• Title/Summary/Keyword: external contraction

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Comparison of multifidus and external oblique abdominis activity in standing position according to the contraction patterns of the gluteus maximus

  • Choi, Hyuk-Soon;Lee, Su-Young
    • Physical Therapy Rehabilitation Science
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    • v.5 no.1
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    • pp.40-46
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    • 2016
  • Objective: The purpose of this study was to examine the effect on multifidus and external oblique abdominis muscle activation during hip contraction of three types (concentric, isometric, eccentric) in standing position. Design: Cross-sectional study. Methods: Twenty healthy adult men volunteered to participate in this study. Muscle activation was recorded from gluteus maximus, both multifidus, and both external oblique abdominis by surface electromyography (EMG) while holding position in the type of gluteus maximus contraction. EMG values were normalized by maximum muscle contractions (% maximum voluntary isometric contraction). All subjects performed hip extension with three contraction methods. The type of gluteus maximus contraction using Thera-band was composed of concentric contraction (type 1), isometric contraction (type 2), and eccentric contraction (type 3). To measure muscle activation on the gluteus maximus contraction type, each position were maintained for 5 seconds with data collection taken place during middle three seconds. Muscle activation was measured in each position three times. Results: For the results of this study, there was no significant difference within three contraction patterns of the gluteus maximus (concentric, isometric, and eccentric) each both multifidus, both external oblique abdominis, and gluteus maximus. And there was no significant difference among both multifidus, both external oblique abdominis, and gluteus maximus each hip extension contraction type. Conclusions: These findings suggest that specific contraction types of the gluteus maximus does not lead to a more effective activation of the multifidus, external oblique abdominis, and gluteus maximus.

A Study on the Relationship between the Internal and External from Discussions on Li Dongyuan's Differentiation of Internal and External Damage (이동원(李東垣) 내외상변(內外傷辨) 관련 논의들에 나타난 내외(內外) 관계성에 대한 고찰)

  • Eun Seokmin
    • Journal of Korean Medical classics
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    • v.36 no.2
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    • pp.61-75
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    • 2023
  • Objectives : This study aims to examine the multi-layered meanings of Li Dongyuan's concept of 'internal damage' through examining the origins of the 'internal damage' concept together with discussions derived from his 'Differentiation of Internal and External Damage'. Methods : Rather than Li's original works, those done by later doctors who were influenced by Li were thoroughly examined in this study to determine the relationships among internal and external damage, and external contraction. Results : Based on discussions related to the 'differentiation of internal and external damage' following Li, his concept of 'internal damage' could be understood as multi-layered, as it contains both spatial as well as pathogenic meaning. Therefore the meaning behind categorizations of internal and external damage, and internal damage and external contraction could be different. Li's 'internal damage' concept includes not only internal pathogen but elements of external contraction of wind and cold, which seems to have been integrated into the 'Cold Damage Theory' after Zhu Danxi, seemingly having changed the concept of cold damage. Therefore, discussions on the crossing between internal damage and external contraction have on one hand expanded the boundaries of each concept, while on the other hand, have caused confusion between the two at times. Conclusions : The concept of 'internal damage' has been widely accepted due to Li Dongyuan, on which related discussions have been centered. However, the concept was originally multi-layered, naturally leading to various discussions. Future studies should focus on the relationship of 'internal damage' with 'external damage' or 'external contraction', beyond the theories of Li.

Analysis of the stresses induced by magnetic field and cooling in the CICC type superconducting bus-line (CICC 형태의 초전도 버스 선에서 냉각 및 자기장에 의한 응력 해석)

  • Lee, Ho-Jin;Nam, Hyeon-Il;Kim, Gi-Baek;Hong, Gye-Won
    • Progress in Superconductivity and Cryogenics
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    • v.2 no.2
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    • pp.20-25
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    • 2000
  • A CICC type superconducting bus-line electrically connecting a superconducting magnet to a power supply is cooled down to low temperature under the external magnetic field during operation. The thermal contraction during the cooling may be constrained by the supports which are installed to protect the bus-line from Lorenz magnetic forces. This constrained contraction causes thermal stresses in the bus-line to release thermal contraction. The minimum stress conditions in the bus-line may be optimized by controlling the supporting arrangement considering the thermal contraction and the external field. The analytical method to find optimal supports arrangement was suggested by using the beam theory, and numerical calculation using commercial code was performed to verify the suggested analytical optimization method.

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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.

Effects of Conscious Contraction of the Pelvic Floor Muscles during Abdominal Hollowing on the Trunk Muscle (배꼽 넣기 동안 의식적인 골반저근의 수축이 체간 근육에 미치는 영향)

  • Lee, Yun-Sang;Tak, Sa-Jin;Park, Ji-Yu;Choi, Won-Jae;Lee, Seung-Won
    • Journal of the Korean Society of Physical Medicine
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    • v.12 no.4
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    • pp.123-132
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    • 2017
  • PURPOSE: This study aimed to examine the effects of lumbar stabilization exercise during abdominal hollowing with conscious contraction of the pelvic floor muscles on trunk muscle in healthy twenties subjects. METHODS: The participants were randomly allocated to an experimental group (n=15) and a control group (n=15). The experimental group received lumbar stabilization exercise combined with conscious contraction of the pelvic floor muscles during abdominal hollowing. The control group received lumbar stabilization exercise with abdominal hollowing. Both groups trained with the respective exercise for 30 minutes a day, 3 times a week for 6 weeks. Muscle activation of the external oblique and erector spinae muscles, thickness of the transversus abdominis and multifidus, and contraction holding time of tranversus abdominis were measured before and after exercise. RESULTS: Activations of both the external oblique muscles were significantly decreased, and thickness of both the transversus abdominis and multifidus muscles, and contraction holding time of the transversus abdominis muscle were significantly increased in the experimental group (p<.05). The thickness of the left transversus abdominis and right multifidus muscles, and the contraction holding time of the transversus abdominis muscle significantly increased in the control group (p<.05). On comparing both groups, the activations of both external oblique muscles were significantly reduced and the contraction holding time of the transversus abdominis muscle was significantly increased in the experimental group (p<.05). CONCLUSION: These results suggest that lumbar stabilization exercise by abdominal hollowing and conscious contraction of the pelvic floor muscles is suitable and efficient for healthy twenties subjects.

The Effects of the Contraction Degree of Hip Joint Adductor on Abdominal Muscle Activity during Bilateral Lower Extremity Raising

  • Kim, Min-Kyu;Cho, Yong-Ho;Park, Ji-Won;Choi, Jin-Ho;Ko, Yu-Min
    • The Journal of Korean Physical Therapy
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    • v.28 no.3
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    • pp.217-220
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    • 2016
  • Purpose: This study was to investigate the differences abdominal muscles activities of according to hip adductor contraction levels 20% (mild), 50% (moderate), and 70% (strong) of MVIC on during bilateral lower extremity raising exercise on supine. Methods: The subjects of the study were a total of 39 persons including 23 healthy males and 16 females, who performed bilateral lower extremity raising exercise in 20%, 50%, 70% MVIC hip contraction. Muscle activities were measured by using S-EMG in RA (rectus abdominis), IO (internal oblique), and EO (external oblique). Results: Muscle activity of the internal oblique abdominal muscle and external oblique abdominal muscle, their activities were also greatest with the adductor contraction size at 70% and there was statistically significant difference when compared with the adductor contraction size at 20% and 50% (p<0.05). As for the rectus abdominis muscle according to the size of contraction of the adductor was greatest at 70%, without statistically significant difference (p>0.05). Conclusion: bilateral lower extremity raising with strong hip joint adductor contraction was effective exercise to strengthen abdominal muscles. If subjects could not perform strong hip adductor contraction, moderate contraction is effective abdominal muscle contraction exercise. The contraction size of the adductor is small, weak contraction may trigger middle level contraction and therefore appropriate application of the exercise program of bilateral leg raising may result in great effect as a lumbar stabilization exercise.

Effects of Risering Design and Alloying Element on Formation of Shrinkage Cavity in Ductile Cast Iron (구상흑연주철의 수축결함생성에 미치는 주조방안 및 합금원소의 영향)

  • Yu, Sung-Kon
    • Korean Journal of Materials Research
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    • v.13 no.2
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    • pp.74-80
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    • 2003
  • The effects of risering design and alloying element on the formation of defects such as external depression, primary and secondary shrinkage cavities in ductile cast iron were investigated. Two types of risering design for the cylindrically step-wise specimen, No. 1(progressive solidification) and No. 2(directional solidification) risering designs, were prepared and six different alloy compositions were casted. In the No. 1 risering design, external depression or primary shrinkage cavities due to liquid contraction were observed in all the specimens from SG 10 to SG 60. The defects caused by liquid contraction seemed to be more affected by risering design than alloying elements. The secondary shrinkage cavities were also observed in all the specimens but a swollen surface was not observed in all the castings. The primary shrinkage cavities were located right under the top surface or connected to the top surface, and were characterized by smooth surfaces. On the other hand, the secondary shrinkage cavities were positioned in the thermal center of the specimen steps 3 and 4, and characterized by rough surfaces. In the No. 2 risering design, no external depression or primary shrinkage cavities due to liquid contraction were observed in all the specimens from SG 10 to SG 60. However, the secondary shrinkage cavities were formed in the thermal center of specimens SG 40, 50 and 60. Like the No. 1 risering design, a swollen surface was not observed in all the castings.

Consideration of the Exterior Syndrome Caused by External Pathogen (wind-cold-dampness) (외사(外邪)(풍한습사(風寒濕邪))에 의한 외감표증(外感表證)의 발병기전(發病機轉)에 대한 소고)

  • Lee, Sang-Ryong;Lee, Chang-Hyun;Lee, Kwang-Gye
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.4
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    • pp.409-417
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    • 2012
  • External pathogens such as wind, cold can easily invade the external parts of the body when host's external defense ability is not secure. Herein, we consider the underlying mechanisms against the external contraction at the body surface. During the early period after primary invasion, external defense mechanisms are gradually activated. The classic clinical manifestations are aversion to cold, fever, headache, generalized pain, and nasal congestion. This condition is called by invasion of external pathogen into the body surface. As the disease progress, lung qi is stagnated and thereby up-outward and downward movement action of lung become disturbed. Therefore, when doctor administrate formula to treat the exterior syndrome, doctor must keep in mind not only materia medica, but also underlying mechanisms through which many clinical symptoms appear.

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 External $Ca^{2+}$ ana the Inhibition of Na-pump on the Vanadate-induced Contraction in the Isolated Human and Rat Uterine Smooth Muscle (사람 및 흰쥐의 자궁근에서 Vanadate에 의한 수축에 미치는 외부 Calcium 및 Na-pump억제의 영향)

  • Jung, Jin-Sub;Han, Bok-Ki;Woo, Jae-Suk;Lee, Sang-Ho
    • The Korean Journal of Physiology
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    • v.18 no.2
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    • pp.125-137
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    • 1984
  • The effects of external $Ca^{2+}$ ana the inhibition of Na-pump on vanadate-induced contraction in isolated human and rat uterine smooth muscle were studied and the following results were observed. 1) Vanadate induced contraction in rat uterine muscle and showed maximal contraction at concentration of $5{\times}10^{-4}$M, and the contractile response to vanadate was more sensitive in human than rat uterine muscle. 2) Vanadate-induced contraction was not completely inhibited by $Ca^{2+}$ removal from PSS and the response to $Ca^{2+}$ removal was more sensitive in human than rat uterine muscle. 3) Vanadate-induced contraction decreased with increasing concentration of verapamil, but even in the presence of $3{\times}10^{-5}M$ verapamil which inhibited 100 K-induced contraction completely. about 40% of maximal contraction remained, and its amplitude was similar to that of contraction in $Ca^{2+}$-free solution. 4) Vanadate-induced contraction was increased by the inhibition of Na-pump and this increase also could be observed in the presence of $3{\times}10^{-5}M$ verapamil. 5) After pretreatment with $Ca^{2+}$-free PSS containing ouabain Vanadate-induced contraction was not increased, but the contractile response of these tissues to the addition of external $Ca^{2+}$ was remarkably increased in the presence of vanadate. 6) $3{\times}10^{-5}$M verapamil inhibited vanadate-induced $Ca^{45}$ influx completely, but after pretreatment with ouabain vanadate could induce remarkable $Ca^{45}$ influx even in the presence of verapmil. 7) With increasing the time of pretreatment with ouabain or $K^+$-free solution, the degree of increase in contraction by vanadate was more remarkable. 8) $10^{-4}M$ papaverine stowed a considerable inhibition of the increase in the vanadate-induced contraction by pretreatment with ouabain. 9) Acetylcholine-induced contraction increased with lengthening the duration of Na-pump inhibition even in the presence of verapamil. Considering above results it seems that the uterine muscle of human is more sensitive to vanadate than that of rat, and both internal and external $Ca^{2+}$ is utilized in vanadate·induced contraction. In the case of Na-pump inhibition several smooth muscle contracting agents seems to induce $Ca^{2+}$ influx which is not inhibited by verapamil. This $Ca^{2+}$ influx seems to be inhibited by papaverine and to be associated with membrane potential, although its precise characteristics is not certain.

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