• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.181-188
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• 2022

Objective: The purpose of this study to investigate the correlations among the motor function, balance, and gait velocity and the strength that could explain the variation of gait velocity of chronic stroke survivors. Design: This was a cross-sectional cohort study. Methods: Thirty hemiplegic stroke survivors hospitalized in an inpatient rehabilitation center were participated. The muscle tone of ankle plantarflexor and muscle strength of ankle dorsiflexor were measured respectively with modified Ashworth scale (MAS) and hand-held dynamometer. And the motor recovery and function with Fugl-Meyer assessment (FMA), balance with Berg balance scale (BBS) and timed up and go (TUG) test were measured. Gait velocity was measured with GAITRite. The correlation among motor function, muscle tone, muscle strength, balance, and gait were analyzed. In addition, the strength of the relationship between the response (gait velocity) and the explanatory variables was analyzed. Results: The gait velocity had positive correlations with FMA, muscle strength, and BBS, and negative correlation with MAS and TUG. Regression analysis showed that TUG (𝛽=-0.829) was a major explanatory variable for gait velocity. Conclusions: Our results suggest that gait velocity had correlations with muscle strength, MAS, FMA, BBS, and TUG. The tests and measurements affecting the variation of gait velocity the greatest were TUG, followed by FMA, BBS, muscle strength, and MAS. This study shows that TUG would be a possible assessment tool to determine the variation of gait velocity in stroke rehabilitation.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.93-102
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• 2001

The relaxation response is a state of profound rest, creates physiological responses directly opposite to the stress response. The relaxation response can be used to counteract the harmful effects of stress. The relaxation response can be elicited by a number of techniques such as diaphragmatic breathing, meditation, progressive muscle relaxation, autogenic training, biofeedback, etc. These relaxation methods in any mental or physical conditions associated with distress and even in normal people have useful benefits for stress control and health enhancement. These relaxation techniques are but one part of a comprehensive stress management program, through regular and continuous practice appropriate for each person, they will make an effective role in stress management. In this review, author reviewed how to practically use meditation, progressive muscle relaxation and autogenic training, in more detail. In the treatment of various stress-related disease, especially in psychiatric disorders, the relaxation technique may be a useful complement to conventional treatment and serves as an intervention between stress and disease.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.233-241
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• 1995

The nonapeptide bradykinin has been shown to exhibit an array of biological activities including relaxation/contraction of various smooth muscles. In order to investigate the effects of bradykinin on the contractility and the electrical activity of antral circular muscle of guinea-pig stomach, the isometric contraction and membrane potential were recorded. Also, using standard patch clamp technique, the $Ca^{2+}-activated$ K currents were recorded to observe the change in cytosolic $Ca^{2+}$ concentration. $0.4 {\mu}M$ bradykinin induced a triphasic contractile response (transient contraction-transient relaxation-sustained contraction) and this response was unaffected by pretreatment with neural blockers (tetrodotoxin, atropine and guanethidine) or with apamin. Bradykinin induced hyperpolarization of resting membrane potential and enhanced the amplitude of slow waves and spike potentials. The enhancement of spike potentials was blocked by neural blockers. Both the bradykinin-induced contractions and changes in membrane potential were reversed by the selective $B_2$-receptor antagonist $(N{\alpha}-adamantaneacetyl-_{D}-Arg-[Hyp, Thy,_{D}-Phe]-bradykinin)$. In whole-cell patch clamp experiment, we held the membrane potential at -20 mV and spontaneous and transient changes of Ca-activated K currents were recorded. Bradykinin induced a large transient outward current, consistent with a calcium-releasing action of bradykinin front the intracellular calcium pool, because such change was blocked by pretreatment with caffeine. Bradykinin-induced contraction was also blocked by pretreatment with caffeine. From these results, it is suggested that bradykinin induces a calciumrelease and contraction through the $B_{2}$ receptor of guinea-pig gastric smooth muscle. Enhancement of slow wave activity is an indirect action of bradykinin through enteric nerve cells embedded in muscle strip.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.778-786
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• 2018

We investigated the effect of different exercise intensities on biomarkers of oxidant-antioxidant balance, inflammation, and muscle damage. Eighteen healthy and untrained male subjects were enrolled.Subjects were randomly and equally assigned to a moderate-intensityexercise(MIE, $65%VO_2max$) group(n=9) or a high-intensity exercise(HIE, $85%VO_2max$) group(n=9).Blood samples were collectedimmediately pre-exercise, post-exercise, and 60min post-exercisetoexamine oxidant-antioxidant balance(d-ROMs; BAP), inflammation(CRP; fibrinogen), muscle damage(CK; LDH), and lactate. Serum d-ROMs and BAP levels were significantly increased post-exercise compared with pre-exercise levels in HIE group(p<0.05). Lactate levels were significantly increased post-exercise compared pre-exercise levels in both the MIE and HIE groups(p<0.05). In addition, post-exercise serum d-ROMs and plasma lactate levels were significantly higher in the HIE group than in the MIE group(p<0.05). These results suggest that although relatively high-intensity exercises may increase oxidative stress levels in the body, they do not produce inflammatory response and/or muscle damage.

• YAKHAK HOEJI
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• v.32 no.6
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• pp.402-414
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• 1988

In order to clarify the receptor types and mechanisms underlying the positive inotropic effect of dopamine on the mammalian ventricular myocardium, the action potential, its first derivatives and isometric contraction of the rabbit papillary muscle were recorded using a force transducer and glass capillary microelectrodes filled with 3M KCl. The results were as follows; (1) In normal Tyrode solution, the contractile force was increased and duration of action potential was shortened with increments of dopamine concentration ($10^{-6}-10^{-4}M$). (2) The dose-response curve was markedly shifted to the right by pretreatment with reserpine (5mg/kg i.p., 24hrs prior to the experiment). (3) In 19mM $K^+-Tyrode$ solution, the duration of action potential, maximum rate of rise (V_{max}) of action potential and overshoot were significantly increased with increments of dopamine concentration ($10^{-6}-10^{-4}M$). (4) The inotropic effect of dopamine on the rabbit papillary muscle pretreated with reserpine was antagonized by atenolol ($10^{-6}M$), but not by phentolamine ($3{\times}10^{-6}M$). (5) In rabbit papillary muscle partially depolarized by 19mM $K^+-Tyrode$ solution, slow electrical response (calcium mediated action potential) as well as contraction were restored by dopamine ($10^{-4}M$); this restoration was blocked by calcium antagonists ($3{\times}10^{-5}M$ $LaCl_3{\cdot}6H_2O$, $3{\times}10^{-6}M$ diltiazem) or ${\beta}-adrenoceptor$ antagonist ($3{\times}10^{-6}M$ atenolol), but not affected by ${\alpha}-adrenoceptor$ antagonist ($10^{-5}M$ phentolamine, $3{\times}10^{-6}M$ yohimbine) or vascular dopaminergic receptor antagonist ($10^{-5}M$ haloperidol). The above results may be interpreted as that the positive inotropic effect of dopamine through both direct and indirect action are caused by increase in slow inward current ($Ca^{2+}$ influx into themyocardial cell), and the direct action is mainly due to the stimulation of ${\beta}-adrenoceptors$ in the rabbit papillary muscle.

• Korean Journal of Acupuncture
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• v.17 no.1
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• pp.67-73
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• 2000

The purpose of the present study is to determine the effect of Radix Stemonae on histamine induced tracheal smooth muscle contraction in guinea pigs. Guinea pig(500g, male) were killed by $CO_2$ exposure and a segment (8-10mm) of the thoracic trachea from guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine (His) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine ($10^{-7}∼10^{-4}M$). Contractions evoked by His ($ED_{50}$) were inhibited significantly by Radix Stemonae. In guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 87.4% (p<0.01) after $100{\mu}l/ml$ Radix Stemonae. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Radix Stemonae fell to 16.2% in guinea pig induced by histamine contraction. Indomethacin and methylene blue($10^{-7}M$) did not significantly alter the inhibitory effect of Radix Stemonae. These results indicate that Radix Stemonae can relax histamine induced contraction of guinea pig tracheal smooth muscle, and that this inhibition involves sympathetic effects.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1183-1194
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• 2006

The aim of this study was to identify the characteristics of the flexion withdrawal reflex modulated by the hip angle and hip movement in spinal cord injury (SCI). The influence of the hip position and passive movement were tested in 6 subjects with chronic SCI. Each subject placed in a supine position and lower leg was fixed with the knee at 5 -45 degree flexion and the ankle at 25-40 degree plantar flexion. A train of 10 stimulus pulses were applied at 200 Hz to the skin of the medial arch to trigger flexion reflexes. From results of the regression analysis, static properties of normalized muscle activation of flexor muscles have the linear relationship with respect to hip angle (P< 0.05). In order to verify the neural contribution of flexion reflex, we compared the static and dynamic gains of estimated muscle activations with measured EMG of ankle flexor muscle. Form this study, we postulate that the torque and muscle response of flexion withdrawal reflex have linear relationship with hip angle and angular velocity.

• Journal of the Korea Society of Computer and Information
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• v.24 no.9
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• pp.97-102
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• 2019

Several studies have recently demonstrated that skeletal muscle is an endocrine organ releasing and expressing myokines acting in an endocrine or paracrine manner. Irisin is a hormene-like myokine induced after physical exercise by muscle fibers. It was primarily recognized as a molecule able to advance the "browning response" in white adipose tissue, however, it has been recetly identified that irisin also has a fundamental role in the control of bone mass. We study evidence for its possible skeletal effects, including the fundamental role that irisin is involved in the control of bone mass, with beneficial effects on geometry and cortical mineral density. As loss of muscle mass and bone density occurs with immobility, metabolic disease and aging, future studies researching the efficacy of irisin in reversing muscle wasting and restoring bone would be important to proving irisin as a molecule that combines helpful effects for treating muscular atrophy and osteoporosis in elderly people.

• Herbal Formula Science
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• v.25 no.4
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• pp.499-508
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• 2017

Objectives : Skeletal muscle atrophy occurs in response to a variety of conditions. The unloading to muscle occurs clinically in limb immobilization, bed rest, spinal cord injury and peripheral nerve damage, resulting in significant loss of muscle mass and force production. Muscle disuse is accompanied by an increase in apoptotic signaling, which mediates some of the responses to unloading in the muscle. In this study we tested the hypothesis that Daeyeoung-jeon extract would improve muscle recovery after reloading following disuse. Method : Twenty young male Sprague-Dawley rats were used for the studies. The hindlimb immobilization was performed with casting tape to keep the left ankle joint in a fully extended position. No intervention was performed on the right leg and used as intact region. The Rats in Daeyeoung-jeon treated group (DYJ) were orally administrated Daeyeoung-jeon water extract, and rats of Control group were given with saline only. After 2 weeks of immobilization, all animals were sacrificed, and the whole gastrocnemius muscles were dissected from both legs. The morphology of right and left gastrocnemius muscles in both DYJ and Control groups were assessed by hematoxylin and eosin staining. Moreover, to investigate the immobilization-induced muscular apoptosis, the immunohistochemical analysis of Bax and Bcl-2 was carried out. Results : Daeyeoung-jeon represented the significant protective effects against the reductions of the left gastrocnemius muscles weight and average cross section area to compared with Control group. The treatment with Daeyeoung-jeon extract significantly reduced the immunoreactivity of BAX and increased the immunoreactivity of Bcl-2 in gastrocnemius muscle compared with Control group. Conclusion : Daeyeoung-jeon has protective effects against immobilization-induced muscle atrophy by regulating the activities of apoptosis-associated BAX/Bcl-2 proteins in gastrocnemius muscle.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.528-533
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• 1997

Twenty four female Sprague-Dawley rats weighing about 190 g were used to examine changes in muscle cAMP concentrations and steady-state levels of skeletal muscle ${\alpha}$-actin mRNA during chronic administration of cimaterol, a ${\beta}$-adrenergic agonist. Cimaterol was mixed in a powdered rat diet at 10 mg/kg diet. At 3 and 21 days after the start of treatment, skeletal muscle and heart samples were collected for the measurement of cAMP concentrations and skeletal muscle ${\alpha}$-actin mRNA levels. Cimaterol increased (p < 0.01) body weight gain gradually during the first seven days of the trial period, but not thereafter. Most skeletal muscle weights and the ratio of muscle weight to body weight were increased (p < 0.05) by cimaterol treatment both at 3 and 21 days. Heart weight was also increased (p < 0.05) by cimaterol treatment at 3 and 21 days, but the ratio of heart weight to body weight was increased (p < 0.05) only at 3 day. Cimaterol decreased (p < 0.05) cAMP concentration of gastrocnemius muscle at both 3 and 21 days after treatment. However, cimaterol tended (p = 0.07) to increase cAMP concentration at 3 days in the heart. Cimaterol tended (p = 0.08) to increase the steady-state level of ${\alpha}$-actin mRNA by 60% in gastrocnemius muscle at 3 days but had no effect at 21 days. The results indicate that the pattern of hypertrophic response to chronic dietary administration of cimaterol is different between cardiac and skeletal muscle. In skeletal muscles it appears that the hypertrophy induced by cimaterol is partly due to stimulated myofibrillar protein synthesis at a pre-translational level.