인암(仁庵) 정철정(鄭哲正) 교수(敎授) 정년퇴임(停年退任) 기념(記念)

정철정 ( Chul Jung Jung ) 한국운동역학회 2009 한국운동역학회지 Vol.19 No.1

Disciplinary Biomechanics : 유도 기술의 현장 적용을 위한 생체역학적 분석

김의환,정철정 ( Eui Hwan Kim,Chul Jung Jung ) 한국체육학회 1994 국제스포츠 학술대회 Vol.1994 No.-

도마 손 짚고 몸펴 앞 공중 돌아 540도 비틀기의 운동학적 분석

여홍철,윤희중,류지선,정철정,Yeo, Hong-Chul,Yoon, Hee-Joong,Ryu, Ji-Seon,Jung, Chul-Jung 한국운동역학회 2003 한국운동역학회지 Vol.13 No.3

The purpose of this study was to investigate the differences of the kinematical and the kinetical factors that calculated from preflight to postflight of salto forward straight 3/2 turn motion between skitters and less-skitters. four S-VHS video cameras operating at 60Hz were used to record the performances. five elite male gymnasts were participated in this study as subjects. three-dimensional coordinates of 20 body landmarks during each trial were collected using a Direct Linear Transformation method. The digitized body landmarks were smoothed using a Butterworth second order with low pass digital filter and a cutoff frequency of 10Hz. 1. A skitter, got a high score for performance, showed shorter time and faster horizontal velocity than a less-skitter at the board contact. also, a skitter extended quickly his knee and hip joint after contacting board for preflight phase. 2. A skitter revealed faster time and horizontal velocity the vault from taking off board than a less-skiller. A skitter took a long time and high distance to get the vertical peak compared with a less-skiller. 3. For the second phase, a skitter, who executes the most optimal motions among the subjects, displayed a long flight time, a high height, and a far flight distance as well as maintaining consistent horizontal speed even at the peak of post flight. On the other side, a less-scorer displayed a slow vertical velocity, distance and a short time at the point of take-off from vault as well as low height at the peak of post flight.

달리기 속도와 방향전환 각도에 따른 하지관절 움직임 분석

권오복 ( Oh Bok Kwon ),정철정 ( Chul Jung Jung ) 한국운동역학회 2007 한국운동역학회지 Vol.17 No.1

유도의 선택된 메치기 기술 발휘시 매트반력에 관한 실험적 연구

김의환(Kim, Eui-hwan),강충식(Kang, Choong-shik),정철정(Jung, Chul-jung) 용인대학교 무도연구소 1992 武道硏究所誌 Vol.4 No.1

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.

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.

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.

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.

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.