• 한국운동역학회지
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• 제12권2호
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• pp.77-90
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• 2002

본 연구는 4년 이상의 경력을 가진 스포츠 에어로빅스 대표선수 4명을 대상으로 Straddle jump to push up 동작의 운동학적 분석을 통해 점프와 착지 동작에 대한 정확한 동작을 이해하고 나아가 지도자의 효율적인 지도에 필요한 정확한 동작의 진단과 평가에 도움을 주며, 그 기초자료를 제공하는 데 목적이 있다. 비디오 카메라 2대를 사용하여 촬영하였고, 카메라의 속도는 60frame/sec.로 하였으며, 분석을 위한 운동학적 변인들은 신체중심 높이의 변위, 좌 우 어깨관절 각 변위, 좌 우 주관절 각 변위, 좌 우 고관절 각 변위, 좌 우 슬관절 각 변위, 좌 우 발끝의 속도이며, 각각 개인별 3회씩 수행하여 다음과 같은 결론을 얻었다. 국면별 신체중심 높이의 변위는 event 1, 4, 5($79.05{\pm}9.07,\;46.41{\pm}3.65,\;18.66{\pm}0.54cm$)에서 낮은 신체중심의 높이를 나타냈으며, event 2, 3($120.80{\pm}6.13,\;148.12{\pm}9.19cm$)에서는 높은 신체중심 높이를 나타냈다. 이상을 종합해 볼 때 스포츠 에어로빅스의 Straddle Jump to Push up 동작, 즉 점프동작은 파워를 나타내는 중요한 동작이므로 충분한 유연성과 순발력이 무엇보다도 중요한 요인이라는 결론을 얻었으며, 단순한 근육의 강화가 아닌 특정 파워와 힘의 발달, 각각의 신체분절들의 효율적인 통합이 이루어지도록 훈련시키는 것이 중요하다고 사료된다.

• 월간 기계설비
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• 통권93호
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• pp.52-59
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• 1998

• The Journal of Korean Physical Therapy
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• 제28권2호
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• pp.106-111
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• 2016

Purpose: The aim of this study is to determine the effect of glenohumeral (GH) rotation position in modified knee push-up plus exercise (MKPUP) by examining the surface electromyography (EMG) amplitude in serratus anterior (SA), pectoralis major (PM), and upper trapezius (UTz) and the activity ratio of each muscle. Methods: A total of 22 healthy subjects volunteered for the study. Each subject performed the MKPUP at $0^{\circ}$, $45^{\circ}$, and $90^{\circ}$ of GH joint internal rotation. EMG of the SA and PM, UTz was compared between GH rotation positions and each muscle activity ratio. EMG was used to measure the muscle activity in terms of ratios to maximal voluntary isometric contraction (MVIC). Results: The difference in EMG activity during the exercise in three GH joint internal rotation positions was observed with the SA and the PM. The greater the GH joint internal rotation angle was, the lower the activity of the PM. In contrast, the SA showed higher activity. However, the activity of UT was similar under all conditions. The ratio of the SA and the PM was considerably greater at $90^{\circ}$ GH joint internal rotation than at $0^{\circ}$ and $45^{\circ}$. Conclusion: When excessive activation of the PM or imbalanced activation between the PM and the SA occurs, the MKPUP exercise is most effective at $90^{\circ}$ of GH joint internal rotation. Use of this position would be a beneficial strategy for selective strengthening of the SA and minimizing PM activation.

• 한국전문물리치료학회지
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• 제24권4호
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• pp.29-37
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• 2017

Background: The serratus anterior (SA) muscle is one of the important muscles in the upward rotation of the scapula when the arm is raised. Insufficient muscle activity of the SA can cause deformation of the shoulder rhythm resulting in shoulder pathology. Objects: This study intends to compare SA and upper trapezius (UT) activity during the conventional wall-slide and push-up plus exercises for SA muscle strengthening and the scapular upward rotation (SUR) exercise. Methods: A total of 30 subjects participated in this study, and we measured the muscle activity of the SA and UT muscles during the wall-slide, push-up plus and SUR exercises. The one-way repeated ANOVA was used to compare SA and UT muscle activities during the 3 exercises. Results: During the SUR exercise, SA muscle activity was 79.88% maximum voluntary isometric contraction (MVIC), which was significantly higher than its activity during the other 2 exercises. The UT muscle activity was 47.53 %MVIC during the SUR exercise, indicating a significantly higher UT muscle activity than during the other 2 exercises. Conclusion: These findings suggest that the SUR exercise can maximize SA muscle activity to strengthen the SA while keeping UT muscle activity at an appropriate level.

• 한국전문물리치료학회지
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• 제25권3호
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• pp.1-11
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• 2018

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

• 한국전문물리치료학회지
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• 제31권1호
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• pp.55-62
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• 2024

Background: The serratus anterior (SA) is a muscle that performs protraction of the scapulothoracic joint and plays a role in stabilizing the scapula. Imbalances or weaknesses in SA activation are associated with a variety of shoulder dysfunctions, making selective SA strengthening important for rehabilitation. Objects: We aimed to compare the muscle activation of the pectoralis major (PM), SA, external oblique (EO), and internal oblique (IO) during the push-up plus (PUP) exercise with isometric hip adduction (HA) and abdominal drawing-in maneuver (ADIM). Methods: Nineteen healthy male participants performed three PUP exercises: standard PUP, PUP with ADIM, and PUP with HA. Surface electromyography was used to measure and analyze the muscle activity for PM, SA, EO, and IO. Results: PUP with HA showed the lowest PM activity and highest SA activity, and no significant difference was observed between PUP and PUP with ADIM. PUP with ADIM showed significantly the highest EO and IO activity, followed by PUP with HA and PUP. Additionally, PUP with HA showed the lowest PM/SA ratio, and no significant difference was noted between PUP and PUP with ADIM. Conclusion: PUP with HA was able to show high SA muscle activity while reducing PM muscle activity. In addition, PUP with HA can lead to higher EO and IO muscle activity than standard PUP. This exercise could be used as a practical exercise method to selectively strengthen SA and improve scapular muscle stability during early shoulder rehabilitation.

• 전력전자학회논문지
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• 제10권6호
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• pp.592-597
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• 2005

푸시 풀 포워드 컨버터는 넓은 입력범위에서 저전압 대전류 특성이 좋고 싱글 EI-EE 코어에 출력 인덕터와 변압기 그리고 입력 필터 등 모든 자성소자들을 포함시킴으로써 집적화할 수 있다. 회로의 여러 변수들에 대한 효율 비교를 통해서 집적화된 싱글 코어 푸시 풀 포워드 컨버터에 대해 고찰하였다. 푸시 풀 포워드 컨버터의 변압기는 Nicera사의 5M FEE 18/8/10C와 NC-2H FEI32/8/10C 코어를 이용하였다. 컨버터의 정격은 입력 전압 $36\~72V$이며 출력은 3.3V, 30A이다. NC-2H FEI32/8/10C코어를 사용하였을 경우 스위칭 주파수가 200kHz이고 부하가 11A일 때 $83.5\%$의 최고 효율이 측정되었다. 전부하(full load)시의 효율은 $76.4\%$, 반부하(half load)일 경우에는 $82.95\%$의 효율이 각각 측정 됐다.

• Advances in Computational Design
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• 제3권1호
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• pp.17-34
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• 2018

Tall buildings are categorized as important structures because of the large number of occupants and high construction costs. The choice of competent lateral load resisting systems in tall buildings is of crucial importance. Bracing systems have long been an economic and effective method for resisting lateral loads in steel structures. However, there are some potential adverse aspects to bracing systems such as the limitations they inflict on architectural plans, uplift forces and poor performances in compression. in order to eliminate the mentioned problems and for cost optimization, in this paper, six 20-story steel buildings and frames with different types of bracing, i.e., conventional, mega-scale and buckling-restrained bracing (BRB) were analyzed. Linear and modal push-over analyses were carried out. The results pointed out that Mega-Scale Bracing (MSB) system has significant superiority over the conventional bracing type. The MSB system is 25% more economic. Some other advantages of MSB include: up to 63% less drift ratio, up to 38% better performance in lateral displacement, up to 100% stiffer stories, and about 50% smaller uplift forces. Moreover, MSB equipped with BRB attests even a better seismic behavior in the aforementioned parameters.

• 산업경영시스템학회지
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• 제28권3호
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• pp.75-86
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• 2005

To investigate the fatigue characteristic of upper limbs, this study analyzed RMS(root mean square) and MPF(mean power frequency) value between initial and terminal stages of each experiment condition. And the effect of intermittent endurance time was evaluated using the Borg's CR10 value that was measured for the parts of upper limb. According to the results of ANOVA on RMS value, there were significant difference on the %MVC about push, pull, and down force exertion. Particularly the ANOVA of up force exertion was significant difference on shoulder flexion, elbow flexion and rest time as well as %MVC. The results of ANOVA for MPF value were significant difference on the %MVC in regard of the push and up force exertion. In case of up force exertion, MPF value tended to shift low frequency at all of the experiment conditions. According to the analysis of duty cycle, RMS value considerably increased over 50% duty cycle and as the %MVC increased, the duty cycle affected the increase of RMS value. MPF value for up and down force exertion decreased at 33%, 50% and 67% duty cycle for all of %MVC. Borg CR10 value of hand and forearm were below the 3-point to the 40% of endurance time at 30%MVC and to the 20% of endurance time at 50%MVC with the exception of up force exertion. But Borg CR10 values of upper arm and shoulder at up force exertion were more than 3-point to the 20% of endurance time at 30%MVC and in the start point of endurance time at 50%MVC.

• 한국응용곤충학회지
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• 제58권3호
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• pp.209-218
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• 2019

본 연구는 시설토마토 재배지에서 push-pull 전략을 이용해 담배가루이와 천적곤충의 행동을 제어함으로써 담배가루이(Bemisia tabaci)를 친환경적으로 방제하기 위한 기술을 개발하고자 수행하였다. 담배가루이는 노란색에 유인율이 가장 높았으며, 520 nm의 광원에는 유인반응을 복합광원인 450 + 660 nm의 광원에는 회피반응을 보였다. 천적곤충인 담배장님노린재(Cyrtopeltis tenuis)와 미끌애꽃노린재(Orius laevigatus)는 모두 520 nm의 광원에 가장 높은 유인반응을 보였다. 휘발성 물질로는 ocimene과 carvacrol에 대해 기피반응을, methyl isonicotinate에는 유인반응을 보였다. 토마토 온실에 메밀을 투입하였을 경우 천적곤충인 담배장님노린재의 밀도는 무처리 대비 15일간 약 16배로 높게 유지되었다. Push-pull 세부전략들을 종합 처리한 결과, 처리 50일 경과 후 담배가루이의 트랩당 밀도는 무처리 대비 3배 이상 낮게 나타났으며, 이에 따른 시기별 방제효과는 시간이 경과함에 따라 증가하는 경향을 보인 가운데 최고 68.7%였다.