• Journal of Yeungnam Medical Science
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• v.22 no.2
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• pp.119-130
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• 2005

Stroke is a leading cause of chronic physical disability. The recent randomized controlled trials have that motor function of chronic stroke survivors could be improved through physical or pharmacologic intervention in the stroke rehabilitation setting. In addition, several functional neuroimaging techniques have recently developed, it is available to study the functional topography of sensorimotor area of the brain. However, the mechanisms involved in motor recovery after stroke, are still poorly understood. Four motor recovery mechanisms have been suggested, such as reorganization into areas adjacent to the injured primary motor cortex (M1), unmasking of the motor pathway from the unaffected motor cortex to the affected hand, attribution of secondary motor areas, and recovery of the damaged contralateral corticospinal tract. Understanding the motor recovery mechanisms would provide neurorehabilitation specialists with more information to allow for precise prognosis and therapeutic strategies based on the scientific evidence; this may help promote recovery of motor function. This review introduces several methodologies for neuroimaging techniques and discusses theoretical issues that impact interpretation of functional imaging studies of motor recovery after stroke. Perspectives, for future research are presented.

• Journal of Korean Physical Therapy Science
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• v.7 no.1
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• pp.333-352
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• 2000

The objective of this study was to identify the effects of the cognitive performance of stroke patients on their motor function recovery after comprehensive rehabilitation management. The subjects of this study were 41 stroke in-patients of the Rehabilitation Hospital, College of Medicine, Yonsei University, hospitalized during the period from September 1, 1997 to May 5, 1998. The cognitive performance was measured using a Mini-Mental State Examination(MMSE) and the motor function recovery using Motor Assessment Scale(MAS). The data were analyzed by the paired t-test, independent t-test, a one way ANOVA, and Pearson's correlation coefficiency. The findings were as follows: 1. There was a significant difference found in the motor function recovery level after the comprehensive rehabilitation management. 2. There was no significant difference found in relation to sex, age, cause of stroke, laterality of paralysis and the level of spasticity. However, there was a big difference between pre- and post-treatment regarding the treatment period. 3. In line with the cognitive performance level, there was a significant difference found in the motor function recovery level after the comprehensive rehabilitation management. 4. The correlation between the elements of the cognitive performance and the motor recovery was found to be high in orientation, attention, calculation, and language. Those elements were expected to give larger effects on motor recovery after the comprehensive rehabilitation management. Based on this study, the cognitive performance level was found to play an important role in bringing effects on motor recovery after the comprehensive rehabilitation management of stroke patients. And the evaluation on the motor recovery based on quality would be also expected to be examined, as well as the cognitive performance level test accompanied by Intelligence Quality(IQ) test.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.3
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• pp.178-182
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• 2016

FIDVR(Fault Induced Delayed Voltage Recovery) is a phenomenon that recovery of the system voltage level delays after the fault. Cause of FIDVR phenomenon is motor load characteristic about voltage and reactive power. In low voltage condition, the motor go to stall state that consume large amount of reactive power. As a result, the voltage recovery problem is that of repeated occurrences of sustained low voltage following faults on the system. In this paper, analysis the characteristics of the motor load. And using the korean power system actual data, perform a case studies to voltage delay recovery phenomenon alleviation method. Change of each parameters by analyzing the effect on system and selecting an influence parameter. In addition, dynamic characteristic analysis of the resulting difference in the proportion by the motor load in power systems, considering the effect on the voltage stability.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.1
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• pp.1-6
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• 2016

Recently, proportion of the induction motor load is gradually increased. When a contingency in the power systems, it has been discovered phenomenon that the voltage is delayed recover caused mechanical characteristics of the induction motor load. It can be a serious impact on the voltage stability of the power system considering induction motor load. The scheme to mitigate this phenomenon tripping off the motors to prevent voltage drop and delayed voltage recovery on the load demand side. Fault induced delayed voltage recovery phenomenon is caused by stalling of small induction motor load in transmission level contingencies. In this paper, fault induced delayed voltage recovery phenomenon mitigation method implementation under voltage load shedding on the korean power system considering induction motor load.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.4
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• pp.559-567
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• 2010

Purpose : The purpose of this study is to investigate the effects of motor function recovery and change of the heart function factors(ECG & Troponin I) with ischemic stroke patients by different amounts(times) exercise. Methods : Forty-six consecutive chronic hemiparetic patients with cerebral infarct were randomly assigned to two groups: Group 1 (exercise time 60 minutes/day) and Group 2 (exercise time 120 minutes/day). Types of exercise included static bicycle, isokinetic exercise, and standing or gait exercise on a treadmill. Outcome measures included the level of motor recovery (Fugl-Meyer Scale, FMS) and heart function (ECG and Troponin I), and measurements were performed three times: pre-test, 8 weeks and 12 weeks. Results : There was a significantly different change of motor function recovery and ECG between two groups during treatment period. Especially there were significantly change period of pre-test to 8 weeks on ECG and pre-test to 12 weeks on motor function recovery. But Troponin I has no significantly different change between two groups during treatment period. Also there was no significantly different change of motor function recovery and ECG and Troponin I with between two groups during treatment period. Conclusion : The exercise program improved motor function and change ECG without Troponin I in two groups. The result of this study shows that no matter how different amounts of exercise to effect of motor function recovery and heart function test in chronic patients with cerebral infarct.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.53-58
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• 2010

Purpose: Our goal was to determine the difference in motor recovery between two stroke types: the corona radiata (CR) infarct type and the intracerebral hemorrhage (ICH) type, by using assessment methods for motor functions. Methods: Forty subjects who were diagnosed as having had a stroke with an infarct (men: 11, women: 9, mean age: $62.25{\pm}7.59$) or a stroke with an ICH (men: 12, women: 8, mean age: $59.75{\pm}6.11$) were recruited. In all subjects, motor functions of the affected extremities were measured 2 times: at stroke onset (initial) and 6 months after the onset (final) by the motricity index (MI), the modified Brunnstrom classification (MBC), and functional ambulatory category (FAC). We compared the final assessment with the initial one. Results: Motor functions of all patients improved with the passing of time. All scores of motor function assessment in the ICH type were higher than in the infarct type. Comparing the initial assessment with the final one, upper MI and MBC scores of the upper extremities were significantly different between the two stroke types (p<0.05), but lower MI and FAC scores of the lower extremities were not (p>0.05). Conclusion: These findings imply that patterns of motor recovery in patients with either the infarct type or the ICH type of stroke change for the better over time. The degree of motor recovery in the ICH type was better than in the infarct type. Therefore, one can introduce clinical interventions by the aspect of progress in functional motor recovery.

• Journal of Oriental Neuropsychiatry
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• v.13 no.2
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• pp.101-106
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• 2002

Objectives : The degree of post-stroke depression was observed and then correlated to the recovery rate of the motor functions of the above treated stroke patients. Methods : The BDI SCALE(Beck Depression Inventory Scale) and motor grades of 50 diagnosed stroke patients who were hospitalized in Dong-Seo Oriental Hospital between the period of May 2002 to September 2002 were measured. After a 1 month recovery period the BDI SCALE and motor grade of the above mentioned patients were again measured and a correlation was observed. Results : A lower BDI SCALE was observed in patients with a higher motor grade recovery rate. Conclusion : The treatment of post-stroke depression is imperative for positive effects on the motor functions of stroke patients.

• PNF and Movement
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• v.21 no.3
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• pp.327-335
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• 2023

Purpose: Cerebellar injury can be caused by a variety of factors, including trauma, stroke, and tumor. Cerebellar injury can manifest in different clinical symptoms and signs depending on the size and location of the injury. The purpose of this study was to examine and compare the recovery patterns of each motor function by tracking the motor levels of patients with cerebellar injury. Methods: This study recruited 11 patients with quadriplegia resulting from cerebellar injury. The motricity index (MI), modified Brunnstrom classification (MBC), and functional ambulation category (FAC) methods were used to evaluate motor levels. The motor function evaluation was performed immediately after the onset of the condition and at intervals of one month, two months, and six months after onset. Results: The MI values of the upper and lower extremities and hand function (MBC) indicated severe paralysis in the early stages of onset. Compared to the onset time, significant motor function recovery was observed after 1, 2, and 6 months (p < 0.05). In contrast, there was no significant pattern of recovery between 1, 2, and 6 months after onset (p > 0.05). FAC indicated showed significant recovery at one month compared to onset (p<0.05), and there was also a significant difference between 1 and 2 months (p < 0.05). On the other hand, there was no significant difference in FAC between 2 and 6 months (p > 0.05). Conclusion: Patients with cerebellar injury showed significant recovery in functions related to muscle strength and voluntary muscle control one month after onset and gradually recovered further over the next six months. On the other hand, gait function, which is closely related to balance, showed a relatively slow recovery pattern from the beginning of the disease to the six month follow-up.

• Journal of Korean Institute of Industrial Engineers
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• v.5 no.2
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• pp.21-36
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• 1979

Static muscle contractions when prolonged or frequently repeated result in discomfort, fatigue, and musculosketal injuries. An analytic and quantitative model has been developed in order to expand the working knowledge on muscle fatigue. In this paper, three Markov models of muscle fatigue are developed. These models are based on motor unit fatigue-recovery characteristics obtained from information on motor unit behavior as it relates to fatigue and graded exertions. Three successively more realistic models are developed that involve: (1) homogeneous motor units with intensity-dependent fatigue rates and state-independent recovery rates (the HMSI model); (2) homogeneous motor units, intensity-dependent fatigue rates and state-dependent recovery rates (the HMSD model); and (3) non-homogeneous motor units (i.e., Type S and Type F), intensity-dependent fatigue rates and state-dependent recovery rates (the HMSD model). The result indicate that a simple stochastic model provide a means to analyze the complex nature of muscle fatigue in sequential static exertions.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.60-67
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• 2018

The presence of induction motor loads in a power system may cause the phenomenon of delayed voltage recovery after the occurrence of a severe fault. A high proportion of induction motor loads in the power system can be a significant influence on the voltage stability of the system. This problem referred to as FIDVR(Fault Induced Delayed Voltage Recovery) is commonly caused by stall of small HVAC unit(Heating, Ventilation, and Air Conditioner) after transmission or distribution system failure. This delayed voltage recovery arises from the dynamic characteristics associated with the kinetic energy of the induction motor load. This paper proposes the UVLS (Under Voltage Load Shedding) control strategy for dealing with FIDVR. UVLS based schemes prevent voltage instability by shedding the load and can help avoid major economic losses due to wide-ranging cascading outages. This paper review recent topic about under voltage load shedding and compare decentralized load shedding scheme with conventional load shedding scheme. The load shedding strategy is applied to an actual system in order to verify the proposed FIDVR mitigation solution. Simulations demonstrate the effectiveness of the proposed method in resolving the problem of delayed voltage recovery in the Korean Power System.