• Title/Summary/Keyword: Isometric Contraction

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Vasorelaxing Effect by Protopanaxatriol and Protopanaxadiol of Panax ginseng in the Pig Coronary Artery (돼지 관상동맥에서 고려인삼의 Protopanaxatriol과 Protopanaxadiol의 혈관이완 효과)

  • Chang, Seok-Jong;Suh, Jang-Soo;Jeon, Byeong-Hwa;Nam, Ki-Yeul;Park, Hae-Kun
    • Journal of Ginseng Research
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    • v.18 no.2
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    • pp.95-101
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    • 1994
  • Saponin of Panax ginseng (C.A. Meyer) is composed of Protopanaxatriol (PT) and Protopanaxa- diol (PD). We investigated the effects of PT and PD on the contractility and $^{45}Ca$ uptake in the pig coronary artery. Isometric tension in the helical strips and $^{45}Ca$ uptake in the ring strips were measured in the presence or absence of PT and PD. PT and PD did not affect the high K+ (40 mM)-induced contraction but relaxed the ACh-induced contraction in a dose4ependent manner (1~10 mg/dl). The vasorelaxing effect of PT on the ACh-induced contraction was more potent than that of PD. Those relaxations were partially suppressed by the rubbing of endothelium removal. ACh-induced contraction in the $Ca^{2+}$-free Tyrode's solution was suppressed by the pretreatment of PT or PD. Following the depletion of ACh-sensitive intracellular $Ca^{2+}$ pool, ACh-induced contraction was suppressed by the pratreatment of PT or PD. With the pretreatment of PT or PD, $^{45}Ca$ uptake by high K+ (43 mM) was not changed but that by ACh was suppressed in the pig coronary artery. From the above results, we suggested that the vasorelaxing effect of PT and PD of Panax ginseng was due to inhibition of intracellular $Ca^{2+}$ release, inhibition of $Ca^{2+}$ uptake via receptor-operated $Ca^{2+}$ channels and in part a release of vasorelaxing factor from endothelium in pig coronary artery.

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A Study on the Recovery of EMG Power Spectrum and Pressure Pain Threshold of Masticatory Muscles after Sustained Isometric Contraction (저작근의 지속적인 등척성 수축후 근전도 power spectrum과 압력통각 역치의 회복에 관한 연구)

  • 이병철;김은숙;김영구
    • Journal of Oral Medicine and Pain
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    • v.23 no.4
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    • pp.433-445
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    • 1998
  • 본 연구는 정상인의 저작근에서 지속적인 등척성 수축후 근전도 power spectrum과 압력통각 역치의 회복 특성을 구명하기위해 시행되었다. 악안면 영역의 동통과 긴으장애의 벙력 및 현증이 ㅇ벗고 정상적인 교합관계를 가진 26명의 정상인(남자 14명, 여자 12명) 을 대상으로 최대근활성도의 70% 수준에서 인내가능 할 때까지의 등척성 수축과 수축후 회복기 동안의 근전도 power spectrum과 압력통각 역치를 컴퓨터를 이용한 근전도 시스텀과 전자식 압력통각계를 사용하여 분석한 결과 다음과 같은 결론을 얻었다. 1. 지속적인 등척성 수축 시작 시점의 중간주파수에서 남녀간에는 통계적으로 유의한 차이가 관철되지 않았지만, 근육간 비교에서는 전측두근에서 교근보다 유의하게 높게 나타났다(p<0.05). 2. 지속적인 등척성 수축전 암력통각 역치는 전축두근에서 교근보다 유의하게 높았고(p<0.001), 남성에서 여성보다 유의하게 높게 나타났다(p<0.05). 3. 지속적인 등척성 수축시 중간주파수와 압력통각 역치의 변화량은 성별간, 근육간에 우의한 차이가 관찰되지 않았다. 4. 지속적인 등척성 수축말기 중간주파수는 수축초기에 비하여 유의하게 감소하였으며(p<0.001), 이의 회복은 모든 근육에서 60초와 120초 사이에서 이루어 졌다. 5. 지속적인 등척성 수축후 압력통각역치는 수축전에 비해 유의하게 감소하였으며(p<0.001), 수축전 수준으로의 회복은 여자군의 전측두근과 교근에서는 30분후에 남자구느이 전측두근과 교근에서는 50분 후에 이루어졌다. 6. 지속적인 등척성 수축후 주관적인 동통이 소실된 시각은 여자군의 전축두근에서는 28분, 교근에서는 42분으로 남자군의 전측두근에서는 30분, 교근에서는 40분으로 나타났다.

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Effect of Inflatable Standing Surface With Different Levels of Air Pressure on Leg Muscle Activity (공기압 차이에 따른 불안정지지면이 다리 근활성도에 미치는 영향)

  • Park, Chi-Bok;Kim, Yong-Nam;Kim, Yong-Seong;Cho, Woon-Su;Jin, Hee-Kyung
    • Physical Therapy Korea
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    • v.20 no.2
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    • pp.1-10
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    • 2013
  • The purpose of this study was to determine the effect of the changes that occur in the leg muscle activity of unstable surface with different levels of air pressures. Three groups of college students have been placed randomly on unstable surfaces with different air pressures at group 1.0 psi ($n_1$=36), group 1.4 psi ($n_2$=40), and group 1.8 psi ($n_3$=40). Using surface electromyography, the recruitment of the tibialis anterior, peroneus longus, and the gastrocnemius was measured. Maximal voluntary isometric contraction was measured at the different air pressures based on the manual muscle test, then normalizing the value to %maximal voluntary isometric contraction (%MVIC). The tibialis anterior muscle activity was significant change from the unstable surface with difference levels of air pressures between group 1.0 psi and 1.8 psi and between group 1.4 psi and 1.8 psi. peroneus longus muscle activity was significant changes in muscle activity occurred between 1.0 psi and 1.4 psi group and between 1.0 psi and 1.8 psi group. Gastrocnemius muscle activity was significant change in muscle activity occurred between 1.0 psi and 1.4 psi group and between 1.0 psi and 1.8 psi group. In conclusion it identify that 1.0 psi group is most effective on muscle activity than the other groups. These suggest that the rehabilitation or strengthening of patients with ankle injuries, balance exercise with low air pressure like 1.0 psi can be more effective.

Effect of Diamond Taping Applied to the Elbow Joint on Wrist Extensor Muscle Activity in Healthy Subjects (팔꿉관절 부위에 적용한 다이아몬드 테이핑이 정상인의 파악력 수준별 손목 폄근의 근활성도에 미치는 영향)

  • Huang, Tian-zong;Kim, Suhn-yeop
    • Physical Therapy Korea
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    • v.27 no.2
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    • pp.118-125
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    • 2020
  • Background: Lateral epicondylitis (LE) is the most common chronic musculoskeletal pain condition of the upper extremities. LE is often related to forceful grip activities that require isometric contraction of the wrist extensors. A previous study evaluated the effect of the diamond taping technique on grip strength and pain; however, there has been no report on the change in the electromyography (EMG) findings of wrist extensors. Objects: The aim of this study was to investigate the effect of diamond taping technique, using a rigid tape, on the EMG activities of the extensor carpi radialis (ECR) during grip activities. Methods: Twenty-four healthy subjects (mean age = 21.50 ± 2.76 years) volunteered to participate in this study. The subjects were instructed to perform forceful grip activities with and without diamond-type taping on the origin area of the ECR. Grip strength tests were performed at 100%, 75%, 50%, and 25% for maximal isometric contraction force. EMG data were collected from the ECR. Repeated measure analysis of variance was used to analyze the effect of grip force and taping (with and without). Statistical significance levels were set at α = 0.05. Comparison of the results with and without taping at different grip force were analyzed using independent t-test. Statistical significance levels were set at α = 0.01. Results: Statistically significant association was observed between the taping application and forceful grip activity as revealed by the EMG data of the ECR (p < 0.05). EMG of the ECR significantly reduced for all muscle strength levels (p < 0.01) after taping. Conclusion: This study shows an impressive effect of the diamond taping technique, using rigid tape, on wrist extensors during grip activities. Decreasing muscle activity via this taping approach could be utilized to enhance pain-free grip force and reduce pain in patients with LE. Our study suggested that this taping technique could be considered as an effective management strategy of LE.

Effect of Paraspinal Muscle Fatigue on Proprioception and Coordination of the Lower Limb (부척추근의 근피로가 하지의 고유수용성 감각과 협응 능력에 미치는 영향)

  • Park, Min-Chull;Kim, Hyoung-Su;Lee, Sang-Youl;Lee, Myoung-Hee;Goo, Bong-Oh;Yoon, Chang-G
    • Journal of the Korean Society of Physical Medicine
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    • v.3 no.4
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    • pp.255-260
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    • 2008
  • Purpose : This study was performed to find out the influence of the change on proprioception and coordination of the lower limb by experimentally induced paraspinal muscle fatigue, Methods : Twelve subjects(6 males, 6 females) with no history low back and lower limbs problem volunteered for this study. Subjects were pre-tested proprioception and coordination using the MR-FSS(Mornitored Rehab Functional Squat System). And then the subjects performed isometric paraspinal muscles contraction for induced muscle fatigue. Muscle fatigue was defined surface EMG(MP 150). After isometric contraction, the subjects were post-tested using the MR-FSS. Results : In comparison of coordination, deviation of concentric coordination was increased(from $0.50{\pm}0.13cm$ to $0.67{\pm}0.21$)(p<0.05) and deviation of eccentric coordination was also increased(from $0.51{\pm}0.15cm$ to $0.70{\pm}0.26cm$)(p<0.05). And deviation movement of proprioceptive test was increased(from $4.98{\pm}1.80cm$ to $5.69{\pm}1.98cm$), but there was no significant different(p>0.05). Conclusion : Fatigue of paraspinal muscles was decreased concentric and eccentric coordination of the lower limb.

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The Effect Spiral Way Movement of a Trunk Exerts on the Movement Ability (체간의 나선방향운동이 운동능력에 미치는 효과)

  • Lee, In-Hak;Nam, Taek-Gil
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.5 no.2
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    • pp.35-45
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    • 2007
  • The purpose of this study was to examine spiral way movement of a trunk exerts on the movement ability. The details established to achieve for this article. This examination confirmed the weight, weight/height2 index, ratio of lumbar to pelvic, musculoskeletal quantity, push up for 2 minute, pitch a ball and voluntary isometric contraction with flexion and extension of knee joint of the subjects with spiral direct movement. Healthy eighteen subjects who understand fully the significance of procedure, consented to a plan, without neuromuscular disease were participated in two groups of experiment. The group were a spiral movement(9), rectilinear movement(9). Trunk movement tested 2 sessions of a spiral movement and rectilinear movement with a push up for 2 minute, 5days per a week, for the 4 weeks. This experiment tested 3 times with a sufficient rest for fatigue limitation. An analysis of the results used a paired samples t-test for difference from before and after experiment. The following results were obtained; At an internal change of the body, the musculoskeletal quantity was increased significantly to spiral movement group, but the weight was increased significantly, the musculoskeletal quantity was not significant to rectilinear movement. The movement ability evaluation for a external change was increased significantly in a push up for 2 minute, pitch a ball, isometric contraction with extension of knee joint of a spiral movement group, but a push up for 2 minute was increased significantly in a push up for 2 minute on the abdominal muscle training of a rectilinear movement group. As compared with a rectilinear movement, a spiral movement was more effect by cooperation with nerve and musculoskeletal system and an increase in movement ability was caused by learning acknowledgment, muscular reeducation. These results lead us to the conclusion that a spiral movement of trunk was more effect than a rectilinear movement, the coordination of nerve and musculoskeletal system was of importance of Multi-direction movement. Therefore, A further studies concerning the therapeutic exercise intervention and active-dynamic analysis could enhance the development of the most effect on the trunk.

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Comparison of Maintenance Period on Muscle Activity and MVIC according to Type of Stretching (스트레칭의 유형에 따른 근활성도 및 최대 수의적 등척성 수축력의 유지기간 비교)

  • Jeong, Jin-Gyu;Lee, Byung-Hoon;Yoo, Jae-Young;Kim, Yong-Nam
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.8
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    • pp.1271-1276
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    • 2013
  • This study selected 22 male subjects to examine the maintenance period of static and ballistic stretching applied to rectus femoris, divided them into 11 static stretching group and 11 ballistic stretching group and analyzed changes in median frequency and in maximal voluntary isometric contraction before stretching and at 30 sec, 1 min, 3 min, 5 min, and 10 min after stretching. Median frequency showed significant differences in changes according to time and groups after the test of main effects. It was reduced after 3 min. in both static stretching and ballistic stretching groups and then increased again. Maximal voluntary isometric contraction showed significant differences in changes according to time and groups from the results of the main effect test. Static stretching group was reduced at 3 min after the experiment and then increased after that and ballistic stretching group was reduced at 5 min after the experiment and then increased again. In conclusion, changes were shown according to time after stretching and the effects of ballistic stretching were maintained a little longer than those of static stretching.

Comparison of the immediate effect of hamstring stretching techniques on hamstring muscle range of motion, pressure pain threshold and muscle tone

  • Yu, June-Su;Shin, Won-Seob
    • Physical Therapy Rehabilitation Science
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    • v.8 no.4
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    • pp.210-217
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    • 2019
  • Objective: This study was conducted to compare the immediate effect of hamstring stretching techniques of static stretching, proprioceptive neuromuscular facilitation (PNF) hold-relax and PNF irradiation on the hamstring muscle. Design: Three-group pretest-posttest design. Methods: Fifty-one subjects with shortened hamstrings were randomly assigned to the static stretching group (n=17), PNF hold-relax group (n=17), and the PNF irradiation group (n=17). All subjects performed an active knee extension (AKE) test to assess for the lower extremity with a shortened hamstring. The static stretching group performed stretches by lifting their leg to the maximum extent (3 times, 30 seconds). The PNF hold-relax group performed maximal isometric contraction against the experimenter's resistance (3 times, 10 seconds). The PNF irradiation group performed maximum isometric contraction against the experimenter's resistance toward the direction of the body (5 times, 5 seconds). The pre and post-tests measured range of motion (ROM), pressure pain thresholds (PPT) and muscle tone. Results: There were significant differences in ROM and PPT between pre and post intervention in each group (p<0.05). There was a significant difference only in the ROM among groups (p<0.05). Post-hoc analysis showed that the changes in ROM occurred in the order of the PNF hold-relax group, static stretching group and PNF irradiation group (p<0.05). Conclusions: The findings of this study suggest that the PNF irradiation technique may improve ROM and may be used to improve ROM similar to other stretching techniques. Therefore, the PNF irradiation technique could be included in stretching programs and can be used as a suitable stretching method depending on the situation.

Development and evaluation of estimation model of ankle joint moment from optimization of muscle parameters (근육 파라미터 최적화를 통한 발목관절 모멘트 추정 모델 개발 및 평가)

  • Son, J.;Hwang, S.;Lee, J.;Kim, Y.H.
    • Journal of Biomedical Engineering Research
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    • v.31 no.4
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    • pp.310-315
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    • 2010
  • Estimation of muscle forces is important in biomechanics, therefore many researchers have tried to build a muscle model. Recently, optimization techniques for adjusting muscle parameters, i.e. EMG-driven model, have been used to estimate muscle forces and predict joint moments. In this study, an EMG-driven model based on the previous studies has been developed and isometric and isokinetic contraction movements were evaluated to validate the developed model. One healthy male participated in this study. The dynamometer tasks were performed for maximum voluntary isometric contractions (MVIC) for ankle dorsi/plantarflexors, isokinetic contraction at both $30^{\circ}/s$ and $60^{\circ}/s$. EMGs were recorded from the tibialis anterior, gastrocnemius medialis, gastrocnemius lateralis and soleus muscles at the sampling rate of 1000 Hz. The MVIC trial was used to customize the EMG-driven model to the specific subject. Once the subject's own model was developed, the model was used to predict the ankle joint moment for the other two dynamic movements. When no optimization was applied to characterize the muscle parameters, weak correlations were observed between the model prediction and the measured joint moment with large RMS error over 100% (r = 0.468 (123%) and r = 0.060 (159%) in $30^{\circ}/s$ and $60^{\circ}/s$ dynamic movements, respectively). However, once optimization was applied to adjust the muscle parameters, the predicted joint moment was highly similar to the measured joint moment with relatively small RMS error below 40% (r = 0.955 (21%) and r = 0.819 (36%) and in $30^{\circ}/s$ and $60^{\circ}/s$ dynamic movements, respectively). We expect that our EMG-driven model will be employed in our future efforts to estimate muscle forces of the elderly.

Comparison of the Muscle Activities in the Lower Extremities during Weight-bearing Exercises

  • Kim, Eun Ja;Hwang, Byong Yong;Kim, Mi Sun;Kim, Ik Hwan
    • The Journal of Korean Physical Therapy
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    • v.24 no.3
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    • pp.216-222
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    • 2012
  • Purpose: Weight-bearing exercise is a type of physical exercise that is widely performed for rehabilitation after acquiring nervous-system diseases or sports-related injuries. It is one of the most commonly prescribed rehabilitation programs for strengthing of the lower extremities. Weight-bearing exercise is important for the conduct of such activity of daily living (ADLs) as walking, and up and down the stairs. The purpose of this study was to investigate the muscle activities during one-leg standing and one-leg squatting, the two most representative weight-bearing exercises. Methods: A total of 43 elderly (60~70 years old) males who could perform weight-bearing exercises were included in the study. During the one-leg standing and one-leg squatting, the electromyographic (EMG) signals were quantified as maximum voluntary isometric contraction (%MVIC) using surface EMG, and then the muscle activities of the lower extremities during the two exercises were compared. For statistical analysis, an independent sample t-test and one-way ANOVA were performed. Results: The results of the study are as follows: (1) in the one-leg standing, the activity of the gluteus medius was the greatest among the vastus medialis, vastus lateralis, bicep femoris, (2) in the one-leg squatting, the activity of the vastus medialis was the greatest; and (3) the activity was greater in the one-leg squatting than in the single-leg standing exercise. Conclusion: The one-leg standing and squatting exercises are suitable for strengthening the muscles for the prevention of and recovery from lower-extremity injury, and for functional ADL in elderly people. In addition, dynamic exercise was shown to be more effective than static exercise for strengthening the muscles.