest bar displacement occurred at the latter instant, however, the larger calculated reaction forces occurred at the former instant.

FRONT HANDSPRING 動作의 力學的 分析

鄭哲正 成均館大學校 1980 論文集 Vol.27 No.-

The purpose of this study is to biomechanical analyze at the skill factors in Front Handspring with cinematography. The right side views of 10 expert performers and 7 non-expert performers were filmed at 64 frames per second by a 16mm high speed motion picture camera (Bell & Howell 70 DR), with the black marks pointing each to head (parietale), shoulder (akromion), elbow (rabiale), wrist (stylion), hip (greater trochanter), knee (tibiale), and ankle (sph yrion). Each frame of these films was projected on screen (scale rate 100 : 11) for tracing. Then, the distance, degree and time of three phases (Hopping, Kicking, Landing) were measured and analyzed in all he tracing figures. Means and standard deviations of some results were as follows; 1. Hopping distance: exp. perf. ; 160cm, 13.8cm non-exp, perf. ; 124cm, 20.4cm 2. Hopping height : exp. perf. ; 105cm, 10.7cm non-exp, perf. ; 91cm, 3cm 3. Hopping time: exp. perf. ; 0.579sec, 0.043sec non-exp, perf. ; 0.460sec, 0.036sec 4. Rear leg kicking angle: exp. perf. ; backward 18.6°, 3.2° non-exp, perf. ; forward 9.4°, 5.4° 5. Hand landing time: exp. perf. ; 0.247sec, 0.021sec non-exp, perf. ; 0.274sec, 0.034sec 6. Knee angle as feet landing: exp. perf. ; 151°, 4.2° non-exp, perf. ; 108°, 3.1° 7. Time from skip to landing; exp. perf. ; 1.326sec, 0.54sec non-exp, perf. ; 1.227sec, 0.145sec Conclusions were as follows; 1. The hopping movement that leads into the handspring of expert performer is vigorous and made with his body inclined forward and the non-hopping leg extended behind. 2. The angular momentum of expert performer is added to by the strong upward swing of his rear leg and by the movement of his weight on a horizontal axis through the ankle of this front leg. 3. Upon his hand landing, the hip, shoulder, and wrist joints of expert performer are in an approximately straight line. 4. The expert performer contracts the appropriate muscles of this wrists and shoulders, and thrusting forcefully against the floor lifts his body into the air, as his hip joint passes forward and over his hand.

步行時 足低의 接觸에 관한 硏究

鄭哲正 成均館大學校 科學技術硏究所 1984 論文集 Vol.35 No.2

The ground reaction forces during normal level walking have been investigated by several authors and are described, for example, in Cunningham (1958) and Harpper et al. (1961). The purpose of this paper is to explain the reaction forces-time during stance phase in normal gaits. The subjects was four normal adults and the test subjects walked on the level straight board and force platform at various cadences (80, 120 and 160 steps per min.) The ground reaction forces (G.R.F) and time were obtained by force platform (TAKEI) and high speed camera. (Bell & Howell, 64 frames/sec) The G.R.F was increased according to the walking speed at initial and final stance phase. The stance time of left foot was taken longer than right foot. The G.R.F of right foot during stance phase was larger than left foot. Therefore, the rear edge and fore edge of right shoe were more worn than left shoe.

體育科 入學實技考査 改善에 관한 硏究

鄭哲正 成均館大學校 1982 論文集 Vol.31 No.-

The purpose of this study is to find the new entries of physical fitness and motor ability test in entrance practical examination on winter. The subjects were 120 general highschool students, 100 physical education high school students, 115 general students of college and 85 physical education department students of university. The subjects were tested; (1) 10M shuttle run, (2)20M shuttle, (3) 100M dash, (4) 1000M run (5) step-up test (similar Havard step test) (6) standing broad jump, (7) running broad jump (8) basket ball throw, (9) handball throw. As a result, the following entries were selected as alternatives which can be adopted for indoor tests:namely 20M shuttle run, step-up est, standing broad jump, and basketball throw. Conclusion: To conduct all motor ability tests in entrance practical examination for department of physical education, which were conducted outdoors in the past, indoors.

水泳 Front Crawl 競技에서 速度와 Stroke 頻度數, 길이와의 관계

鄭哲正 成均館大學校 科學技術硏究所 1983 論文集 Vol.34 No.2

The present study was undertaken to investigate the relationships of stroke frequency (cycles/sec), stroke distance (m/cycle), and velocity (m/sec) in the front crawl competitive swimming (event : 100m 200m race) and to reveal the change rate of records, velocity, SF and SD between elementary school, middle school, high school student and college & general swimmer. The subjects were 110 competitive swimmer of final events who participate in Dong-A Swimming Competition which was held in a 50m pool in Seoul, August in 1983. The times of every race were recorded electronically. Strokes frequency during each 50m lap were measured by reach observers. The SF and SD were calculated for each subject. It was found in this study that V is related to SD in all events, but has no relation to SF. But in the case of U. S. Olympic swimmers, V is significantly related to SF. From these results, it is suggested that improvement of velocity of Korea competitive swimmer, especially national swimmer during front crawl racing depends upon an increase of SF and SD.

한국 대학의 생체역학 교육과정 및 교육내용

정철정 한국운동역학회 1993 한국운동역학회지 Vol.3 No.1

100m 달리기의 운동학적 요인 분석 : 고등학교 남자 선수를 대상으로 For male high school runner

정철정,이종훈 한국운동역학회 1996 한국운동역학회지 Vol.6 No.1

본 연구의 목적은 100m 달리기 구간에서 일어나는 운동학적 변인들을 알아보고자 최대 속대 구간과 마지막 구간을 설정하여 시간 요인, 속도 요인, 거리 요인으로 나누어 분석하였다. 그 결과 최대속도 구간의 평균 속도는 9.70m/s, 마지막 구간의 평균 속도는 8.37m/s로 9.96%가 감속되었다. 또한 최대 속도 간간에서는 평균 지지시간은 0.11초, 마지막 구간에서는 0.13초로 속도가 감소할수록 지지시간이 증가함을 보였다. 그리고 최대 속대 구간에서 마지막 구간으로 평균속도가 9.96% 감소하였으며, 보속은 7.80%가 적어졌다. 한편 신장과 하지장간은 밀접한 상관이 있는 것으로 나타났으나 보속과 보폭은 역상관관계로 나타났다. 보폭은 최대 속도 구간과 마지막 구간에서 차이가 없었으며, 비행시간과 평균 속도와는 상관이 없는 것으로 나타났다. The purpose of this study is to know the kinematical factors happening in 100m running phase. Represenfative 10 high school runners in Seoul are studied, using the maxmum speed phase and final phase. In addition, 3 factors such as time, speed, distanced, are analysed by comparison. 1. The average speed in maximum speed phase is 9.70m/s and the average speed in final phase is 8.37m/s, which is the 9.96% decrease of the speed. 2. The average support time in maximum speed phase is 0.11(s) and in final phase 0.13(s). This shows that the more the speed decreases the more the support time increases. This is an important factor in downing the record of 100m running. 3. When the speed comes down in 9.96% of the average speed from the maxmum speed phase to final phase, the stride frequency decreases by 7.8%. 4. Height has a very close relation with leg length, having 0.88 correlation of coefficient. Stride frequency has a anticorrelation coefficient. 5. There is little difference between the stride lenghts in the maxmum speed phase and finnal phase. 6. There is no significant differences between the flight time and the average speed.

관절중심( Joint Center )에 관한 연구

정철정,주영화 한국운동역학회 1999 한국운동역학회지 Vol.9 No.1

The purpose of this study is to suggest joint centers for the sake of appearance for digitizing on the precise joint center through analytical studies on some X-ray photographs of the wrist joint, elbow, shoulder joint, ankle joint, knee joint, and hip joint. In order to achieve the set purpose, a healthy, male adult who has no ailment of joins and whose height is 170 cm and whose weight is 70Kg was selected as a subject for this study and assumed landmarks were dotted. Findings are as follows: 1. It appeared that when a landmark of wrist joint is put on or attached to the line connecting both those distal salients of the spine and radius, it passes the wrist joint center relatively precisely. 2. it appeared that when a landmark of elbow joint is attached to a spot 1cm inward from the center of the connecting line of line of the crista(projection) while fingering or touching the elbow, it passes the elbow joint center. 3. It appeared that regarding the shoulder joint as a joint whose center is difficult to be digitized, its center moved 2㎝ inward and 3.5㎝ upward at a horizontal posture and it moved 4.8㎝ inward and 5㎝ upward at a perpendicular posture; in case of a horizontal posture, the landmark put on the skin moved 1.5㎝ inward and about 4.5㎝ upward; at a perpendicular posture, it moved 8.2㎝ inward and 9.1㎝ upward. Therefore, the landmark should be attached or put on 2㎝ inward and 3.5㎝ upward at a horizontal posture while it is put on 4.8㎝ inward and 5㎝ upward at a perpendicular posture, in order to find out the shoulder joint center. 4. It appeared that the landmark of ankle joint can pass the ankle joint center when the end of the lower part of the tibia(medial malleolus) and the projecting part of the part of the lower part of fibular(lateral malleolus are connected. 5. It appeared that when a landmark at the knee joint is attached on about 0.8㎝ downward from the junction of the thigh bone and tibia, a precise knee joint center can be found out. 6. It appeared that when a landmark at the hip joint is attached or put on 1 ㎝ inward from the line of a triangular, swimming trunks, and when it is put on 3∼4㎝ upward or downward from the center of greater trochanter, it passes the precise hip joint center.

Developpe a la seconde 동작 시 골반과 하지의 지향각(Orientation angles)의 운동학적 분석

정철정,정혜진 한국운동역학회 2004 한국운동역학회지 Vol.14 No.3

C. J. JUNG, H. J. JEUNG. Kinmatics Analysis of pelvis and lower extremity using orientation angles during a developpe a la seconde. Korean Journal of Sport Biomechanics, Vol. 14, No. 3, pp. 259-270, 2004. The purpose of this study was to analysis of pelvis and lower extremity using orientation angles during a developpe a la seconde. Data were collected by Kwon3D program. Two females professional modern dancer were participated in this experiment. Subjects performed a developpe a la seconde in meddle heights(about 90 deg.) The results were as follows. The orientation angles of pelvis were, in most cases, caused by the movement of trunk and thigh. It was restricted the movement of pelvis within narrow limits because the movement of pelvis was very important to lower extremity alignment. The orientation angle of shank against thigh showed a change of angle about 3-60 in internal ·external rotation The orientation angle of foot against shank showed a change of angle about 6-7 in internal ? external rotation.