골프에서 힘 조절이 샷의 거리와 정확성에 미치는 영향

손지훈(Jee Hoon Sohn),이기광(Ki Kwang Lee) 한국사회체육학회 2011 한국사회체육학회지 Vol.0 No.46

The aim of this research is to explore the concept of adequate power control to optimize distance and precision in golf shot. To control one`s own swing power is an important factor that influences golf shot performance. In this research, The author investigated the golf shot characteristics(distance, radius, club head speed, ball speed, smash factor) and motion variables(stance width, backswing height, cocking angle, X-Factor, pelvis linear velocity, pelvis angular velocity, GRF pattern) at five different condition(70%, 80%, 90%, MAX, RD). Seven athletes with a 1.43 average handicap participated in this research. All were right-handed. For statistical analysis, One-way repeated measures ANOVA was used. Golf shot with feel of a round was similar to 90% power shot. RD condition showed short distance but smaller radius against MAX condition. To control swing power, athletes changed stance width, backswing height, weight shift pattern and pelvis movement radically to target path. They didn`t change cocking angle and X-Factor at BST event.

골프 로브 샷 타구 기법에 대한 운동역학적 해석 -피치 샷 타구 기법과 비교하여-

손지훈 ( Jee Hoon Sohn ) 한국스포츠정책과학원(구 한국스포츠개발원) 2011 체육과학연구 Vol.22 No.4

이 연구는 웨지를 이용한 일반적인 어프로치 샷(피치 샷)과 다소 응용된 형태인 로브 샷 동작의 유사성과 차이점을 비교·분석하여 로브 샷의 구현 원리를 찾고자 시행되었다. 현역 프로 선수와 대학 선수 등 총 6명의 골프 숙련자를 이 실험의 연구 대상자로 선정하였으며, 이들은 모두 오른 타석을 이용하였다. 어드레스, 미들오브 백스윙, 백스윙 탑, 미들 오브 다운스윙, 임팩트, 미들 오브 폴로스루 그리고 오른발·왼발의 지면반력 값이 최고가 되는 시점 등을 이벤트로 설정하였고, 각 이벤트 사이의 시간 변인을 분석하였다. 또한 스탠스 크기, 백스윙 크기, 코킹 각도, 클럽 헤드의 스윙 궤도, 왼쪽 발과 골반의 타겟 방향에 대한 열린 정도, 지면반력 등을 분석 변인으로 설정하였다. 30m 어프로치 샷의 일반적인 형태인 피치 샷에 비해 로브 샷을 구사할 때에는 어드레스부터 스탠스를 넓히고 신체를 타겟 방향 쪽으로 오픈 시킨 후, 백스윙을 크게 가져갔으며, Out-In 스윙을 하는 것으로 나타났다. 백스윙 탑에서의 20° 가량 더 코킹 하였으며, 임팩트 후 리코킹 하는 형태를 보여주었다. 골반의 각도는 어드레스에서 6° 정도 열려있던 것이 백스윙 탑에서는 거의 같아졌으나 임팩트 때에는 다시 10° 이상 차이가 나타났다. 오른발의 지면반력 값은 스윙 전반에서 두 샷 간에 큰 차이가 없었으나 왼 발의 지면반력 값은 미들 오브 다운스윙 시점부터 임팩트 까지 차이가 났는데, 로브 샷의 경우 다운스윙 초기에 타겟 방향으로 체중을 거의 이동한 후, 임팩트를 한 것을 알 수 있다. 다운스윙 구간에서 샷의 소요시간은 스윙의 크기와 다른 동작 변인들의 차이에도 불구하고 차이가 없었으나, 세부 구간별로는 서로 다른 템포를 보여주었는데, 이로부터 로브 샷의 경우 클럽 헤드의 속력이 미들 오브 다운스윙부터 미들 오브 폴로스루까지 유의하게 빨랐음을 알 수 있다. 이러한 실질적인 로브 샷에 대한 운동역학적 분석은 샷에 대한 과학적 이해를 돕고 아마추어들이 좋은 로브 샷을 하기 위해 평소에 어떤 동작으로 훈련을 해야 하는가에 대한 답을 줄 것으로 기대 한다. In this research we investigated the method how we could make a shot having high trajectory and shorter runs against barriers. We compared the 30m-approach-shots: pitch and lob. Six candidates playing as KPGA tour professionals, college & high school level students participated in this research and they were all right-handed people. Time phase between each event, distance between right and left foot at address and impact event, club head height at backswing top event, club head swing path, left foot and pelvis rotation angle to the target at each event were calculated. Also L-GRF, R-GRF and left wrist cocking angle at all events were analyzed. For statistical analysis the paired T-test was used. Left foot and pelvis rotation angle were significantly different between two shots. Lob shot`s stance width was bigger and backswing height was higher. Lob shot showed Out-In swing path. Cocking angle was smaller at backswing top, middle of downswing and follow through event in the case of lob shot. Left GRF was bigger at middle of downswing event comparing with pitch shot. The result showed that when we made a lob shot having higher trajectory and shorter runs we had widen stance and open our body to the target. We moved our weight quickly to the left during downswing with cocked wrist and maintain Out-In club head swing path at impact event.

골프 샷의 임팩트 전·후 GRF Peak 값의 크기와 타이밍에 관한 해석

손지훈(Sohn, Jee-Hoon) 한국체육과학회 2011 한국체육과학회지 Vol.20 No.5

The aim of this research is to explore the concept of adequate weight shift. Weight shift is an important factor that influences golf shot performance. In this research, I investigate the GRF peak value and timing differences between athletes and novices. Six athletes with a 1.17 average handicap and seven university faculty members, with a 20.29 average handicap, participated in this research. All were right-handed. Time phase between events and right and left foot GRF peak value for all events were measured. Center of mass speed and acceleration were also calculated. For statistical analysis, the paired T-test was used. In the case of the athletes group, all participants show the same pattern: LPEAK occurs just before IMP. RPEAK occurs between MBS and BST. In the case of the novice group, they show five different patterns of LPEAK and four different patterns of RPEAK. The athletes group’s left foot GRF is as large as 1.47 times at MDS event and 1.54 times at IMP event, compared to the novice group. However, right foot GRF is smaller at all events except MBS. Also, COM speed decreases radically between MDS and LPEAK.

샌드웨지 어프로치 샷의 거리 조절 동작 변인 탐색

손지훈(Jee Hoon Sohn),최형준(Hyung Jun Choi) 한국사회체육학회 2012 한국사회체육학회지 Vol.0 No.49

The aim of this research was to identify optimal sets of important variables to control sand-wedge shot distance. The authors investigated on the golf shot characteristics(distance, radius, club head speed, ball speed, smash factor) and 8 motion variables(stance width, backswing height, cocking angle, X-Factor, thorax angle, pelvis linear velocity, pelvis angular velocity, GRF pattern) a t five different events(AD. TBS, MDS, LPEAK, IMP). Nine athletes with a 5 average handicap participated as subjects in this research. As results of this research, two estimated models based on MLR models were found. First model(adjusted R2=.929, F=5.667) was contained backswing height, cocking angle(TBS), stance width, cocking angle(IMP), Left-foot GRF(IMP), pelvis angular velocity(MDS) and Right-foot GRF(LPEAK) in order. Second model(adjusted R2=.929, F=1.670) was contained backswing height, cocking angle(TBS), stance width, Left-foot GRF(IMP), pelvis angular velocity(MDS) and Right-foot GRF(LPEAK) in order.

의도적인 드로우 샷과 페이드 샷이 골프 스윙 역학에 미치는 영향에 관한 연구

손지훈 ( Jee Hoon Sohn ),류재진 ( Jae Jin Ryue ),이기광 ( Ki Kwang Lee ),임영태 ( Young Tae Lim ) 한국운동역학회 2010 한국운동역학회지 Vol.20 No.2

Intentional draw and fade shots could be good weapons for lowering golf score. But how to make such shots? To investigate deterministic variables generating different projectile paths of shots in square stance was the purpose of this study. Ten right-handed male collegiate athletes, showing 1.3 of averaged handicap, participated in this study. They were asked to intentionally perform three different shots such as the straight shot(control condition), draw shot, and fade shot. Swing path, pelvis rotation angle, thorax rotation angle and left forearm supination angle were determined for dependent variables on impact event at each trial. For statistical analysis one-way repeated measures ANOVA were used. The results showed that swing path was one of main factor making differences among three kind of shots. Straight shot vs. Draw shot, Straight shot vs. Fade shot and Draw shot vs. Fade shot showed differences on swing path. And left forearm supination angle revealed significant difference between draw shot and fade shot, showing a significant larger angle of draw shot than fade shot. No other significant difference was detected for the other variables. We found that the shot characteristics were influenced primarily by swing path and left forearm supination angle.

골프 실제 샷과 빈 스윙의 동작 특성 비교 연구

손지훈(Sohn, Jee-Hoon),박용현(Park, Yong-Hyun) 한국체육과학회 2012 한국체육과학회지 Vol.21 No.5

Practice swings are considered useful methods to increase one"s golf skills. A practice swing is a swing done without a ball. In this research, we investigate the differences between a real shot and a practice swing. Ten university faculty members, with a 18.10 average handicap, participated in this research. Time phase between events and club head speed for all events were calculated. Pelvis rotation angle, thorax rotation angle to the target, elbow"s flexion-extension angle, and left wrist cocking angle for all events were analyzed .Also, Left foot GRF and Right foot GRF were measured. For statistical analysis, the paired T-test was used. There was no significant difference in motion and tempo during the backswing phase. But real shots and practice swings were different during the downswing, especially at the middle of the downswing and the middle of the follow through. In the case of practice swings: cocking angle was smaller at the middle of the downswing and the middle of the follow through. The club head speed was slower at the middle of the downswing event, but similar at the impact event. Left foot GRF was smaller at middle of the downswing, and larger at the middle of the follow through.

스포츠공학 연구 동향 탐색을 통한 운동역학 분야 확장 방향 모색

손지훈 ( Sohn Jee-hoon ),양종현 ( Yang Jong-hyun ) 한국융합과학회 2022 한국융합과학회지 Vol.11 No.8

연구목적 본 연구는 스포츠공학 분야에서 가장 저명한 학술지를 분석하여 스포츠공학 분야의 최근 연구 동향을 탐색하는 것에 목적이 있다. 연구방법 이를 위해 ISEA에서 발간하는 Sport Engineering 저널에 출판되어 있는 최근 3년간(2020~2022)의 논문 62편 중 56편의 연구 내용을 분석하였다. 결과 스포츠공학 분야의 주된 연구 분야는 장비 개발 및 검증이었으며, 실험적 연구가 가장 높은 비중을 차지했다. 공학 분야와 관련된 논문이 주를 이루었지만 비율이 매년 감소하였고, 운동역학 분야는 증가하는 추세를 보였다. 결론 스포츠공학은 현재 공학 계열이 주도하고 있는 전도유망한 신생 연구 분야이다. 한국에서도 체육 계열, 특히 운동역학 분야에서 세계적 스포츠공학 분야의 흐름을 받아들이고, 관련 연구를 시작해 나갈 필요가 있다. Purpose The purpose of this studyﾠis to explore the recent research trends in the field of sports engineering by analyzing thesis data of the most prominent academic journal in this field. Methods Out of 62 papers published in the last three years (2020-2022) in the Sport Engineering Journal published by ISEA, 56 were analyzed. Result The main field of research of sports engineering was equipment development and verification; however, experimental research accounted for the highest proportion. Although papers related to engineering were predominant, the ratio decreased every year; and the field of sports biomechanics gained popularity. Conclusion Sports engineering is a promising field of research led by the engineering. In Korea, it is necessary to accept the flow of global sports engineering and start related research in the field of physical education, especially related to sport biomechanics.

골프 스윙 시 선수와 비선수의 두부 분절 움직임 패턴 비교: 골프 헤드업에 관한 해석

손지훈 ( Sohn Jee-hoon ),구도훈 ( Koo Do-hoon ) 한국융합과학회 2022 한국융합과학회지 Vol.11 No.8

연구목적 본 연구는 골프 샷의 명언 중 하나인 'Do not head up'에 대한 운동학적 분석을 수행하고 그것을 해석하는 것에 목적이 있다. 연구방법 엘리트 골프 선수 8명과 비선수 10명의 5번 아이언 샷을 측정한 뒤, 스윙 구간 전체에서 머리 움직임 변화를 분석하였다. 스윙 구간은 어드레스(AD), 미들 오브 백스윙(MBS), 백스윙 탑(BST), 미들 오브 다운스윙(MDS), 임팩트(IMP), 미들 오브 폴로스루(MF)로 구분하였다. 적외선 기반 3차원 동작분석 시스템을 사용하였다. 머리 분절 좌우 관자놀이에 부착한 2개의 적외선 반사 마커 중심을 머리의 움직임으로 정의하였다. 골프 스윙 시 정의된 머리 분절의 3차원적 움직임을 집단 간 비교하였다. 결과 선수의 경우 머리의 움직임이 백스윙 시 우측(-y 축 방향), 하방(-z 축 방향)으로 움직임이 나타나고, 다운스윙 시 좌측(+y 축 방향), 후방(-x 축 방향), 하방(-z 축 방향) 의 방향으로 3차원 공간에서 머리 움직임이 나타났다. 비선수들은 백스윙 시 이미 머리 위치가 높아지면서 임팩트 시 머리 위치가 충분히 내려오지 못하는 패턴을 보였다. 선수들은 다운스윙 시 일관된 머리 움직임이 타나났으나, 비선수의 경우는 피험자 간 각기 다른 패턴의 머리 움직임을 보였다. 결론 골프 코칭 시 '머리를 들지 마라라는 격언으로는 부족하다. 골프 스윙 동작 시 머리 움직임의 3차원적 피드백이 제공되어야 올바른 머리 움직임을 바탕으로 골프 스윙이 이루어질 수 있을 것이다. Purpose The purpose of this study is to analyze the head movements of elite golfers and non-players during golf swings to interpret the meaning of head-ups kinematically. Method After measuring the 5th iron shot of 8 elite golfers and 10 non-players, the change in head movement was analyzed throughout the swing section. Swing sections were divided into address (AD), middle of back swing (MBS), back swing top (BST), middle of down swing (MDS), impact (IMP), and middle of through (MF). An infrared-based three-dimensional motion analysis system was used. The center of the two infrared reflective markers attached to the left and right temples of the head segment was defined as the movement of the head. The three-dimensional movements of the head segment defined during the golf swing were compared between groups. Result In the case of the eltie golfers, the movement of the head appeared in the right(-y axis direction) and downward directions(-z axis direction) during the backswing, and the movement of the head appeared in the three-dimensional space to the left(+y axis direction), post direction(-x axis direction), and downward(-z axis direction) directions during the downswing. Non-elite golfers showed a pattern in which the head position was not sufficiently lowered during impact as the head position was because of already increased haead position during the backswing. The elite golfers showed consistent head movements during downswing, but in the case of non-athletes, they showed different head movements between subjects. Conclusion When coaching golf, the adage Do not head up is not enough. In the case of a golf swing motion, three-dimensional feedback of the head movement might be provided so that the golf swing can be achieved based on the correct head movement.

골프 선수들의 실제 샷, 빈 스윙, 배트 스윙 비교 연구

손지훈(Sohn, Jee-Hoon) 한국체육과학회 2013 한국체육과학회지 Vol.22 No.5

Practice swings are considered useful methods to increased one"s golf skills. Golf swing bats, as a swing aid, are considered useful apparatus among amateur golfers. In this research, we investigate the differences among real shot, practice swing and golf bat swing. Five professional golfers with a 2 average handicap, participated in this research. Time phase between events and COG height for all events were calculate. Pelvis rotation angle, pelvis lineal velocity, pelvis angular velocity, thorax rotation angle to the target, elbow"s flexion-extension angle, and left wrist cocking angle for all events were analyzed. Also, left foot GRF and right foot GRF were measured. For statistical analysis, one way repeated measures ANOVA was used. There were no significant differences in motion and tempo during the backswing phase between real shot and practice swing. But cocking angle, thorax angle and L-GRF at MF event were different. Real shot"s time duration, IMP to MF, was longer than practice swing because of ball collision. There were some significant differences in motion and tempo during the downswing phase between real shot and bat swing. Bat swing took longer time than real shot during TBS-MDS phase. At MF event, cocking angle, L-GRF, right elbow angle, thorax angle and pelvis angular velocity were different between real shot and bat swing.

골프 Fat shot에 대한 운동역학적 분석

손지훈(Jee-Hoon Sohn) 한국콘텐츠학회 2013 한국콘텐츠학회논문지 Vol.13 No.10

Fat shot은 골프에서 공보다 뒤땅을 먼저 치게 되는 샷의 공식 용어이다. 본 연구에서는 fat shot과 정상적인 샷의 동작을 비교?분석하였다. K 대학교 교원 5명을 연구대상자로 선정하였으며, 개인별 fat shot이 최소 5개 체크될 때까지, 샷을 계속하게 하였다. AD, MBS, TBS, MDS, IMP, MF를 분석 시점으로 설정하였고, 구간 소요시간, 지면반력 패턴, 백스윙 크기, 팔꿈치 각도, 코킹 각도, 골반과 몸통의 회전, 골반 선속도?각속도 등을 분석하였다. 변인별 차이를 확인하기 위해 대응표본 검증을 실시하였다. Fat shot의 주요 원인으로 간주되는 다운스윙에서의 빠른 코킹 풀림, 다운스윙 초기의 오른 팔꿈치 신전, 뒷발에 체중을 실은 채로 하는 스윙 등의 형태는 나타나지 않았다. 백스윙 크기와 X-Factor 크기, 골반과 몸통의 회전각도, 골반의 회전각속도에서도 두 샷 간 차이가 나지 않았다. 그러나 정상적인 샷에 비해 Fat shot은 다운스윙 초반이 아닌, 후반부 임팩트 바로 직전의 다소 급격한 체중 이동 형태와 다운스윙 과정 중 골반의 타겟 방향으로의 급격한 가?감속, 그리고 골반의 수직 상방으로의 다소 작고 늦은 타이밍의 움직임 속도 패턴을 나타내었다. When the golf club hits the ground prior to making contact with the golf ball, we define it as fat shot. The aim of this research was to investigate the difference between normal shot and fat shot in golf. Five candidates playing as recreational golfer participated in this research and they were all right-handed people. Time phase between each event, wrist cocking angle, elbow extension-flexion angle, backswing height, pelvis angle, thorax angle, L-GRF, R-GRF, pelvis linear velocity, pelvis angular velocity and COG path were calculated. For statistical analysis the paired T-test was used. An early un-cocking, an early right elbow extension and impact with leaving their weight behind foot were not reasons of fat shot. Backswing height, X-Factor, pelvis angle and thorax rotation angle were not different between normal shot and fat shot. But we could find a pattern of abrupt pelvic movement and weight shift to target direction just before impact in case of fat shot. In addition fat shot showed time-delayed and small value of pelvis linear velocity pattern to upward during downswing phase as against normal shot.