케틀벨 스윙 시 무게와 구간별 동작에 따른 몸통 및 엉덩이 근육 활성도 비교

이정노,신윤아 한국코칭능력개발원 2023 코칭능력개발지 Vol.25 No.5

이 연구는 케틀벨 스윙 시 각 구간별 몸통 및 엉덩이 근육의 활성도 차이를 알아보고, 케틀벨 스윙 시 구간별 무게에 따른 근활성도에 차이가 있는지 알아보고자 실시되었다. 연구대상은 케틀벨 지도자 자격을 소지한 숙련자 13명으로 선정하였다. 측정자의 우세측큰볼기근, 허리부 척주세움근, 배바깥빗근, 배곧은근에 전극을 부착하여 몸통 및 엉덩이 근육의 활성도를 측정하였다. 케틀벨 스윙은 ‘스윙 전 구간, 가속 구간, 스윙 구간, 스윙 마지막 구간, 복귀 구간’ 5구간으로 구분하여 근육의 활성도를 측정하였다. 본 연구에서몸통 및 엉덩이 근육의 활성도를 케틀벨 스윙의 각 구간과 무게에 따라서 근육 별로 분석한 결과, 배곧은근과 배바깥빗근 및 큰볼기근의 활성도는 구간별 차이가 나타났으며, 스윙 마지막 구간이 다른 모든 구간보다 유의하게 높게 나타났다. 척주세움근의 활성도는구간별 차이가 나타났으며, 가속 구간과 스윙 구간이 스윙 전 구간과 스윙 마지막 구간, 복귀 구간보다 유의하게 높게 나타났다. 따라서, 케틀벨 스윙의 구간에 따른 활성도 차이는 스윙 초기에서 중간단계인 스윙 전, 가속 및 스윙 구간에서는 척주 정렬의 안정화 유지를 위해 척주세움근이 가장 높게 나타났고, 스윙 중간단계 이후에는 엉덩관절의 폄으로 인한 큰볼기근의 활성도가 점점 높아졌으며, 스윙의 마지막 부분에서는 큰볼기근의 가장 높은 활성도를 나타냈으며 몸통의 정렬 유지와 안정화를 위한 강한 복부의 수축으로인해 배곧은근과 배바깥빗근의 활성도가 함께 높아지는 것으로 나타났다. 복귀 구간인 다운-스윙에서는 큰볼기근의 활성도가 다른 근육들에 비하여 높은 상태를 유지하였다. 이상의 결과를 종합해보면, 케틀벨 스윙 운동 시 이러한 근활성도의 동원과 역할을 인지하면서 스윙 동작을 연습하도록 지도하는 것이 부정확한 스윙 동작을 예방하여 부상의 위험을 줄이고, 정확하고 효과적인 스윙 방법을 숙달하는데 있어서 더 효율적일 것으로 생각된다. This study was conducted to find out the difference in activity of trunk and hip muscles according to phase during kettlebell swing, and to find out whether there was a difference in muscle activity according to the weight during kettlebell swing. The subjects of the study were selected as 13 skilled persons with kettlebell instructor qualifications. The activities of trunk and hip muscles were measured by attaching electrodes to the gluteus maximus (GM) muscle, the lumbar erector spinae (ES) muscle, the external oblique (EO) muscle, and the rectus abdominis (RA) muscle on the dominant side of the participates. Muscle Activity was measured kettlebell swing is divided into 5 phases: pre-swing phase, acceleration phase, swing phase, terminal swing phase, and return phase. In this study, as a result of analyzing the activity of the trunk and hip muscles according to weight and phases during the kettlebell swing, the activities of the RA, EO, and GM muscle showed a difference according to phase, and the last phase of the swing showed significantly higher than all phases. There was a difference in the activity of the ES muscle according to phase, and the acceleration and swing phases were significantly higher than the pre-swing, the last of swing, and the return phases. Therefore, the activity difference according to the kettlebell swing phase was the highest in the ES muscle for stabilizing the alignment of the spine in the pre-swing, acceleration and swing phases, which are the initial to intermediate stages of the swing. After the mid-swing phase, the activity of the GM muscle gradually increased due to the extension of the hip joint. At the end of the swing, the GM muscle showed the highest activity, and the activities of the RA and EO muscles increased together due to strong abdominal contraction to maintain alignment and stabilization of the trunk. In the down-swing, which is the return section, the activity of the GM muscle remained higher than that of other muscles. Taken together, it is suggested that teaching to recognize the mobilization and role of these muscle activities during kettlebell swing exercise during practice swing movements will be more effective in preventing inaccurate swing movements, reducing the risk of injury, and mastering accurate and effective swing methods.

Differences in Lower Extremity Electromyographic Responses Based on Foot Position and Swing Phase in Golf Driver Swings

지영진,정환종,김병관 한국인터넷방송통신학회 2023 International journal of advanced smart convergenc Vol.12 No.4

The purpose of this study was to investigate the muscle activity of the lower extremity during driver swing in three-foot positions (Feet Open Stance, Feet Straight Stance, Lead Foot Open Stance). The electromyograms of gastrocnemius, tibialis anterior, and vastus lateralis during swing were measured and analyzed in three sections (take away - back swing, back swing - down swing, and down swing - follow swing). There was no significant difference in muscle activity according to foot position. Muscle activity according to phase was significantly higher in right gastrocnemius and tibialis anterior, and the left and right vastus lateralis in down swing - follow swing. In conclusion, the difference in muscle activity according to foot position is insignificant, and it is considered that the muscle activity to maintain the balance of the body increases toward the end of swing.

수직점프에서 팔 스윙형태가 점프높이에 미치는 영향

신제민 한국사회체육학회 2023 한국사회체육학회지 Vol.- No.91

Purpose: The purpose of this study is to analyze the effect of the arm swing direction on the jump height during a vertical jump and to suggest an efficient arm swing pattern (ASP). Method: Ten infrared cameras including two force plates were used to analyze the jumping motion. The subjects of the research were 10 male university students. The experiment task was to jump as high as possible by swinging from front to back, from back to front, and fixing their arms without swinging. A 3D cinematography was performed, and biomechanical variables were analyzed by dividing the entire motion period into a braking phase and an accelerating phase to efficiently compare changes at ASP. Results: Among the three arm swings, the jump height and the vertical velocity increased the most just before the take-off when the arm swung from back to front, and the jump height tended to increase with the magnitude of the impulse. However, the duration of the braking and accelerating phases, joint angle, torque, and power of the lower extremity did not show any characteristic results depending on the ASP. The work done by the lower extremity joint also did not show a significant difference in the change of the ASP. Conclusion: The swing from back to front is the most efficient ASP because it increases jump height and vertical velocity just before take-off. However, other biomechanical variables do not show a clear difference even when the ASP is changed. In contrast to the hip and ankle joints, the knee joint continued to exhibit eccentric contraction even during the accelerating phase, and this characteristic is evident when the arm is fixed. The decrease in eccentric contraction of the knee joint during the arm swing in the accelerating phase can be positive in that it suppresses energy absorption in the vertical jump.

Effect of Rehabilitation Exercise for Golfers on the X-factor and Ground Reaction Force according to Phase of the Golf Swing

윤정규,조병윤 국제물리치료연구학회 2019 Journal of International Academy of Physical Ther Vol.10 No.1

Background: Despite frequent shoulder injuries of rotator cuff muscle of golfers by the result of overuse and poor swing mechanics, there is little research on shoulder specific rehabilitation exercises for injured rotator cuff muscle and golf swing Objective: To examined the effect of rehabilitation exercise for golfers on the X factor and ground reaction force (GRF) according to phase of the golf swing. Design: Crossover study Methods: The participants were 13 amateur golfers selected for a 4 week rehabilitation exercise for golfers. A rehabilitation exercise for golfers consisting of 5 steps and 4 items (sleeper stretch, full side plank, push up to plank, high plank knee unders) were applied to all participants. A three dimensional motion analyzer and force platform (SMART-E, BTS, Italy) were used to measure the X factor (angle between shoulder and pelvis at top of back swing) and GRF according to phase of the golf swing. All dependent variables were measured before and after exercise. The collected data was analyzed using the paired t test and SPSS 21.0. Results: The GRF had a statistically significant increase in the impact phase and ratio impact/weight after rehabilitation exercise for golfers (p<.05). The Xfactor, GRF in top of back swing and finish were no significant differences between before and after exercise (p>.05). Conclusions: These results suggested that rehabilitation exercise for golfers was effective for increasing GRF in the impact phase and ratio impact/weight for amateur golfer.

Effect of Rehabilitation Exercise for Golfers on the X-factor and Ground Reaction Force according to Phase of the Golf Swing

Junggyu yoon,Byungyun Cho 국제물리치료연구학회 2019 Journal of International Academy of Physical Ther Vol.10 No.1

Background: Despite frequent shoulder injuries of rotator cuff muscle of golfers by the result of overuse and poor swing mechanics, there is little research on shoulder specific rehabilitation exercises for injured rotator cuff muscle and golf swing Objective: To examined the effect of rehabilitation exercise for golfers on the X factor and ground reaction force (GRF) according to phase of the golf swing. Design: Crossover study Methods: The participants were 13 amateur golfers selected for a 4 week rehabilitation exercise for golfers. A rehabilitation exercise for golfers consisting of 5 steps and 4 items (sleeper stretch, full side plank, push up to plank, high plank knee unders) were applied to all participants. A three dimensional motion analyzer and force platform (SMART-E, BTS, Italy) were used to measure the X factor (angle between shoulder and pelvis at top of back swing) and GRF according to phase of the golf swing. All dependent variables were measured before and after exercise. The collected data was analyzed using the paired t test and SPSS 21.0. Results: The GRF had a statistically significant increase in the impact phase and ratio impact/weight after rehabilitation exercise for golfers (p<.05). The Xfactor, GRF in top of back swing and finish were no significant differences between before and after exercise (p>.05). Conclusions: These results suggested that rehabilitation exercise for golfers was effective for increasing GRF in the impact phase and ratio impact/weight for amateur golfer.

Effect of Rehabilitation Exercise for Golfers on the X-factor and Ground Reaction Force according to Phase of the Golf Swing

yoon, Junggyu,Cho, Byungyun International Academy of Physical Therapy Research 2019 Journal of International Academy of Physical Ther Vol.10 No.1

Background: Despite frequent shoulder injuries of rotator cuff muscle of golfers by the result of overuse and poor swing mechanics, there is little research on shoulder specific rehabilitation exercises for injured rotator cuff muscle and golf swing Objective: To examined the effect of rehabilitation exercise for golfers on the X factor and ground reaction force (GRF) according to phase of the golf swing. Design: Crossover study Methods: The participants were 13 amateur golfers selected for a 4 week rehabilitation exercise for golfers. A rehabilitation exercise for golfers consisting of 5 steps and 4 items (sleeper stretch, full side plank, push up to plank, high plank knee unders) were applied to all participants. A three dimensional motion analyzer and force platform (SMART-E, BTS, Italy) were used to measure the X factor (angle between shoulder and pelvis at top of back swing) and GRF according to phase of the golf swing. All dependent variables were measured before and after exercise. The collected data was analyzed using the paired t test and SPSS 21.0. Results: The GRF had a statistically significant increase in the impact phase and ratio impact/weight after rehabilitation exercise for golfers (p<.05). The X-factor, GRF in top of back swing and finish were no significant differences between before and after exercise (p>.05). Conclusions: These results suggested that rehabilitation exercise for golfers was effective for increasing GRF in the impact phase and ratio impact/weight for amateur golfer.

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.

입유각기의 전환이 가능한 기계식 유압 대퇴의지 개발 및 평가

박진국(J. K. Park),정성윤(S. Y. Jung),권칠용(C. Y. Kwon),박세훈(S. H. Park),신현준(H. J. Shin) 한국재활복지공학회 2021 재활복지공학회논문지 Vol.15 No.1

최근의 대퇴절단환자용 유압의지는 입각기 단계의 체중부하에 따른 무릎굴곡에 대한 안정성을 제공하고 유각기 단계의 자연스러운 무릎 굴곡을 제공하기 위하여 무릎 굴곡 저항을 실시간으로 조절해 주는 가변댐핑형 방식을 적용하고 있다. 가변 댐핑형 대퇴의지는 전자식과 기계식이 있으며, 전자식은 센서 및 전동노즐을 통한 유체저항력의 빠른 전환이 용이하나 배터리를 사용하기 때문에 사용시간의 문제를 갖고 있다. 기계식의 경우 단순 브레이크 기능을 가진 제품이 주로 개발되고 있지만, 유압-기구적인 메카니즘의 개선을 통해 기계식으로도 사용시간의 제한이 없는 가변 댐핑형 의지를 개발하는 것이 가능하다. 본 연구에서는 유압-기구 제어방식의 대퇴의지 개발에 있어서 보행 주기 동안 입각기에서 유각기 전환이 가능한 대퇴의지를 분석하여 시제품을 제작하였으며, 제작된 유압실린더의 노즐조절 및 속도에 따른 기능별 유체 댐핑 특성을 측정하였고, 제품성을 위한 유압실린더의 실링 내구성 및 정적 내구성 시험을 수행하였다. 또한 제작된 대퇴의지의 기능 검증을 위하여 단기적인 임상보행을 통하여 안정성을 확인하였다. 본 연구를 통해 개발된 기계식 유압 대퇴의지는 추후 장기적인 내구성이 확보된다면 배터리가 필요한 전자식 MPK 의지의 기능을 대체할 수 있을 것이다. Recently commercial hydraulic prosthetic knee have been applied a method of adjusting knee flexion resistance in real time in order to maintain stability against knee flexion according to weight load in stance phase and to provide natural knee flexion in the swing phase phase. These variable damping prosthetic knee are divided into electronic and mechanical types. The electronic type has the advantage of being able to quickly change the fluid resistance through a sensor and an electric nozzle, but there is a problem that the use time is limited due to the battery. In the case of the mechanical type, if the hydraulic mechanism is improved, it can be developed so that the use time is not limited while implementing functions similar to the electronic type. In this study, we developed a knee prosthesis capable of mechanically switching from stance phase to swing phase during the gait cycle. The fluid damping characteristics for each function according to nozzle control and speed of the developed hydraulic cylinder were measured, and sealing durability and static durability tests of the hydraulic cylinder for productability were performed. In addition, a simple clinical trial was performed to verify the feasibility of the developed knee prosthesis. The hydraulic knee prosthesis developed through this study is expected to be able to replace the electronic MPK knee prosthesis that requires a battery if long-term durability is ensured.

자연과학편 : 이단 평행봉 몸 펴 뒤 공중 2회전 돌아내리기 동작의 운동학적 요인 분석

이연종(YeonJongLee),이순호(SoonHoLee),강기철(KiChulKang) 한국체육학회 2006 한국체육학회지 Vol.45 No.3

이단평행봉의 몸 펴 뒤 공중 2회전 돌아내리기 동작은 C난도에 속하며 다음 고 난도 기술을 수행할 수 있는 기초에 되는 기술이다. 따라서 본 연구는 3명의 국가대표 선수를 대상으로 좌우 대칭으로 동작이 수행하는 이단 평행봉 몸 펴 뒤 공중 2회전 돌아내리기 동작의 운동학적 분석을 통하여 선수들의 기술동작의 특성을 규명하고 보다 나은 내리기 동작 기술을 모색하고자 하는데 목적이 있으며, 이러한 연구결과를 통해 훈련현장에서 선수들의 경기력 향상을 위해 활용할 수 있는 기초 자료를 제공하고자 한다. 이에 삼차원 동작 분석을 통해서 현 여자 국가대표 선수를 대상으로 몸 펴 뒤 공중 2회전 돌아내리기 기술을 운동학적으로 분석하였다. 동작 분석 결과, 현 여자 국가대표 선수들이 정확하게 몸 펴 뒤 공중 2회전 내리기 기술을 수행하기 위해서는 높은 수직 속도와 함께 충분한 연기 시간을 보유할 수 있는 노력을 통해 안정적인 공중동작과 착지가 이루어 질 수 있을 것이며 특히 높은 연기점수를 얻기 위해서도 선수들이 공중 연기를 할 때 팔 분절을 동체에 가깝게 하여 회전력을 증가 시키는 연습이 필요한 것으로 나타났다. The purpose of this study is to investigate the kinematical analysis of double somersault backward straight dismount motion on the even bar using 2-dimensional cinematographic analysis. After analyzing 3 nationally ranked female gymnasts, the following conclusions were drawn: 1. S3 showed the shortest performance time in airborne phase. 2. S1 showed the longest horizontal and vertical displacement in downward swing phase, but S3 showed the longest horizontal displacement and the shortest vertical displacement in upward and airborne phase. 3. It showed the faster vertical velocity in S1 and the slower horizontal velocity in S2 and S3 during downward and airborne phase. 4. S1 performed closely the upper body, but S2 showed the bending position at the airborne phase during performing the double somersault backward straight dismount motion. 5. S1 released the bar with the highest shoulder joint angular velocity, after that showed the highest hip joint angular velocity during airborne phase. But S3 showed the lower in shoulder and hip joint angular velocity than any other players.

Swing and Phase-Noise Enhanced VCO With Capacitive-Division Dynamic-Threshold MOS

Chang-Hun Lee,Changwoo Lim,Tae-Yeoul Yun IEEE 2016 IEEE microwave and wireless components letters Vol.26 No.3

<P>This letter presents a swing and phase-noise enhanced dynamic-threshold voltage controlled oscillator (VCO) using a capacitive division technique. This technique prevents forward biasing of the pn-junction between the body and source when the output swing increases, which results in low phase noise. The proposed VCO shows phase noise of -122.0 dBc/Hz at a 1MHz offset frequency at 2.31 GHz and a figure of merit of -192.7 dBc/Hz while consuming 0.46 mW from a 0.38-V supply voltage. It is implemented using a 0.11 mu m CMOS process with a chip area of 0.96 mm(2).</P>