• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.1 no.2
• /
• pp.21-30
• /
• 2003

The purpose of this study was to know the effect of aquatic-exercise on muscle atrophy which induced by steroid injection. The forty-eight Sparague-Dawley adult male rats were assigned to the 4 groups; GroupI(distilled water injection), GroupII(steroid injection), GroupIII(distilled water injection and aquatic exercise), GroupIV(steroid injection and aquatic exercise). We observed their body weight, histological change by PAS stein. The results of this study were as follows; 1. After 2 weeks, the change of weights appeared that non-steroid injection groups increase weight and steroid injection groups decreased weight hasty. after 4 weeks, weights recovered from weight before test. It was possible to explain the change of weight by type II muscle fiber increase. 2. In histological change of muscle fibers, atrophy didn't observed in test group I, because type II muscle fibers were developed well. we observed not only injury of muscle fiber and muscle atrophy but specifically grouping type I muscle fiber in test group II. normal arrangement of muscle fibers were visible in test group and type II muscle fibers increased. we could observe muscle recovery because of type II muscle fibers increase in test group IV. therefore, it was seem that type II cell was recovering through aquatic exercise.

• Journal of Korean Academy of Nursing
• /
• v.26 no.2
• /
• pp.271-280
• /
• 1996

The purpose of this study was to determine the effect of periodic walking during hindlimb suspension on the mass, relative weight, fiber type distribution and cross-sectional area of Type I and II fibers in the developing Type II plantaris muscle. To examine the effectiveness of periodic walking on mass and fiber size, the hindlimbs of young female Wistar rats were suspended (HS group) and half of these rats walked on a treadmill for 45 min／day(15 min every 4 hours) at 5 meters／min at a 15 degree grade(HS-W group) After seven days of hindlimb suspension, the plantaris muscle wet weight was 28.40％ significantly smaller（P＜0.005） and relative plantaris muscle weight was 26.97％ smaller compared with those of control rats（P＜0.05）. The plantaris muscle wet weight and the relative plantaris muscle weight increased by 46.60％ and 49.23％ respectively with periodic walking, moreover. the plantaris muscle wet weight and the relative plantaris muscle weight of the HS-W rats recovered to the level of the control rats. No change was observed in fiber type percentage of the developing plantaris muscle following one week of hindlimb suspension or periodic walking during hindlimb suspension. Type I and II fiber cross-sectional areas of the developing plantaris muscle were 42.51％ and 43. 68％ lower in the HS group than in the control group（p＜0.0001）, Type I and II fiber cross-sectional areas of the developing plantaris were 30.82％ and 45.97％ greater in the HS-W group than in the HS group（p＜0.0001）, whereas Type I and II fiber cross-sectional area of HS-W group were less than those of the control group（P＜0.0001） The results suggest that periodic walking can attenuate developing plantaris muscle atrophy induced by hindlimb suspension.

• The Journal of Korean Physical Therapy
• /
• v.27 no.3
• /
• pp.129-134
• /
• 2015

Purpose: The purpose of this study was to determine the influence of WBV exercise on CMJ and quadriceps muscle activation according to different frequency of vibration in soccer player and also to find effective frequency for leading appropriate treatment reaction. Methods: Thirty three subjects were randomly divided into three groups: the three groups are WBV group using 20 Hz frequency, WBV group using 30 Hz frequency and squat exercise group according to training method. The exercise program was conducted for six weeks. Subjects were measured on CMJ and quadriceps muscle activation. Results: Significant difference in CMJ was observed in the group I, II compared with the group III (p<0.05). Results of post-hoc, showed a significant difference in CMJ in on group I, II compared with the group III, but no a statistically significant difference between group I and II. Significant difference in quadriceps muscle activation was observed in the group I, II compared with the group III (p<0.05, p<0.01). Results of post-hoc, significant difference in quadriceps muscle activation in on group I, II compared with the group III and significant difference between group I and group II. Conclusion: This research intervened WBV for soccer players and compared the differences of CMJ and quadriceps muscle activation; as a result of the effective frequency for improving performance, there is a significant difference in CMJ and quadriceps muscle activation of WBV group with comparison of control group; and it was proved that WBV is effective using 30 Hz frequency for improving quadriceps muscle activation.

• Molecules and Cells
• /
• v.20 no.2
• /
• pp.263-270
• /
• 2005

Transactivation of EGF-receptor (EGFR) by G-protein coupled receptors (GPCRs) is emerging as an important pathway in cell proliferation, which plays a crucial role in the development of atherosclerotic lesion. Angiotensin II (Ang II) has been identified to have a major role in the formation of atherosclerotic lesions, although the underlying mechanisms remain largely unclear. We hypothesize that Ang II promotes the proliferation and migration of smooth muscle cells through the release of heparin-binding epidermal growth factor like growth factor (HB-EGF), transactivation of EGFR and activation of Akt and Erk 1/2, with matrix metalloproteases (MMPs) playing a dispensable role. Primary rat aortic smooth muscle cells were used in this study. Smooth muscle cells rendered quiescent by serum deprivation for 12 h were treated with Ang II (100 nM) in the presence of either GM6001 ($20{\mu}M$), a specific inhibitor of MMPs or AG1478 ($10{\mu}M$), an inhibitor of EGFR. The levels of phosphorylation of EGFR, Akt and Erk 1/2 were assessed in the cell lysates. Inhibition of MMPs by GM6001 significantly attenuated Ang II-stimulated phosphorylation of EGFR, suggesting that MMPs may be involved in the transactivation of EGFR by Ang II receptor. Furthermore Ang II-stimulated proliferation and migration of smooth muscle cells were significantly blunted by inhibiting MMPs and EGFR and applying HB-EGF neutralization antibody, indicating that MMPs, HB-EGF and EGFR activation is necessary for Ang-II stimulated migration and proliferation of smooth muscle cells. Our results suggest that inhibition of MMPs may represent one of the strategies to counter the mitogenic and motogenic effects of Ang II on smooth muscle cells and thereby prevent the formation and development of atherosclerotic lesions.

• The Journal of Korean Physical Therapy
• /
• v.25 no.5
• /
• pp.266-272
• /
• 2013

Purpose: The purpose of this study was to determine the influence of whole body vibration (WBV) exercise on balance and lower extremity muscle activity according to different intensity of vibration in stroke patients. Methods: Thirty subjects were randomly divided into three groups: experimental group II (n=10), III (n=10), and control group I (n=10). Each subject was exposed to three WBV conditions, as follows: 1. no WBV (group I), 2. 10 Hz (group II), 3. 30 Hz (group III) in semi squat position. The exercise program was conducted for six weeks (five times per week; 16 minutes per day). Subjects were measured on balance (limited of stability: LOS) and lower extremity muscle activity. Results: Significant difference in balance and lower extremity muscle activity was observed in the experimental group (II, III), compared with the control group (I). Results of post-hoc analysis, showed a significant difference in balance (LOS) in on group II and group III compared with group I, but no significant difference in on group II compared with group III, and a significant difference in lower extremity muscle activity in on group II and group III compared with group I, and a significant difference on in group II compared with group III. Conclusion: WBV exercise may be helpful in improvement of balance and lower extremity muscle activity in stroke patients.

• Journal of Korean Academy of Nursing
• /
• v.36 no.7
• /
• pp.1232-1241
• /
• 2006

Purpose: The purpose of this study was to examine the effects of cerebral ischemia on Type I(soleus) and Type II(plantaris, gastrocnemius) muscles, and to determine the effects of isometric contraction training by electro- stimulation on Type I and II muscles in cerebral ischemia model rats. Method: Twenty-five male Sprague-Dawley rats were randomly divided into four groups: ST(stroke), STES(stroke+electrostimulation), SH(sham) and SHES (sham+electrostimulation). The ST and STES groups received a transient right middle cerebral artery occlusion operation. The SH and SHES groups received a sham operation. The STES and SHES groups had daily isometric contraction training by electrostimulation(100Hz, 45mA, 7.5V) on hindlimb muscles for 7days. Result: Plantaris and gastrocenmius muscle weight, myofibrillar protein contents of soleus and gastrocnemius, and the muscle fiber cross-sectional area of gastrocnemius in the ST group significantly decreased compared with the SH group. Soleus, plantaris, gastrocnemius muscle weight, myofibrillar protein contents of soleus and gastrocnemius, and the Type I muscle fiber cross-sectional area of soleus and the Type II muscle fiber cross-sectional area of gastrocnemius in the STES group significantly increased compared with the 57 group. Conclusion: Hindlimb muscle atrophy occurs after acute stroke and isometric contraction training by electrostimulation during early stages of a stroke attenuates muscle atrophy of Type I and Type II muscles.

• Journal of Korean Academy of Nursing
• /
• v.32 no.5
• /
• pp.727-734
• /
• 2002

This study was to determine the effect of DHEA administration before, during, and after dexamethasone treatment on body weight and TypeI,II muscle weight of rat receiving dexamethasone treatment. Method: Wistar rats were divided into 6 groups: control(C), dexamethasone(D), DHEA administration for 3days after dexamethasone treatment for 7days(7D+3DH), dexamethasone treatment for 7days after DHEA administration for 3days(3DH+7D), DHEA administration during dexamethasone treatment for 4days after dexamethasone treatment for 3days(3D+4DDH), DHEA administration during dexamethasone treatment for 7days(7DDH). Dexamethasone was injected by subcutaneously daily at a dose of 5mg/kg. DHEA was orally administered daily at a dose of 5mg/kg for 7 days. Soleus(TypeI) muscle, and both plantaris and gastro- cnemius(TypeII) muscles were dissected on the 7th day of experiment. Result: Body weight of both 3DH+7D group and 3D+4DDH group increased significantly compared with that of 7D group. Body weight of 7D+3DH group decreased significantly compared with that of 7D group, 7DDH group, 3DH+7D group and 3D+4DDH group. Muscle weight of both plantaris and gastro- cnemius tended to decrease compared with that of 7D group. Muscle weight of 7DDH group, 3D+4DDH group and 3DH+7D group increased significantly compared with that of 7D+3DH group. Muscle weight of gastrocnemius of both 3DH+7D group and 3D+4DDH group increased significantly compared with that of 7D group. Conclusion: Based on these results, it can be suggested that DHEA administration before and during dexamethasone treatment can increase both body weight and mass of atrophied TypeII muscle induced by dexa- methasone treatment.

• Journal of Korean Biological Nursing Science
• /
• v.4 no.2
• /
• pp.19-40
• /
• 2002

The purpose of this study was to determine the effect of DHEA on Type I(soleus) and II muscles(plantaris, gastrocnemius) in a focal brain ischemia model rat. Thirty-seven male Sprague-Dawley rats with $200{\sim}250g$ body weights were randomly divided into four groups : CINS(cerebral ischemia + normal saline), CIDH(cerebral ischemia + DHEA), SHNS(sham + normal saline), SHDH (sham + DHEA). Both the CINS and CIDH groups were undergone a transient right middle cerebral artery occlusion operation. In the SHNS and SHDH groups, a sham operation was done. DHEA was administered daily at a dose of 0.34mmol/kg, and normal saline was administered daily at the same dose by intraperitoneal injection for 7days after operation. Cerebral infarction in the CINS and CIDH groups was identified by staining with 2% triphenyltetrazolium chloride solution for 60 minutes. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. The results were summarized as follows: 1) The muscle weights of soleus(Type I), plantaris and gastrocnemius(Type II) in CINS group were significantly less than those of the SHNS group(p<.01). The muscle fiber cross-sectional area of the CINS group was significantly less than that of the SHNS group in Type I muscle fiber of the soleus and Type II muscle fiber of the plantaris and gastrocnemius(p<.05). The myofibrillar protein content of the CINS group was significantly less than that of the SHNS group in the left gastrocnemius and right soleus(p<.05). 2) The muscle weights of the soleus, plantaris and gastrocnemius except the unaffected side of the plantaris in the CIDH significantly increased compared to those of the CINS group(p<.05). The muscle fiber cross-sectional area of the CIDH group significantly increased compared to that of the CINS group in Type II muscle fiber of the plantaris and gastrocnemius(p<.05). The myofibrillar protein content of the CIDH group significantly increased compared to that of the CINS group in the left soleus(p<.05). 3) On the post-op 8 day, the body weight of the CINS group was significantly less than that of the CIDH, SHNS and SHDH groups(p<.01). Total diet intake of the CINS and CIDH groups was significantly less than that of the SHNS and SHDH groups(p<.01). Based on these results, it was identified that muscle atrophy could be induced during the 7 days after cerebral infarction, and DHEA administration during the early stage of cerebral infarction might attenuate muscle atrophy.

• The Journal of Korean Physical Therapy
• /
• v.27 no.4
• /
• pp.190-195
• /
• 2015

Purpose: The aim of this study was to determine the effects of isokinetic eccentric training (IET) on lower extremity muscle activation and walking velocity according to slow velocity and fast velocity of isokinetic eccentric training in stroke patients. Methods: Thirty subjects were randomly divided into three groups: experimental group I (n=10), group II (n=10), and control group III (n=10). Each group was provided intervention under three conditions, as follows: isokinetic eccentric training + slow velocity (group I), isokinetic eccentric training + fast velocity (group II), and sit to stand training (group III). The training program was conducted for eight weeks (five times per week; 30 minutes per day). Subjects were measured on lower extremity muscle (vastus lateralis, vastus medialis, gastrocnemius) activation and walking velocity. Analysis of covariance (ANCOVA) were performed for comparison of lower extremity muscle activation and walking velocity between different intervention methods. Results: Significant difference in lower extremity muscle activation and walking velocity was observed in experimental group I and group II compared with the control group III (p<0.01). Results of post-hoc analysis showed a significant in lower extremity muscle activation and walking velocity in group I compared with group II and group III. Conclusion: Findings of this study suggest that slow velocity and fast velocity using isokinetic eccentric training may have a beneficial effect on improvement of lower extremity muscle activation and walking velocity in stroke patients.

• The korean journal of orthodontics
• /
• v.18 no.1 s.25
• /
• pp.89-104
• /
• 1988

This study was performed to investigate the relationships between the EMG activity of the masticatory muscles in Angle's Class II div. 1 malocclusion and normal occlusion. This study was ranged from age 12 to 14 year-old for 30 male subjects: 15 subjects were Angle's Class II div. 1 malocclusion, and 15 subjects were normal occlusion with acceptable profile. Their cephalometric measurement were analyzed, and the EMG recordings from the anterior temporal, posterior temporal, masseter, and orbicularis oris muscles were analyzed during rest position, mastication of peanuts, and swallowing. All data was recorded and statistically processed with the VAX-11/780 computer system. The results were as follows: 1. The activity of muscles at rest was highest in the posterior temporal muscle with normal occlusion, as well as in those with Class II div. 1 malocclusion, and the posterior temporal muscle activity of Class II div. 1 malocclusion was higher than that of normal occlusion. 2. During mastication, all muscle activities of Class II div. 1 malocclusion were recorded lower than those of normal occlusion, and the activity of the anterior temporal muscle was higher than that of the posterior temporal muscle in both types of occlusion. 3. As for the activity in orbicularis oris muscle, it was greater in opening phase than in closing phase during chewing cycle with both types of occlusion. 4. During swallowing, the activities of the anterior temporal, masseter, and orbicularis oris muscles of Class II div. 1 malocclusion were recorded lower than those of normal occlusion.