• Title/Summary/Keyword: Contraction Ratio

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The Study of Asymmetrical Contraction of the Lateral Abdominal Muscles in Stroke Patients Using Ultrasound Imaging (초음파 영상을 통한 뇌졸중 환자의 외측복부근 근수축의 비대칭성 연구)

  • Park, Hyun-Ju;Oh, Duck-Won;Shin, Won-Seob
    • Journal of the Korean Society of Physical Medicine
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    • v.7 no.3
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    • pp.319-327
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    • 2012
  • Purpose : This study aimed to identify the asymmetry observed in the rehabilitative ultrasound imaging of lateral abdominal muscle thickness and performance between the affected and unaffected side during the abdominal drawing-in maneuver (ADIM), an exercise used to facilitate activation of selectively TrA to stabilize the trunk prior to limb movement. Methods : The Participants were twenty one patients with post-stroke hemiplegia in this study. Ultrasound imaging was used to measure amount of changes in thickness of the external oblique (EO), internal oblique (IO), transversus abdominis (TrA). A Paired t-test was used to compare relaxed muscle thickness to contracted muscle thickness of all 3 muscles between the affected and unaffected sides. Results : The outcome measures included side to side differences of absolute thickness, contraction ratio among the lateral abdominal muscles. There was no significantly difference in between the affected and unaffected side at rest. But, there was a significantly difference in absolute muscle thickness between the affected and unaffected side of only TrA muscle. Also contraction ratio was a significantly difference between the affected and unaffected TrA muscle. Conclusion : These findings support the asymmetrical activation of TrA muscle during abdominal muscle contraction in patients with post-stroke hemiplegia. Further studies are warranted for confirming this outcome.

Enhancing Shoulder External Rotator Electromyography Activity During Sitting External Rotation Exercise: The Impact of Biofeedback Training

  • Il-young Yu;Min-joo Ko;Jae-seop Oh
    • Physical Therapy Korea
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    • v.30 no.3
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    • pp.237-244
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    • 2023
  • Background: The external rotation (ER) exercise in performed at a 90° abduction of the shoulder joint is an effective to strengthen the infraspinatus. However, failure of the humeral head to control axial rotation during exercise can be increased the posterior deltoid over activity. Biofeedback training is an effective method of promoting motor learning and control it could look forward to activate the infraspinatus selectively by controlling the humeral head during exercise. Objects: The aim of this study was investigated that whether biofeedback for axial rotation was effective to activate selectively the infraspinatus during ER exercise. Methods: The 15 healthy males participated, and all subjects performed both ER exercise in a sitting position with shoulder abducted 90° under conditions with and without axial rotation biofeedback. Exercise was performed in a range of 90° ER, divided into three phases: concentric, isometric, and eccentric. The infraspinatus and posterior deltoid muscle activity were observed using surface electromyography. Results: Both infraspinatus activity (p < 0.01) and infraspinatus to posterior deltoid activity ratio (p = 0.01) were significantly higher with biofeedback however, posterior deltoid activity was significantly lower with biofeedback (p = 0.01). The infraspinatus muscle activity and muscle activity ratio were the highest in the isometric contraction type, and there were significant differences for all contraction types (p < 0.05). Whereas, the posterior deltoid activity was the lowest in the isometric contraction type, and showed a significant difference between isometric and other two contraction types (p < 0.05), but no significant different between concentric and eccentric contraction. Conclusion: Our results indicate that the axial rotation biofeedback during sitting ER exercise might be effective method to activating selective infraspinatus muscle and recommended to enhance the dynamic stability of the shoulder joint.

Effects of Dilatation and Vortex Stretching on Turbulence in One-Dimensional and Axisymmetric Flows (일차 및 축대칭유동에서 밀도변화가 난류에 미치는 영향)

  • Kim Jin-Hwa;Yoo Jung Yul;Kang Shin-Hyoung
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.831-834
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    • 2002
  • An analytic approach is attempted to predict the amplification of turbulence in compressible flows experiencing one-dimensional and axisymmetric bulk dilatation. The variations of vortex radius and vorticity are calculated, and then the amplification of turbulence is obtained from them by tracking three representative vortices. For a one-dimensionally compressed flow, the present analysis slightly underestimates the amplification of velocity fluctuations and turbulent kinetic energy, relative to that of rapid distortion theory in the solenoidal limit. For an axisymmetrically distorted flow, the amplification of velocity fluctuations and turbulent kinetic energy depend not only on the density ratio but also on the ratio of streamwise mean velocities, which represents streamwise vortex contraction/stretching. In all flows considered, the amplification of turbulence is dictated by the mean density ratio. In the axisymmetric flow, streamwise vortex stretching/contraction, however, alters the amplification slightly.

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The Evaluation of Sleeve Appearance on Sleeve Easing Contraction Using Virtual Garment Simulation (가상착의 시뮬레이션을 이용한 소매 오그림량 배분에 따른 외관평가)

  • Oh, Young Soon;Kim, Yeo Sook
    • The Korean Journal of Community Living Science
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    • v.24 no.4
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    • pp.457-469
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    • 2013
  • The purpose of this study is to quantitatively analyze the impacts of the distribution of easing contraction of the sleeve on the external appearance of bodice and sleeve through virtual clothing simulation. Virtual clothing is conducted by differentiating the sleeve easing in accordance with the experimental condition of bodice and sleeve that are followed by draping. And then the evaluation is carried out. As a result of an analysis of the similarity between the virtual garment and the actual clothing, the whole external appearance of the bodice and sleeve was expressed similarly. The external appearance according to the distribution of easing contraction got better as the easing contraction of sleeve was concentrated on sleeve cap in front while the appearance was better at the back as it was more gently distributed than in the front. In a comparison of armhole form, the clothing of which the top of it was most similar to S0 was S4 in which the gap between the armhole and the arm was the least and the front and rear silhouette fell relatively well. In a comparison between the position of bust circumference line and that of the sleeve base line, the front of the sleeve matched the bust circumference line as the easing contraction was distributed close to the center of the sleeve cap while in the back, the sleeve base line and the bust circumference line matched when some easing contraction ratio was added close to the armpit point. The cross section figures of garment space of the shoulder, the margin was evenly distributed in S4 or S5 with differing distributions of easing contraction in the front and the back. This study is significant in that it supplies the objective baseline data which makes a novice more able to make a good external appearance of the sleeve.

Determination of Ratios of Natural Ingredients for Loess(Hwangtoh) as Environmental-Friendly materials (친환경 건축자재로서 황토마감재 개발을 위한 천연혼화재 비율설정에 관한 연구)

  • Lee, Tae-Goo
    • KIEAE Journal
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    • v.6 no.2
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    • pp.51-57
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    • 2006
  • With people's awareness of environment-friendly buildings recently increasing, there is a need to develop environment-friendly construction materials to reduce indoorair pollution levels. Thus, efforts to develop loess finishing materials that can replace the finishing materials currently being used (e.g., gypsum boards and chemical products) are underway. An analysis of the characteristics of domestic loess products,however, revealed that the cracks on loess products can be lessened and their strength can be improved by adding chemical ingredients to them. Thus, this research sought to use 100% natural materials and to develop loess finishing materials. In the experiments that were conducted in this study, appropriate mixture ratios of loess and sand/silica sand were found, and cracks and contraction ratio changes in samples were analyzed by differentiating the ratios of natural ingredients, such as lime, fine jute threads, gypsum, and jute cuttings. Loess'particle size distribution was found to have a high correlation with loess decoration, and it was discovered that the mixture of lime and fine chute threads could improve the contraction ratio. Through this study, which made use of natural ingredients, environment-friendly construction materials that can exercise the original function of loess were developed.

Effect of Magnesium Ion on the Contractility of the Isolated Rat Uterine Smooth Muscle (마그네슘 이온이 적출한 흰쥐 자궁근의 수축성에 미치는 효과)

  • Chang, Sang-Ho;Hwang, Sang-Ik;Sung, Ho-Kyung
    • The Korean Journal of Physiology
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    • v.20 no.2
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    • pp.199-208
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    • 1986
  • The effects of $Mg^{++}$ upon the spontaneous contraction activated by 1 IU/l oxytocin were studied in the isolated rat uterine muscle. Longitudinal muscle strips u·ere prepared from the rat uteri at the estrous stage. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) In the uterine strips contracting spontaneously, as $Mg^{++}$ concentration increased in the Tyrode solution the amplitude of peak tension decreased in all the experimental solutions containing the various concentrations of $Ca^{++}\;(0.5{\sim}4 mM)$. And the amplitude of peak tension increased in inverse proportion to the $[Mg^{++}]/[Ca^{++}]\; ratio$. It is suggested that the tension-lowering effect of $Mg^{++}$ would be developed through decreasing intracellular ionized free calcium ion concentration by uncertain mechanism. 2) The frequency of the uterine contraction activated by oxytocin increased as the $[Mg^{++}]/[Ca^{++}]\;ratio$ ratio increased up to 1/2, but the frequency decreased above this ratio. It is speculated that $Mg^{++}$ would influence the excitability control action of $Ca^{++}$.

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Analytical Study on Compressible Flour through Abrupt Enlargement and Contraction (급축소/확대관을 지나는 압축성 유동의 해석적 연구)

  • 김희동;김태호;서태원
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1997.04a
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    • pp.235-244
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    • 1997
  • The empirical factor and reaction force based on published data were involved to investigate compressible flows through sudden enlargement and sudden contraction passages. Analytical solutions of engineering interest were obtained from one-dimensional steady compressible gas dynamic equations. The effects of compressibility, cross-sectional area ratio, and inlet Mach number on the air flows were discussed with regards to the total pressure loss and flow choking. The present results provide available information necessary ta design the compressible pipe flow systems.

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Effects of Irradiation on the Muscle Activity Around an Amputation Site During Proprioceptive Neuromuscular Facilitation Pattern Exercise for Upper Extremity and Scapular Exercise on the Non-Amputated Part -A Case Study- (비 절단부에 적용한 PNF 상지 패턴과 견갑골 움직임에 의한 방산이 절단부 주변 근육 활성도에 미치는 영향 -단일 사례연구-)

  • Choi, Su-Hong;Rhee, Min-Hyung;Ha, Kyung-Jin;Lee, Sang-Yeol
    • PNF and Movement
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    • v.17 no.1
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    • pp.11-18
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    • 2019
  • Purpose: This study verifies the muscle activity around the amputation site during proprioceptive neuromuscular facilitation (PNF) pattern exercise for the upper extremities on the non-amputated part in upper extremity amputees and provides basic data on effective exercise around an amputation site. Methods: Manual resistance was applied to the PNF upper extremity pattern of the non-amputated part to generate muscle activity around the amputation site. The resistance was adjusted to an intensity that could cause maximal isometric contraction. The muscle activity of the amputation site and the non-amputated part was measured using a surface electromyogram for the upper trapezius, middle trapezius, infraspinatus, serratus anterior, and pectoralis major. Results: During the scapular exercise in the painless range, the amputated side showed significantly lower muscle activity and a lower muscle contraction ratio compared with the non-amputated side. During the PNF pattern exercise in the painless range, the amputated side showed lower muscle activity and a lower muscle contraction ratio compared with the non-amputated side. When the direct scapular exercise of the amputated side was compared with the PNF pattern exercise of the non-amputated side, their muscle contraction ratios were similar. Conclusion: This study confirmed the effectiveness of the PNF pattern exercise of the non-amputated part as a way to indirectly train the injured site with no pain for rehabilitation of patients with serious body injuries, such as amputation. It is necessary to develop effective exercise programs for the rehabilitation of the amputation site based on the results of this study.

Current Transformer Using Epoxy (에폭시를 사용한 변류기)

  • Park, Chul-Woong;Kim, Hyang-Kon
    • Proceedings of the KIEE Conference
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    • 2008.09a
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    • pp.199-202
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    • 2008
  • In this paper, we studied a accuracy for CT using elastic epoxy. According to industry development, the quality where also the electric material is various is demanded. Insulation material is widely used because epoxy is superior to electrical and mechanical property. Until now, the possibility where the crack will occur is high because epoxy used to electrical products had high hardness. If thermal expansion is different of two material, contraction of epoxy heavily transformed turns ratio of CT Elastic epoxy absorbed in expansion and contraction of substance material by temperature. So we could design more exacted CT We had elastic test of elastic epoxy and made CT using elastic epoxy. At the result, We obtained turns ratio of within 4% superior to existing CT.

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Conceptual Study of a Low-Speed Wind Tunnel for Performance Test of Wind Turbine (풍력터빈 성능시험을 위한 저속풍동 개념연구)

  • Kang, Seung-Hee
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.19 no.4
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    • pp.24-29
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    • 2011
  • Conceptual study of an open-circuit type low-speed wind tunnel for performance test of wind turbine blade and airfoil is conducted. The tunnel is constituted of a settling chamber, a contraction, closed test section, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The contraction ratio is 9 to 1 and maximum speed in the test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine and airfoil.