• 대한물리의학회지
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• 제5권3호
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• pp.395-404
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• 2010

Purpose : The object of this study was to examine the effect of motor learning on brain activation depending on the method of motor learning. Methods : The brain activation was measured in 9 men by fMRI. The subjects were divided into the following groups depending on the method of motor learning: actually practice (AP, n=3) group, action observation (AO, n=3) group and motor imagery (MI, n=3) group. In order to examine the effect of motor learning depending on the method of motor learning, the brain activation data were measured during learning. For the investigation of brain activation, fMRI was conducted. Results : The results of brain activation measured before and during learning were as follows; (1) During learning, the AP group showed the activation in the following areas: primary motor area located in precentral gyrus, somatosensory area located in postcentral gyrus, supplemental motor area and prefrontal association area located in precentral gyrus, middle frontal gyrus and superior frontal gyrus, speech area located in superior temporal gyrus and middle temporal gyrus, Broca's area located in inferior parietal lobe and somatosensory association area of precuneus; (2) During learning, the AD groups showed the activation in the following areas: primary motor area located in precentral gyrus, prefrontal association area located in middle frontal gyrus and superior frontal gyrus, speech area and supplemental motor area located in superior temporal gyrus and middle temporal gyrus, Broca's area located in inferior parietal lobe, somatosensory area and primary motor area located in precentral gyrus of right cerebrum and left cerebrum, and somatosensory association area located in precuneus; and (3) During learning, the MI group showed activation in the following areas: speech area located in superior temporal gyrus, supplemental area, and somatosensory association area located in precuneus. Conclusion : Given the results above, in this study, the action observation was suggested as an alternative to motor learning through actual practice in serial reaction time task of motor learning. It showed the similar results to the actual practice in brain activation which were obtained using activation of mirror neuron. This result suggests that the brain activation occurred by the activation of mirror neuron, which was observed during action observation. The mirror neurons are located in primary motor area, somatosensory area, premotor area, supplemental motor area and somatosensory association area. In sum, when we plan a training program through physiotherapy to increase the effect during reeducation of movement, the action observation as well as best resting is necessary in increasing the effect of motor learning with the patients who cannot be engaged in actual practice.

• The Journal of Korean Physical Therapy
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• 제28권6호
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• pp.398-407
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• 2016

Purpose: The purpose of this study was to examine the changes in electroencephalogram (EEG) coherence and brain wave activity for first-person perspective action observation (1AO) and third-person perspective action observation (3AO) of healthy subjects. Methods: Thirty healthy subjects participated in this study. EEG was simultaneously recorded during the Relax period, the 1AO, and the 3AO, with event-related desynchronization (ERD) and coherence connectivity process calculations for brain wave (alpha, beta and mu) rhythms in relation to the baseline. Results: Participants showed increased coherence in beta wave activity in the frontal and central areas (p<0.05), during the 1AO using right-hand activity. Conversely, the coherence of the alpha wave decreased statistically significantly decreased in the frontocentral and parieto-occipital networks during the observation of the 1AO and the 3AO. The ERD values were larger than 40% for both central regions but were slightly higher for the C4 central region. The high relative power of the alpha wave during 1AO and 3AO was statistically significantly decreased in the frontal, central, parietal, and occipital regions. However, the relative power of the beta wave during 1AO and 3AO was statistically significantly increased in the parietal and occipital regions. Especially during 1AO, the relative power of the beta wave in the C3 area was statistically significantly increased (p<0.05). Conclusion: These findings suggest that 1AO and 3AO action observations are relevant to modifications of specific brain wave coherence and ERD values. EEG cortical activity during action observation may contribute to neural reorganization and to adaptive neuroplasticity in clinical intervention.

• The Journal of Korean Physical Therapy
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• 제32권5호
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• pp.307-311
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• 2020

Purpose: This study examined the effects of changes in the intensity of Functional Electrical Stimulation (FES) on CorticoMuscular Coherence (CMC) during action observation. This paper presents a neurophysiological basis for the effective intensity of FES. Methods: Twenty-seven healthy volunteers were asked to observed a video with FES. The FES was provided with a sensory stimulation level, nerve stimulation level, and motor stimulation level. Simultaneously, an electroencephalogram (EEG) of the sensorimotor cortex and electromyogram (EMG) from the wrist extensor muscle were recorded. The peak CMC and average CMC were analyzed to compare the differences caused by the FES intensity. Results: The peak CMC showed a significant increase in the alpha band during motor stimulation (p<0.05). The average CMC showed a significant increase in the beta band during motor stimulation (p<0.05). Conclusion: The intensity of FES, which causes actual movement, increased the CMC during action observation. These results show that the intensity of the FES can affect the functional connection between the sensorimotor cortex and muscle.

• The Journal of Korean Physical Therapy
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• 제13권1호
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• pp.237-243
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• 2001

Skeletal muscle cells are activated by ${\alpha}$-motorneurons which release acetylcholine at the neuromuscular junction. This results in a local depolarization of surface membrane which triggers an action potential. The action potential propagates along the surface membrane and also into the T-tubule system. In the triads T-tubules are in close connection with the terminal cisternae of the sarcoplasmic reticulum(SR). The action potential activaies T-tubule voltage sensors(DHP receptors). which activates SR Ca$^{2+}$ release channels(ryanodinc receptors). Ca$^{2+}$ have a key role in skeletal muscle in that an increase of free myoplasmic Ca$^{2+}$ concentration. The process of coupling chemical and electrical signals at the cell surface to the intracellular release of Ca$^{2+}$and ultimate contraction of muscle fibers is termed excitation-contraction coupling(ECC). Coupling of cel1 surface signals to intracellular Ca$^{2+}$ release proceeds by several mechanisms in skeletal muscle cells. This review focus on sarcopiasmic reticulum(SR) Ca$^{2+}$ releasing mechanisms from sarcoplasmic reticulum in the skeletal muscle. The mechanisms include DCCR, CICR, and HCR.

• 대한물리치료과학회지
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• 제11권1호
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• pp.28-35
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• 2004

The purpose of the present study was to investigate the effectiveness of silver spike point (SSP) low frequency electrical stimulation on glomerular filtration rate (GFR), specifically, such as diuretic action in 24 hour urine and in plasma analysis from normal volunteer. The current of 1 Hz continue type (CT) of SSP low frequency electrical stimulation significantly decreased in plasma creatine from normal volunteer. However, the urine creatinine clearance (Ccr) was significantly increased by SSP low frequency electrical stimulation in normal volunteer. These results suggest that the SSP low frequency electrical stimulation, especially current of 1 Hz continue type, significantly regulates urine creatinine clearance and glomerular filtration rate from normal volunteer. Therefore, the SSP low frequency electrical stimulation is a good regulator through a diuretic action of hypertension.

• The Journal of Korean Physical Therapy
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• 제20권3호
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• pp.9-18
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• 2008

Purpose: We determined the effect of global synkinesis(GS) on gait ability, muscle contraction, and central neuron action potentials in post-stroke hemiplegic subjects. Methods: Thirty hemiplegia patients were evaluated for walking ability, muscle contraction, central neuron action potential, and comparing differences between the H-GS(high-global synkinesis) group and L-GS(low-global synkinesis) group. To obtain the GS level, surface electromyography(EMG) data were digitized and processed to root mean square(RMS). Walking ability was tested with a modified motor assessment scale(MMAS), a 10 m walking test, timed up and go(TUG) test, and a Fugl-Meyer assessment(FMA). Muscle contraction ability was measured as maximal isometric contraction(MIC) peak, MIC slope, and MIC ramp up using mechanomyography(MMG). Central neuron action potential was measured as the H/Mmax ratio or V/Mmax ratio using EMG. The data were analyzed with t-tests to determine the statistical significance. Results: MMAS(p<0.01), 10 m walking velocity(p<0.01), TUG(p<0.01), FMA-HKA(Hip, Knee, Ankle)(p<0.05), FMA-coordination(p<0.05), MIC peak (p<0.05), MIC slope(p<0.01), and MIC ramp up(p<0.05) were significantly different between H-GS and L-GS, as was the V/Mmax ratio(p<0.05), but H/Mmax was not. Conclusion: Lower GS levels indicated better walking ability and motor function. Therefore, intervention programs should consider GS levels in gait training of chronic hemiplegia.

• 대한물리치료과학회지
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• 제12권4호
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• pp.43-55
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• 2005

This study was performed to investigate the effects of low-power Helium Neon Infra Red(He-Ne IR)laser irradiation and exercise on the regeneration of experimentally cut sciatic nerve in rats. The thrity Sprague-Dawley adult mail rats were assigned to the 6 groups : normal group(1), injured control groups(2), experimental groups(3). There was made artificial injured in the sciatic nerve of rats the each experimental laser group and exercise group were treated from 3 days after being injured for the 5 minutes(laser group), 10 minutes(exercise group), and 15 minutes(exercise and laser group) everyday during 2 weeks. There were measured the changes of amplitude of compound muscle action potential and histological change by the light microscopy on the sciatic nerve injured rats. The results obtained as follows : 1. In the control groups, the regeneration were slowly and slightlly progressed to compared with the experimental groups. Inflammation were much more observed, and fibrous adhesion was also observed around the sutured region of the cut sciatic nerve. 2. The amplitude of compound muscle action potential in the experimental groups were significantly increased to the injured control groups at 1 week(p<.05). The compound muscle action potential of the exercise and lased group was significantly decreased to be similar to normal group at 2 weeks(p<.05). 3. In histologic finding, in the experimental groups were observed the proliferation of the schwann cells, the infiltration of inflammatory cells and the extent of destruction at adjacent tissue were remarkably decreased on the 2 weeks. From these experimental results, it may be suggested that the laser and exercise were effected the heeling process of peripheral nerve injuried rats.

• 대한통합의학회지
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• 제7권3호
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• pp.171-180
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• 2019

Purpose : The purpose of this study was to investigate the difference in motor cortical excitability during mental practice and action observation in subjects with forward head posture. Methods : This study was performed in two groups, a forward head posture group (n=17) and a normal posture group (n=17). Electroencephalography (EEG) was conducted to investigate cerebral cortex activity, and six electrodes were attached to Fp1, Fp2, C1, C2, C3, and C4 to measure the relative alpha power, relative beta power, relative gamma power, and mu rhythms. The subjects were requested to perform the four different conditions, which were eye opening, eye closing, mental practice, and action observation for 300 seconds. Results : The results showed that the relative alpha waves showed a significant difference between the normal and forward head posture groups in the C1, C2, C3, and C4 regions with the eyes open (p<.05). The relative beta waves also showed a significant difference between the two groups in the Fp1 and Fp2 regions during action observation (p<.05). The relative gamma waves were significantly different between the normal and forward head posture groups in the Fp1 and Fp2 regions during action observation (p<.05) in C1, C2, and C3 with eyes closed (p<.05) and in C1, C2, C3, and C4 with eyes open (p<.05). Conclusion : The results of this study showed that EEG change in the forward head posture group was different from that in the normal control group in action observation rather than in mental practice. Therefore, we are expected to provide a neurophysiological basis for applying action observation to motor skill learning during exercise for correcting forward head posture.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.725-730
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• 2002

The durability of concrete involves resistance to freeze-thaw action, corrosion, permeation, carbonation, chemical attack and so on. Generally, properties of concrete have been well understood under the separate action of these deterioration mechanisms. However, in practice, the degradation of concrete usually is the result of combined action of physical and chemical attack and can be accelerated by the combined action of several deterioration mechanisms. In the present study, to evaluate the combined deterioration by freeze-thaw action and seawater attack, ground granulated blast-furnace slag or silica fume concrete with water or seawater as mixing water was exposed to 210 cycles of freeze-thaw action. Tests were conducted to determined the relative dynamic modulus of elasticity and compressive strength. Furthermore, The XRD, SEM and EDS analysis were performed on the deteriorated part of concrete due to freeze-thaw action and seawater attack.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.589-592
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• 2006

The durability of concrete involves resistance to freeze-thaw action, corrosion, permeation, carbonation, chemical attack and so on. Generally, properties of concrete have been well understood under the separate action of these deterioration mechanisms. However, in practice, the degradation of concrete usually is the result of combined action of physical and chemical attack and can be accelerated by the combined action of several deterioration mechanisms. In the present study, to evaluate the combined deterioration by freeze-thaw action and seawater attack, ground granulated blast-furnace slag or silica fume concrete with water or seawater as mixing water was exposed to 300 cycles of freeze-thaw action. Tests were conducted to determined the relative dynamic modulus of elasticity and compressive strength. Furthermore, The MIP analysis were performed on the deteriorated part of concrete due to freeze-thaw action and seawater attack.