• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.577-589
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• 2002

There are several variations in normal mastication. In them, unilateral mastication is chewing, predominantly on a preferred side of the dentition and hardly on e non-preferred side. Continual unilateral mastication may alter the coordination of masticatory muscles. Although they studied about these EMG of masticatory muscles, there were no information about characteristics of masticatory muscle activity in unilateral mastication. Therefore, In this study, we investigated the activity of the masseter and anterior temporal muscles during rest, clenching in maximum intercuspation and gum chewing in habitually unilateral mastication group compared with normal group and tried to know effects of continual unilateral mastication on activity of masticatory muscles. The results of this study were as follows 1. In electromyographic activity during rest, in bilateral mastication group pattern of muscle activity of right and left side was symmetrical. But, in unilateral mastication group, records of anterior part of temporal muscle was higher than that of bilateral mastication group (p<.01) and patterns of muscle activity of right and left side in both muscle were asymmetrical.(p<.05) 2. In electromyographic activity during clenching in maximum intercuspation, records of superficial part of masseter muscle were higher than anterior part of temporal muscle in both group. Muscle activity of temporal muscle in unilateral mastication group was a little higher han bilateral mastication group and asymmetry of activity pattern in temporal and masseter muscle was shown but these differences were not statistically significant. (p<.05) 3. In electromyographic activity during gum chewing, temporal muscle was activated earlier than masseter muscle and maximum bite force is derived from masseter muscle in both group. In unilateral mastication group, electromyographic activity of masseter and temporal muscle of preferred chewing side, regardless of right or left side chewing, was higher than that of bilateral mastication group and especially, difference in masseter muscle was statistically significant. (p<.01) Based on the above results, our study suggested that recording of masticatory muscle activity will be helpful in the effective diagnosis and treatment of some types of the parafunctional habits.

• Journal of Biomedical Engineering Research
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• v.13 no.1
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• pp.1-8
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• 1992

In the field of prosthesis arm control, the pattern classification of the EMG signal is a required basis process and also the estimation of force from collected EMG data is another necessary duty. But unfortunately, what we've got is not real force but an EMG signal which contains the information of force. This is the reason why we estimate the force from the EMG data. In this paper, when we handle the EMG signal to estimate the force, spatial prewhitening process is applied from which the spatial correlation between the channels are removed. And after the orthogonal transformation which is used in the force estimation process, the transformed signal Is inputed into the probabilistic model for pattern classification. To verify the different results of the multiple channels, SNR(signal to noise ratio) function is introduced.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.668-674
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• 2006

In order to develop a cell based robot, we present a micro-mechanical force measurement system for the biological muscle actuators, which utilize glucose as a power source. The proposed measurement system is composed of a micro-manipulator, a force transducer with a glass probe, a signal processor, an inverted microscope and video recording system. Using this measurement system, the contractile force and frequency of the cardiac myocytes were measured in real time and the magnitudes of the contractile force of each cardiac myocyte under different conditions were compared. From the quantitative experimental results, we could estimate that the force of cardiac myocytes is about $20\sim40{\mu}N$, and show that there are differences between the control cells and the micro-patterned cells.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.391-398
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• 2019

The purpose of study is to investigate the difference of the daN force applied during the examination using Telos Device and the degree of fluctuation of anterior cruciate ligament according to the individual differences of the muscles involved in knee stability. The examination was done by the Lachman test using Telos Device and the changes of anterior cruciate ligament were measured by varying the force of 0. 15, 30 daN on each right and left side and the force of 30 daN after the bruce protocol. Computed tomography (CT) was used to measure muscle mass. As a result of measuring the degree of fluctuation of the anterior cruciate ligament according to the change of the force applied to the Telos Device, there was a statistically significant difference in the knee fluctuation when 15 daN and 30 daN were applied on both right and left. Also, it is analyzed that the degree of fluctuation of anterior cruciate ligament varies according to the difference of individual's muscle mass. Therefore, it is considered that the force applied to the Telos Device should be changed according to the difference of individual's muscle mass.

• Journal of the Ergonomics Society of Korea
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• v.21 no.2
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• pp.25-33
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• 2002

The purpose of study is to investigate the relationship between the trunk muscle fatigue and recovery time during repetitive extension by using a surface electromyogram(EMG). Ten healthy subjects particioated in a simulated lifting task with five levels of recovery time and three levels of sub-maximal contraction. EMG signals of the L1(Lumbar 1st Vertebrae) and L3(Lumbar 3rd Vertebrae) level of the erector spinae muscle were recorded. and analyzed in terms of MPF(mean power frequency) parameter to quantify the level of muscle fatigue. It was found that MPF significantly (p<0.05) decreased during repetitive extension task at 50% and 75% sub-maximal contractions. Then it took minutes for the trunk muscle to recover from fatigue during 50% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. The recovery time estimated by the maximum force needs to be re-evaluated for the trunk muscle to fully recover from fatigue. In conclusion. the work/rest cycle needs to be studied based upon the information of muscle fatigue in order to prevent workers from musculoskeletal injuries during repetitive lifting task.

• The Journal of Internal Korean Medicine
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• v.11 no.1
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• pp.77-91
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• 1990

This study was carried out to investigate the effect of Jasoeumja extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate its mechanism. The results were obtained as follows: 1. The isolated trachea smooth muscle was suspended in the Organ bath with oxygenated Kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recorded with Isometric transducer (Nacro F-60). The resting tension was approximately 0.5g. 2. The trachea smooth muscle of the isolated guinea pig was significantly relaxed by the administration of Jasoeumja extract. 3. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine $10^{-4}M$ was significantly inhibited by Jasoeumja extract. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine $10^{-4}M$ was considerably inhibited by Jasoeumja extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig to 5-hydroxytryptamine $10^{-4}M$ was considerably inhibited by Jasoeumja extract.

• The Journal of Internal Korean Medicine
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• v.11 no.2
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• pp.68-79
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• 1990

This study was carried out to investigate the effect of Heapyoyangjintang and Haepyoejintang extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate its mechanism. The results were obtained as follows : 1. The isolated trachea smooth muscle was suspended in the organ bath with oxygenated kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recorded with Isometric transducer(nacro F-60). The resting tension was approximately 0.5g. 2. The trachea smooth muscle of the isolated guinea pig was significantly relaxed by the administration of Haepyoyangjintang and Haepyoejintang extract. 3. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine$10^4M$ Was significantly inhibited by Heapyoyangjintang and Haepyoejintang extract. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine$10^4M$ was considerably inhibited by Haepyoyangjintang and Haepyoejintang extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig to 5-hydorxytrtrypptamine $10^4M$ was considerably inhibited by Haepyoyangjintang and haepyoejintang extract.

• The Journal of Internal Korean Medicine
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• v.13 no.2
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• pp.84-94
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• 1992

This study was carried out to investigate the effect of samyootang and shinchulsan extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate it's mechanism The isolated were obtained as follows ; 1. The isolated trachea smooth muscle was suspended in the organ bath with oxygenated kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recored with Isometric transducer (nacro F-60) The resting tension was approximately 0.5g 2. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine $10^{-4}M$ was significantly inhibited by samyootang and shinchulsan extract. 3. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine $10^{-4}M$ was considerably inhibited by samyootang and shinchulsan extract. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig to histamine $10^{-4}M$ was significantly inhibited by samyootang and shinchulsan extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig to acetylcholine $10^{-4}M$ was significantly inhibited by samyootang and shinchulsan extract.

• The Journal of Korean Physical Therapy
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• v.23 no.5
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• pp.1-5
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• 2011

Purpose: This study was designed to investigate the changes of postural sway and muscle activation while standing upright and performing a dual task. Methods: Nine healthy adults were recruited and provided their written informed consent. They performed a balance task with and without a cognitive task on a force flatform (Good balance, Metitur Ltd., Filand). Postural sway was measured as medio-lateral and anterior-posterior distance and the velocity of the center of pressure and muscle activations of the ankle dorsi- and plantar-muscle was measured. The recruits completed three trials and the data was analyzed by a paired t-test. Results: There were significant differences in the medio-lateral and anterior-posterior distance and the velocity of the center of pressure, and significant increases in the muscle activities of the tibialis anterior. Conclusion: These findings revealed that performing a dual task increases postural sway and muscle activation of the ankle when simultaneously maintaining balance and performing another cognitive task. Future studies should focus on balance training with a dual task for patients.

• Food Science of Animal Resources
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• v.39 no.2
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• pp.197-208
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• 2019

The aim of this study was to investigate the relation of sensory quality traits of cooked beef to fresh meat quality and histochemical characteristics, especially muscle bundle traits, in the longissimus thoracis muscle of Hanwoo steers. Cooking loss negatively correlated with softness, initial tenderness, chewiness, rate of breakdown (RB), and amount of perceptible residue (AR) after chewing (p<0.05), and drip loss showed negative correlation with RB and AR (p<0.05). All the attributes of tenderness exhibited negative correlation with the Warner-Bratzler shear force value (p<0.05). Marbling score and the intramuscular fat (IMF) content showed positive correlation with all the organoleptic characteristics, including tenderness attributes, juiciness, and flavor (p<0.05). Regarding histochemical characteristics, muscle fiber size did not have a significant correlation with all the sensory quality traits, although the area percentage of type I fiber was related with softness, initial tenderness, and chewiness (p<0.05). On the contrary, the characteristics of muscle bundle were related to all the sensory tenderness attributes (p<0.05), and the sensory tenderness increased with smaller muscle bundle size (p<0.05). These results suggest that the IMF content and bundle characteristics can be used as indicators for explaining the variations in sensory tenderness in well-marbled beef.