• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.576-581
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• 2007

The purpose of this study is to investigate changes in the forearm-muscle fatigue of a train driver operating the MasCon by using EMG (electromyogram) measurement technique. Train drivers usually use their forearm 4hours/day for normal operation. Accordingly, few different EMG signals of deltoid, biceps brachii, brachioradialis, flexor carpi ulnaris muscle of upper extremity have been measured and analyzed. The raw EMG Signals have been converted into median frequency using spectrum analysis. As the result, 80% of 10 subjects (real train drivers) showed that median frequency value of all four muscles has been reduced after 30 minutes of train operation. This results demonstrated that operating MasCon for 30 minutes could induce muscle fatigue.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.1
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• pp.119-132
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• 2010

Objectives : The purpose of this study is to compare interrelations between stress and muscles of neck through stress response inventory(SRI), 7 zone diagnostic system and surface electromyography(sEMG). Methods : This study was carried out with the data from SRI, 7 zone diagnostic system and sEMG. First subjects were divided into two group according to the SRI points. subjects in group A had points of SRI in which lower than 30 points. Subjects in group B had points of SRI in which higher than 30 points. And subjects were divided into nonstress group(Group C) and stress grouop(Group D) according to the result of 7 zone diagnostic system. Then we investigated how to differentiate the muscle contraction, fatigue, recovery and asymmetry ratio on sEMG for each groups. Results : In this study, the muscle contraction of both upper trapezius muscle and left sternocleidomastoid muscle and left scalene muscle in stress group were higher than nonstress group significantly. And the muscle recovery of left sternocleidomastoid muscle and left scalene muscle in stress group were higher than nonstress group significantly. Conclusions : This results show that the stress was associated with muscle condition.

• Journal of Chest Surgery
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• v.23 no.1
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• pp.146-151
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• 1990

Myasthenia gravis is a disorder of neuromuscular transmission characterized by weakness and fatigue of voluntary muscles. It is now reasonably established to be due to an autoimmune attack directed against the postsynaptic nicotinic acetylcholine receptors of voluntary muscles. Thymectomy has become increasingly important in the treatment of this disease after the successful case of Blalock in 1939. From January 1984 to December 1988, we performed total thymectomy in 25 cases of myasthenia gravis except one, and get the results as follows. l. Among 25 cases, male to female was 10:15 and the age was ranged from 16 years to 65 years. 2. Thymectomy was done in 24 cases and 1 case of malignant thymoma was not resectable. 3. There were 2 deaths after thymectomy due to myasthenic crisis. 4. There were 19 cases [76 %] of improvement after thymectomy as follows; complete remission was 6 cases [24 %], marked improvement was 9 cases [36 %] and subjective improvement was 4 cases [16 %]. 5. The effect of age, and duration of disease on operative result was not statistically significant, but that of thymic pathology was significant.

• Journal of the Ergonomics Society of Korea
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• v.22 no.2
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• pp.57-69
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• 2003

This study was performed to investigate the isometric endurance time as percentages of maximum voluntary contraction. Electromyogram(EMG) and Borg's CR-I0 value were measured by push-pull-up-down tasks for 10 healthy males. The normalized EMG value and the MPF(mean power frequency) were used to estimate the muscle recruitment pattern and the development of muscle fatigue. The subjects exerted and maintained 5 levels of %MVC(maximum voluntary contraction) in $90^{\circ}$ shoulder flexion/ 180oelbow extension at sitting posture. The up-task showed the lower endurance time and higher Borg's CR-I0 value than the other task types. Comparing Rohmert's curve with the endurance time of task types. Rohmert's curve overestimated the endurance time of up-task and underestimated the endurance time of push-pull-down tasks. The normalized EMG value showed that muscles recruitment patterns were different from task types. The 4 muscles(biceps brachii muscle, tricep brachii muscle. middle deltoid muscle. trapezius muscle) recruitment patterns of up-task were higher than those of other tasks. The MPF value decreased with the endurance time, and the shift of MPF at up-task was larger than that of the other task types.

• Journal of Korean Physical Therapy Science
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• v.19 no.1
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• pp.47-54
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• 2012

Purpose : This study is to know the effect on muscle activity when people use mouse aid or not in computer working environment. Method : 11 people of both sex in their twentieth were tested. As a independent variable, the condition without mouse aid and the condition with movable mouse aid were selected, and as a dependent variable, MVC(%) on four muscles and inconvenience degree(RPE scale) on three body part(wrist, forearm, shoulder) were measured. Result : Analyzing the research, MVC(%) of extensor muscle of finger had notably higher muscle activity than other muscles, and there wasn't notable difference in muscle activity before and after using mouse aid. In case of using mouse aid, we tested by giving RPE questionnaire which segmentalized mental fatigue degree into hand, forearm, and shoulder, and resultingly, there wasn't notable differences perspectively. However, people felt less tiredness subjectively after they use the mouse aid. Conclusion : The usage of mouse aid seems to give comfort to computer users.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.195-200
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• 1998

Toinsul consists of breathing method and exercising method by stimulation of acupuncture point and meridian. It activates the circulation of energy and blood and helps excretion of noxious vapor and it improves elasticity and vitality of muscles, tendon md ligament. It sharpens both secretion of synovia .and circulation around joints and also controls the whole body through meridian. This report introduces some about the exercise methods for treatment of lumbago and shoulder joint diseases among medical, surgical and gynecological diseases. It can be used for health care, treatment, relaxation muscles and recovery from fatigue in an aspect of prevention. It has been widely used for treatment of diseases and promotion of health so far even though it is not yet demonstrated scientifically. Therefore, it should be used mere efficiently as an important part of the oriental physical therapy.

• The Journal of Korean Physical Therapy
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• v.35 no.2
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• pp.53-57
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• 2023

Purpose: The purpose of this study was to compare the changes in the muscle activation of the quadriceps muscle (rectus femoris, vastus lateralis, vastus medialis) during the stand-to-sit (StandTS) movement according to the plantar flexion angle of the ankle joint. Methods: A total of 22 healthy young females participated in this study. During the StandTS under the three conditions (plantarflexion angle 0°, 20°, and 45° of the ankle), electromyography (EMG) data (% maximum voluntary iso¬metric contraction) of the rectus femoris, vastus lateralis, and vastus medialis were recorded using a wireless surface EMG system. Results: There was a significant difference in the muscle activation of rectus femoris, vastus lateralis, and vastus medialis according to the plantar flexion angle (0°, 20°, and 45°) of the ankle. The muscle activation of the quadriceps was the highest at a 45° angle of plantarflexion and the lowest at 0°. One-way repeated ANOVA was used to analyze the muscle activation data of the lower extremity muscles according to the angle of the ankle joint. Conclusion: Based on the results of our study, it was confirmed that the muscle activity of the quadriceps can be increased even in the StandTS movement, which involves the eccentric contraction of the quadriceps muscle. This suggests that maintaining a plantar flexion posture for a long time, say by wearing high-heeled shoes, can quickly cause muscle fatigue in the lower-limb muscles, which can cause a decrease in balance ability leading to falls.

• Fashion & Textile Research Journal
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• v.11 no.6
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• pp.911-917
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• 2009

The purpose of this study was to investigate muscle activity of the lower limbs when walking in jeans in order to obtain basic information for development of new jeans patterns with excellent movement adaptability. Using three types of jeans (basic, medium, and slim) with different ease on hip, knee circumference, and crotch length, and two different types of shoes, Electromyogram (EMG) of the lower limbs muscle was measured for four healthy subjects walking on treadmills and stairs. EMG of vastus lateralis, semitendinous, tibialis anterior and medial head of gastrocnemius muscles was measured. The muscle activity was assessed in RMS (Root Mean Square) value of the EMG. On the treadmill in sneakers, only the vastus lateralis muscle showed a significant difference in RMS value depending on patterns. Basic and medium jeans allowed higher muscle activity than trunks of slim jeans did. On the treadmill in high heels and slim jeans, the RMS values of all muscles were significantly smaller than in basic jeans, whereas no significant differences were shown while in trunks or medium jeans. On the stairs either in sneakers or in high heels, no significant differences were shown between all muscle activities for all types of jeans. On the treadmill, greater fatigue was induced in all muscles from walking in high heels than in sneakers for all jeans patterns. When walking on the stairs wearing either type of shoes, however, the effect of jeans pattern on muscle activities was different from muscle to muscle.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.337-344
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• 2019

The purpose of this study men and women 20 to 30 of 16 patients wearing thick insoles 5cm before and after squat exercise based on the angle of the knee joint(0-, 60-, 90-degree) was to observe the muscle activities. For this through the analysis of the rectus femoris EMG, vatus medialis vatus lateralis, tibialis anterior, gastrocnemius MVIC were quantified using. The results following results were obtained. After wearing the thick insole standing position(0') had increased EMG activity of vastus lateralis muscle, the knee angle is rectus femoris, vatus medialis, vastus lateralis, tibialis anterior, gastrocnemius muscles were increased muscle activity. thick insole of the ankle joint, causing plantar flexion forward weight distritbution by focusing is normally the body would lead to an array. When an array of everyday life, these abnormalities increases energy consumption, and muscle fatigue, increase will cause an imbalance in the muscles. Therefore, wearing thick insoles by changing the activity of the muscles may cause knee pain.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.5
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• pp.380-388
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• 2004

This study proposed an improved spike detection algorithm which automatically detects suitable spike threshold on the amplitude of surface electromyography(SEMG) signal during isometric contraction. The EMG data from the low back muscles was obtained in six channels and the proposed signal processing algorithm is compared with the median frequency and Gabriel's spike parameter. As a result, the reliability of spike parameter was inferior to the median frequency. This fact indicates that a spike parameter is inadequate for analysis of multi-channel EMG signal. Because of uncertainty of fixed spike threshold, the improved spike detection algorithm was proposed. It automatically detects suitable spike threshold depending on the amplitude of the EMG signal, and the proposed algorithm was able to detect optimal threshold based on mCFAR(modified Constant False Alarm Rate) in the every EMG channel. In conclusion, from the reliability points of view, neither median frequency nor existing spike detection algorithm was superior to the proposed method.