• Journal of TMJ Balancing Medicine
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• v.6 no.1
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• pp.1-4
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• 2016

We investigated the potential of electromyography (EMG) for diagnosing imbalance in the temporomandibular joint (TMJ) to apply functional cerebrospinal therapy (FCST). The electromyography signals were measured in the sternocleidomastoid muscle (SCM) in patients with temporomandibular disorder (TMD) while a FCST specialist conducted a restricted cervical rotation test. In addition, we also observed the changes in the electromyography signals according to pre-treatment or treatment with a TMJ balancing appliance (TBA), a customized TMJ balancing appliance (CBA), or a CBA with one paper bar. The right SCMs of the two patients with right TMJ imbalance had high EMG signals in the right cervical rotation test, while the left SCMs showed low EMG signals in the left rotation. In addition, the high EMG signals in the right SCMs decreased when using the TBA or the CBA, but the EMG signals of the left SCMs showed low EMG values during the treatments. Furthermore, the EMG signals of the right SCMs rose again after artificial imbalance of the right TMJ by the CBA with one paper bar. This case report demonstrated the potential of EMG as an objective diagnostic method for FCST.

• The Research Journal of the Costume Culture
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• v.21 no.4
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• pp.606-611
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• 2013

It has been reported that tight sportswear could have complicated influence on physiological function of human body. The purpose of this present study was to investigate the effect of wearing gradient compression tights (GCT) on muscle strength and EMG activity during repeated isokinetic muscle contractions. Four healthy male undergraduate students performed maximal voluntary isokinetic concentric muscle contractions on biomechanical test and training systems with GCT and loose pants as control (Cont) respectively. During each test, the peak torque of extensor and flexor contractions and the surface electromyography (sEMG) of the rectus femoris and medial gastrocnemius was recorded simultaneously, the peak torque was recorded as an indicator of muscle strength, and the average amplitude and mean power frequency of sEMG were calculated as indicators of EMG activity. The results showed that: the peak torque decreased gradually during continuous muscle contractions both when the Cont and GCT were worn, average sEMG and mean power frequency declined along with the repetitions of muscle contractions for both wearing conditions, and the change tendency was consistence with that of peak torque. There was no obvious difference between the peak torque recorded wearing the Cont or wearing GCT, but when GCT were worn, average sEMG was lower and mean power frequency was higher than the Cont condition. In 24 samples obtained from four subjects, 80% of results showed the same trend. So we could make a conclusion that wearing GCT had no obvious effect on the improvement of muscle strength, but it would affect the EMG activity positivly.

• Archives of Reconstructive Microsurgery
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• v.24 no.1
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• pp.13-15
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• 2015

Purpose: Since the hand elevation test was first introduced by Ahn in 2001, it has been one of most performing provocative test for diagnosing carpal tunnel syndrome. Although many studies have been published on the hand elevation test, there are no study that can explain why false-negative results of hand elevation test appears in carpal tunnel syndrome patients diagnosed by electromyography (EMG) findings. Therefore we searched out whether hand elevation test is related with EMG severity. Materials and Methods: We made a retrospective study of 654 bilateral carpal tunnel syndrome patients. Among them 134 were studied which had different hand elevation test results on each hands. The paired samples t-test was used to compare the EMG severity of each group. The relationships between hand elevation test and EMG severity were examined using Pearson-product correlations. Comparing whether the frequency of false negative hand elevation were different between both hands, and whether the severity of EMG depends on which side of hand is, was evaluated with Mann-Whitney U-test. Results: Severity of EMG in positive group was moderate to severe on average, whereas mild to moderate on negative group, with significant difference statistically (p<0.001). Correlation between the hand elevation test results and EMG severity also showed significance statistically (p<0.001). Conclusion: Mild severity of EMG was found out to be the factor affecting the false results. However, EMG severity and hand elevation test shows a meaningful correlation, supporting the value of hand elevation test.

• Physical Therapy Korea
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• v.16 no.3
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• pp.24-31
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• 2009

This study aimed to investigate the effect of differing heel heights on the electromyographic (EMG) activity in vastus medialis (VM) and vastus lateralis (VL) during stair ascending and descending activities. A total of 26 healthy women volunteered to perform stair-ascending and stair-descending tasks with 3 heel heights: barefoot, 3 cm, and 7 cm. The EMG activities of the VM and VL were recorded during the tasks. During the stair ascending and descending tasks, the EMG activities of both VM and VL significantly changed with differing the heel heights (p<.05). Moreover, the EMG activities of VM and VL during the stair ascending task were significantly higher than the corresponding values during the stair-descending task (p<.05). However, there were no significant differences between the VM:VL EMG ratios for the 3 heel heights (p>.05). The VM:VL EMG ratios between the 2 tasks differed significantly in the 7 cm high heel condition (p<.05). Despite an increase in the EMG activities in both VM and VL during stair ascending and descending tasks, there was no change in the relative EMG intensities of VM and VL, which was measured by calculating the VM:VL ratio this result indicates that no VM:VL imbalances were elicited. The relative EMG intensities of VM and VL during stair descent were lower than the corresponding values during the ascent, suggesting that VM and VL may show an imbalance in the eccentric activation during the weight-acceptance phase. This study provides useful information that will facilitate future research on how heel height affects muscle activity around the knee joint.

• Physical Therapy Rehabilitation Science
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• v.8 no.1
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• pp.1-7
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• 2019

Objective: The aim of this study was to evaluate the validity and reliability of using static surface electromyography (sEMG) on persons with neck pain and in healthy adults. Design: Cross-sectional study. Methods: Twenty-two female participants with neck pain and thirty healthy adults in the age group of 20-65 years were recruited in this study. To evaluate the validity and reliability of sEMG in subjects with neck pain, the subjects'characteristics were recorded and the Visual Analog Scale (VAS) and Neck Disability Index (NDI) were examined in addition to sEMG and algometer tests being carried out on the subjects. The site for using the sEMG and algometer was the upper trapezius. sEMG test-retest reliability was measured by intraclass correlation coefficients (ICCs). Independent t-tests were used to analyze the differences in the dependent variables between subjects with neck pain and healthy adults. The Pearson correlation coefficient was used to examine the linear relationship between measured variables. Results: sEMG and algometer tests were reliable according to the test-retest reliability results in subjects with neck pain and healthy adults (ICC=0.815-0.979). The results of this study showed that there were significant differences in respect to age, VAS, sEMG and algometer tests between persons with neck pain and healthy adults (p<0.05). The VAS and NDI were statistically correlated with sEMG and algometer results (p<0.05). Conclusions: In this study, we investigated the clinical usefulness of the static sEMG test in evaluating the pain scale of persons with neck pain with high reliability and validity.

• Journal of Biomedical Engineering Research
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• v.44 no.5
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• pp.336-345
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• 2023

The present study was designed to evaluate changes in neuromuscular properties and the structural and qualitative characteristics of muscles during submaximal isometric contractions at low-to-relatively vigorous target forces and to determine their influence on force steadiness (FS). Thirteen young adult males performed submaximal isometric knee extensions at 10, 20, 50, and 70% of their maximal voluntary isometric contraction using their non-dominant legs. During submaximal contractions, we recorded force, EMG signals from vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF), and ultrasound images from the distal RF (dRF). Force and EMG standard deviation (SD) and coefficient of variation (CV) values were used to measure FS and EMG steadiness, respectively. Muscle thickness (MT), pennation angle (PA), echo intensity (EI), and texture features were calculated from ultrasound images to assess the structural and qualitative characteristics of the muscle. FS, neuromuscular properties, and texture features showed significant differences across different force levels. Additionally, there were significant differences in EMG_CV among the quadriceps at the 50% and 70% force levels. The results of correlation analysis revealed that FS had a significant relationship with EMG_CV in VM, VL, and RF, as well as with the texture features of dRF. This study's findings demonstrate that EMG steadiness and texture features are influenced by the magnitude of the target force and are closely related to FS, indicating their potential contribution to force output control.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.271-284
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• 2004

The purpose of this study was to analyse the EMG activity of selected muscles with balance taping treatment and blood fatigue makers which accumulated during exercise of progressive maximal intensity. Ten male college students who did not experience any cardiovascular and musculo-skeletal disease were participated in this study. Balance taping were applied to rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinous, semimembranous, and around knee joint. Isokinetic knee joint flexion/extension force, EMG activity, lactate and ammonia as blood fatigue makers during progressive maximal intensity exercise were measured for with/without applying balance taping. The results indicated that although flexion force of total work at $60^{\circ}/sec$ with taping was increased applied taping did not affect to the aerobic exercise ability parameters. Lactate level as blood fatigue makers during progressive maximal intensity exercise after taping was decreased but the ammonia level did not change with same treatment. In isokinetic knee joint test at the angular velocity of $60^{\circ}/sec$, $180^{\circ}/sec$, and $240^{\circ}/sec$ the taping treatment did not affect to any selected muscle EMG activities except maximal EMG of vastus lateralis at $240^{\circ}/sec$.

• Journal of Engineering Education Research
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• v.19 no.1
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• pp.31-36
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• 2016

These days, ICT-related products are pouring out due to development of mobile technology and increase of smart phones. Among the ICT-related products, wearable devices are being spotlighted with the advent of hyper-connected society. In this paper, a body-attached type wearable device using EMG(electromyography) sensors is studied. The research field of EMG sensors is divided into two parts. One is medical area and another is control device area. This study corresponds to the latter that is a method of transmitting user's manipulation intention to robots, games or computers through the measurement of EMG. We used commercial device MYO developed by Thalmic Labs in Canada and matched up EMG of arm muscles with gesture controller. In the experiment part, first of all, various arm motions for controlling devices are defined. Finally, we drew several distinguishing kinds of motions through analysis of the EMG signals and substituted a joystick with the motions.

• The Journal of Korean Physical Therapy
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• v.25 no.6
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• pp.411-416
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• 2013

Purpose: The purpose of the present study was to determine the effects of activation of gluteus maximus (Gmax) and abdominal muscle using EMG biofeedback on lumbosacral and tibiocalcaneal angles in standing position. Methods: Fourteen healthy subjects with normal feet participated in the present study. Electromyographic (EMG) biofeedback using visual cue was used to activate the external oblique (EO) and Gmax. The lumbosacral and tibiocalcalcaneal angles were measured by electronic goniometers. All the subjects were instructed to activate the Gmax and EO monitoring increasing amounts of the muscle activities in each muscle. The lumbosacral and tibiocalcaneal angles were collected in three trials during resting and activation of each muscle using EMG biofeedback in standing position. The mean value of three trials was used in the data analysis. A paired-t test was used to compare the lumbosacral and tibiocalcaneal angles between resting and activation of the Gmax and EO using EMG biofeedback. Results: The lumbosacral and tibiocalcaneal angles were significantly less in the resting compared to activation using EMG biofeedback (p<0.05). Conclusion: The activaition of Gmax and abdominal muscles using EMG biofeedback play role to control the pronation of subtalar joint during the weight-bearing.

• Journal of the Ergonomics Society of Korea
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• v.19 no.2
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• pp.87-99
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• 2000

This study aims to examine a fuzzy logic-based human expert EMG prediction model (FLHEPM) for predicting electromyographic responses of trunk muscles due to manual lifting based on two task (control) variables. The FLHEPM utilizes two variables as inputs and ten muscle activities as outputs. As the results, the lifting task variables could be represented with the fuzzy membership functions. This provides flexibility to combine different scales of model variables in order to design the EMG prediction system. In model development, it was possible to generate the initial fuzzy rules using the neural network, but not all the rules were appropriate (87% correct ratio). With regard to the model precision, the EMG signals could be predicted with reasonable accuracy that the model shows mean absolute error of 8.43% ranging from 4.97% to 13.16% and mean absolute difference of 6.4% ranging from 2.88% to 11.59%. However, the model prediction accuracy is limited by use of only two task variables which were available for this study (out of five proposed task variables). Ultimately, the neuro-fuzzy approach utilizing all five variables to predict either the EMG activities or the spinal loading due to dynamic lifting tasks should be developed.