• The Journal of Korean Physical Therapy
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• 제2권1호
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• pp.47-63
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• 1990

The purpose of this study was to determined the effect of low-frequency electrical stimulation on the denervated gastrocnemius muscles of the albino rats, Sprague-Dawley. Fifteen Sprague-Dawley adult male albino rats were divided into non-treated (normal) group, denervated (control) group, denervated and electrical stimulated (experiments). The gastrocnemius muscles of the right leg were submaximally stimulated with 30 Hz electrical stimulation. After 4-week period, the animals were sacrificed, and muscle were removed, fixed by immersion, and processed for light and electron microscopy. The numbers of Ag-NOR increased significantly (p<0.001), but significant reductions of girth(p<0.01), wet muscle weight (p<0.001), high glycogen content fiber (p<0.01), and mitochondrial number (p<0.05) were found in denervated control group. In comparison with control group, significant increase of right leg girth (p<0.05), wet muscle weight (p<0.001), high glycogen content fiber (p<0.05), numbers of Ag-NOR(p<0.001), number of mitochondria (p<0.01), mitochondrial volume found in electrical stimulated experimental group. The results suggest that the electrical stimulation of the muscle partially prevented the denervated atrophy in the rat gastrocnemius muscles.

• PNF and Movement
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• 제13권2호
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• pp.95-102
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• 2015

Purpose: The purpose of this study was to analyze the effect of arm flexion patterns of proprioceptive neuromuscular facilitation on muscle activation in the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used. Methods: This study used an electromyogram (MP150, Biopac Systems, USA) to measure muscle activation in 20 healthy male students. Comparative analysis was completed on muscle activation of the vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius of the contralateral lower extremity. Open kinematic chain and closed kinematic chain positions were used with a unilateral arm flexion-abduction-external rotation pattern. Paired t-tests using the SPSS 12.0 for Windows analyzed the data produced by the electromyogram. Results: There was a statistically significant difference in muscle activation in the biceps femoris, gastrocnemius, and tibialis anterior when the open kinematic chain and closed kinematic chain positions were compared (p < 0.05). Conclusion: The biceps femoris, gastrocnemius, and tibialis anterior muscles showed greater muscle activation in the closed kinematic chain position when compared to the open kinematic chain position.

• PNF and Movement
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• 제12권3호
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• pp.173-179
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• 2014

Purpose: The purpose of this study is to analyze the effect of arm leg flexion patterns of proprioceptive neuromuscular facilitation on the muscle activation of the contralateral lower extremity. Methods: In this study, Electromyogram MP150(Biopac system, USA) was applied to 20 healthy male subjects. Unilateral arm flexion- abduction- external rotation pattern and Unilateral leg flexion- adduction- external rotation with knee flexion pattern were applied within mid range of the supine position for measurement. The muscle activation of vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius(medialis) muscle of the contralateral lower extremity were compared and analyzed during the applications. Results: The results of this study were summarized as follows: There was a statistically significant difference in the muscle activation of vastus lateralis and biceps femoris between the arm and leg patterns(P<0.05). There was a statistically significant difference in the muscle activation of gastrocnemius and tibialis anterior between the arm and leg patterns(P<0.05). Conclusion: contralateral vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior muscles show the higher muscle activation in the leg pattern than one in the arm pattern.

• The Journal of Korean Physical Therapy
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• 제33권3호
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• pp.162-167
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• 2021

Purpose: A hyperextended knee is described as knee pain associated with an impaired knee extensor mechanism. Additionally, a hyperextended knee may involve reduced position sense of the knee joint that decreases the individual's ability to control end-range knee extension movement. The purpose of this study was to investigate the effects of visual biofeedback information for plantar pressure distribution on knee joint angle and lower extremity muscle activities in participants with hyperextended knees. Methods: Twenty-three participants with hyperextended knees were recruited for the study. Surface electromyography signals were recorded for the biceps femoris, rectus femoris, gastrocnemius, and tibialis anterior muscle activities. The plantar pressure distribution was displayed and measured using a pressure distribution measuring plate. Knee joint angle kinematic parameters were recorded using a motion analysis system. The visual biofeedback condition was the point at which the difference between the forefoot and backfoot plantar foot pressure on the monitor was minimized. The Wilcoxon signed-rank test was used to determine the significance between the visual biofeedback condition and the preferred condition. Results: The knee joint angle was significantly decreased in the visual biofeedback condition compared to that in the preferred condition (p<0.05). The rectus femoris and gastrocnemius muscle activities were significantly different between the visual biofeedback and preferred conditions (p<0.05). Conclusion: The results of this study showed that visual biofeedback of information about plantar pressure distribution is effective for correcting hyperextended knees.

• The Journal of Korean Physical Therapy
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• 제34권4호
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• pp.187-191
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• 2022

Purpose: The purpose of our study aimed to identify the effect of static and dynamic bridge exercise with gym ball using gym ball on muscle activation of trunk and lower-limb in healthy individuals. Methods: A total of 20 healthy adults participated in this study. The individuals performed general bridge exercise, static and dynamic bridge exercise using gym ball. During the three methods of bridge exercises, electromyography (EMG) data (% maximum voluntary isometric contraction) of the rectus abdominis, erector spinae, biceps femoris, and gastrocnemius were recorded using a wireless surface EMG system. Results: Rectus abdominis activation showed significantly greater during dynamic bridge exercise compared with general bridge exercise and dynamic bridge exercise. Erector spinae, biceps femoris, and gastrocnemius were greater during static and dynamic bridge exercise compared with general bridge exercise. Conclusion: Based on our results, bridge exercise using gym ball, particularly integrating lower-limb movement, could be a useful method to enhance muscle activation of trunk and lower-limb (rectus abdominis, erector spinae, biceps femoris, and gastrocnemius).

• 한국산학기술학회논문지
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• 제13권6호
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• pp.2632-2640
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• 2012

본 연구의 목적은 지연성근통증에 대한 내측 비복근 초음파 영상의 측정도구로서의 가능성에 대해 알아보고자 함에 있다. 본 연구는 2011년 4월 21일부터 4월30일까지 실시되었다. 평소 규칙적인 운동을 하지 않으며, 최근 외상의 경험, 근골격계 질환, 심혈관계 질환이 없고 약물을 복용하지 않는 35명의 건강한 성인이 참여하였다. 대상자들은 5시간의 등반을 통해 지연성근통증을 유발하였으며, 지연성근통증 전과 지연성근통증 후 24, 48, 72시에 통증(visual analogue scale :VAS), 혈중 크레아틴 키나아제(creatine kinase: CK) 활성도, 족저 굴곡근의 최대근수축력(maximal voluntary isometric contraction: MVlC)을 측정하였고, 이 측정값과 초음파로 측정한 내측 비복근의 우상각을 비교하였다. 연구의 결과는 다음과 같다. 통증지표, 혈중 크레아틴 키나아제 활성도, 족저 굴곡근 최대등척성근수축력에 측정시기에 따른 유의한 차이가 발생하였으며(p<0.05), 내측 비복근 우상각에서도 측정시기에 따른 유의한 차이가 발생하였다(p<0.05). 또한 변수 간 측정시기에 따른 변화의 흐름이 일치하는 것을 확인하였다. 본 연구를 통해 초음파 검사를 통한 내측 비복근 우상각의 시간경과에 따른 변화 측정이 지연성근통증을 감지하는 새로운 측정방법으로 사용될 수 있을 것이라 생각한다.

• Nutritional Sciences
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• 제8권3호
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• pp.181-188
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• 2005

We investigated the effects of diet manipulation on pro- and macro-glycogen accumulation and mobilization during exercise in different kinds of muscle fiber and tissue. Thirty-two Sprague-Dawley rats were divided into groups representing one of two dietary conditions: high fat (HF, n=16) or standard chow (CHOW, n=16). Each dietary group was fm1her divided into control (REST, n=8) and exercise (EXE, n=8). After an eight-week dietary intervention period, the animals in EXE swam for 3 hours while the animals in REST remained at rest Skeletal muscle (soleus, red gastrocnemius and white gastrocnemius) and liver samples were then dissected out and used for analyses. 1here was no statistical difference in body weight between the animals in the HF and mow groups (p>.05). Three hours of exercise significantly increased plasma free fatty acid (FFA) concentration in the animals in the CHOW group but not in the animals in the HF group. Both citrate. synthase (CS) and $\beta$-hydroxyacyl dehydrogenase ($\beta$-HAD) activities in skeletal muscles were higher in the HF group than in the mow group. CS and $\beta$-HAD activities were also the highest in red gastrocnemius and the lowest in white gastrocnemius. At both time points (i.e., rest and immediately after exercise) intramuscular triglyceride (IMTG) and liver TG concentrations were significantly higher in the HF compared to the CHOW. IMTG and liver TG changed selectively in the CHOW. Except in white gastrocnemius muscle, there was no significant difference in total glycogen content between HF and mow at rest. Although exercise significantly lowered total glycogen content in all groups and tissues (p<.05), the degree of reduction was markedly greater in the mow than in the HF. Whereas changes in proglycogen concentration showed a trend similar to those of total glycogen, alterations in macroglycogen concentrations clearly differed from those of total glycogen. Specifically, the degree of reduction of macroglycogen following three hours of exercise was substantially greater in the CHOW than in the HF. These results suggest that metabolic alterations induced by a long-term high fat diet may be caused by macro-glycogen rather than pro-glycogen.

• Nutritional Sciences
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• 제1권1호
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• pp.3-7
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• 1998

The aim of the present investigation was to see whether an anabolic steroid, nandrolone phenylpropionate (NPP), exerts protienanabolic effects under such adverse nutritional conditions as protein deficiency and protein-energy malnutrition in male rats. feeding on a low-protein (8% casein) diet resulted in a marked reduction in body weight gain that was associated with reductions in body protein and protein content of gastrocnemius muscle. Administration of NPP (4 mg/kg body weight) did not alter muscle and body protein depletion induced by a low-protein diet. 50% food restriction caused reductions in body protein and in protein content of gastrocnemius muscle. These reductions were partially prevented by NPP (4 mg/kg body weight). Food restriction did not affect plasma concentration of corticosterone, insulin, or tetosterone plus dihydrotestosterone. On the other hand, neither plasma concentration of corticosterone nor insulin were affected by NPP. The present results show that anabolic steroids do not express anabolic effects under conditions of protein deficiency, but in protein-energy malnutrition, anabolic steroids exert their anabolic effects even in male rats.

• Journal of Nutrition and Health
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• 제29권8호
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• pp.867-873
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• 1996

This study was undertaken to determine whether the anabolic steroid nandrolone phenylpropionate(NPP) can inhibit the muscle atrophy and reduction in muscle protein synthesis caused by glucocorticoids in female rates. Daily injections of 50mg/kg of corticosterone for eight days induced significant reductions in body weight gain and protein without affecting food intake. The mass, protein and RNA content, ratio of RNA to protein, and fractional rate of protein synthesis, measured in vivo, of gastrocnemius muscle were all significantly reduced by corticosterone treatement. Simultaneous administration of NPP at a dose of 10mg/kg with corticosteorne (50mg/kg) fully inhibited the reductions in the mass, protein and RNA content of gastrocnemius muscle, and body weight gain and protein with no alteration in food intake but the reduction in fractional rate of muscle protein syntheis was only partially prevented. The results indicate that the anabolic steroid nandrolone phenylpropionate is capable of preventing muscle atrophy in female rats treated with excess corticosterion.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.61-70
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• 1994

A new method is used to record the actual shortening produced during the auxotonic activity of the sartorius (SAR), gastrocnemius (CAS) and rectus abdominis (RAB) muscles of a lizard Uromastix. The auxotonic twitch and tetanus records thus obtained were used for the first time to calculate the coefficient of linear shortening (COLS). This coefficient represent the relative Index between change in length $(\Delta\;L=L_0-L_1)$ and tension $({\Delta}P\;P_0-P_1)$ due to shortening at the steepest rising phase of the twitch and tetanus, recorded at resting length. In addition to this, maximum shortening $(S_{max})$ and auxotonic tensions were also determined at resting lengths of these muscles. The COLS was found to express the speed of shortening and auxotonic tensions are suggested to be of value to express the internal architecture of SAR, GAS & RAB muscles. The results are discussed in terms of contractile and elastic elements of the muscles alongwith the importance of shortening at resting lengths in skeletal muscles.