• Journal of Korean Medicine Rehabilitation
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• v.28 no.1
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• pp.85-96
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• 2018

Objectives This study was performed to compare the electrical methods of motor points mapping using surface EMG and electric probe (Pointer Excel II). Methods 32 healthy adults (male 16, female 16) were selected. and classified into two groups; surface EMG group, electric probe (Pointer Excel II) group. In surface EMG group, motor points were searched by recoding the compound muscle potentials. In electric probe (Pointer Excel II) group, motor points were searched by scanning the skin with Pointer Excel II at low level stimulation. The locations of the motor points were expressed as X and Y values in relation to the reference line. The horizontal reference line was set as elbow crease and the vertical reference line was set as the line connecting coracoid process to the center of the horizontal reference line. The data was analyzed by 'Independent T-test' and 'equivalence test'. Results 1. The motor points of short head and long head of biceps brachii muscle were located at about 2/3 length of the vertical reference line from coracoid process and about 1/5~1/4 length of the half of the horizontal reference line from the vertical reference line in both group. 2. The motor points of the short head were located more distally and close to the vertical reference line (p<0.001). 3. In surface EMG group, the motor points of the long head were located more laterally in the female than male. And the motor points of the long head were located more distally in the left side than right side (p<0.05). In electric probe (Pointer Excel II) group, similar tendency was observed but there was no statistically significant difference (p>0.05). 4. As a result of the equivalence test between surface EMG group and electric probe (Pointer Excel II) group, the confidence intervals of the difference were within the equivalence limit. Therefore, the locations of the motor points searched by two ways are equa l (p>0.05, equivalence interval=3%). Conclusions The results indicate that electric probe (Pointer Excel II) can be used to search the motor points instead of surface EMG. This might improve the clinical efficiency when using the motor points to treat muscle dysfunction.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.9-19
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• 2022

In this study, a systematic review was conducted to analyze the method of applying sEMG to evaluate the swallowing function of the elderly at each stage of swallowing, and to help objectively measure the swallowing stage of the older adults in clinical practice. From 2011 to 2021, 7 studies that met the selection criteria were selected using Pubmed, Scopus, and Web of Science (WoS). As a result of this study, the older adults and adults were divided into an experimental group and a control group and the swallowing phase was analyzed using sEMG only for the older adults. sEMG was used to evaluate swallowing in the oral and pharyngeal stages, and the sEMG attachment site was attached to the swallowing muscle involved in each stage. The collected sEMG data were filtered using a bandpass-filter and a notch-filter, and were analyzed using RMS, amplitude, and maximum spontaneous contraction. In this study, it was found that sEMG can be used as a tool to objectively and quantitatively evaluate the swallowing function in stages. Therefore, it is expected that this study will activate various studies that incorporate sEMG to evaluate the swallowing function in stages.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.189-196
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• 2020

We have developed a device for recording biological data by inserting three electrodes and a needle with an angular velocity sensor into the moth for the purpose of measuring the electromyogram of the flapping and the corresponding lift force. With this measurement, it is possible to evaluate the moth-physiological function of moths, and the amount of pesticides that insects are exposed to (currently LD50-based standards), especially the amount of chronic low-concentration exposure, can be reduced the dose. We measured and recorded 2-channel electromyography (EMG) and angular velocity corresponding to pitch angle (pitch-like angle) associated with wing flapping for 100 sweet potato hawkmoths (50 females and 50 males) with the animals suspended and constrained in air. Overall, the angular velocity and amplitude of EMG signals demonstrated high correlation, with a correlation coefficient of R = 0.792. In contrast, the results of analysis performed on the peak-to-peak (PP) EMG intervals, which correspond to the RR intervals of ECG signals, indicated a correlation between ΔF fluctuation and angular velocity of R = 0.379. Thus, the accuracy of the regression curve was relatively poor. Using a DC amplification circuit without capacitive coupling as the EMG amplification circuit, we confirmed that the baseline changes at the gear change point of wing flapping. The following formula gives the lift provided by the wing: angular velocity × thoracic weight - air resistance - (eddy resistance due to turbulence). In future studies, we plan to attach a micro radio transmitter to the moths to gather data on potential energy, kinetic energy, and displacement during free flight for analysis. Such physiological functional evaluations of moths may alleviate damage to insect health due to repeated exposure to multiple agrochemicals and may lead to significant changes in the toxicity standards, which are currently based on LD50 values.

• The Journal of Korean Physical Therapy
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• v.32 no.3
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• pp.157-162
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• 2020

Purpose: This study was to evaluate several tasks performed at a high intensity in terms of their ability to elicit EMG activity in the serratus anterior by comparing the EMG activities of the serratus anterior, upper trapezius, and lower trapezius muscles during six tasks combined shoulder flexion with rotation. Methods: Fifteen healthy males were recruited to this study. Each subject was instructed to assume a sitting position without back support and asked to flex (90° or 120°) the right shoulder and protract the scapula in the sagittal plane with maximal external rotation; to assume a neutral position; or to internally rotate the glenohumeral joint. The EMG data were collected from the serratus anterior (SA), upper trapezius (UT), and lower trapezius (LT) muscles were normalized to maximum voluntary isometric contraction. The UT/LT and UT/SA muscle activity ratios in each task were assessed by calculating the surface EMG. Data were analyzed by two-way repeated-measures analysis of variance, with the level of significance set at p<0.05. Results: The results of this study, shoulder flexion with external rotation resulted in low upper trapezius/serratus anterior and upper trapezius/lower trapezius ratios and a relatively high level of serratus anterior activation. Conclusion: Shoulder flexion with external rotation used herein may be considered as important for clinical interventions aimed at selectively increasing SA strengthen and clinical selection of exercises for improving glenohumeral joint and scapulothoracic control.

• Physical Therapy Korea
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• v.8 no.3
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• pp.11-26
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• 2001

In rehabilitation programs involving muscle re-education and endurance exercise, it is necessary to confirm when fatigue occurs. It is also necessary to quantify fatigue, to confirm whether the muscle has been exercised sufficiently. In general, as fatigue occurs, the force-generating ability of the muscle is reduced. If the median frequency (MDF) obtained from electromyogram (EMG) power spectrum is correlated highly with work, then the timing and degree of fatigue may be confirmed. This study examined the relationship between work and MDF obtained from the EMG power spectrum during repetitive isokinetic exercise. Surface EMG signals were collected from biceps brachii and vastus lateralis of 52 normal subjects (26 males, 26 females) at $120^{\circ}/sec$ and $60^{\circ}/sec$ while performing an isokinetic exercise. The exercise was finished at 25% of peak work. MDF data was obtained using a moving fast Fourier transformation (FFT), and random noise was removed using the inverse FFT, then a new MDF data was obtained from the main signal. There was a high correlation between work and MDF during repetitiv isokinetic exercise in the biceps brachii and vastus lateralis of males and the biceps brachii of females (r=.50~.77). However, there was a low correlation between work and MDF in the vastus lateralis of females (r=.06~.19).

• Physical Therapy Korea
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• v.25 no.3
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• pp.1-11
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• 2018

Background: Lumbopelvic stability is highly important for exercise therapy for patients with low back pain and shoulder dysfunction. It can be attained using a pelvic compression belt. Previous studies showed that external pelvic compression (EPC) enhances form closure by reducing sacroiliac joint laxity and selectively strengthens force closure and motor control by reducing the compensatory activity of the stabilizer. In addition, when the pelvic compression belt was placed directly on the anterior superior iliac spine, the laxity of the sacroiliac cephalic joint could be significantly reduced. Objects: This study aimed to compare the effects of EPC on lumbopelvic and shoulder muscle surface electromyography (EMG) activities during push-up plus (PUP) and deadlift (DL) exercise, trunk extensor strength during DL exercise. Methods: Thirty-eight subjects (21 men and 17 women) volunteered to participate in this study. The subjects were instructed to perform PUP and DL with and without the EPC. EMG data were collect from serratus anterior (SA), pectoralis major (PM), erector spinae (ES), and multifidus (MF). Trunk extensor strength were tested in DL exercise. The data were collected during 3 repetitions of all exercise and the mean of root mean square was used for analysis. Results: The EMG activities of the SA and PM were significantly increased in PUP with pelvic compression as compared with PUP without pelvic compression (p<.05). In DL exercise, a significant improvement in trunk extensor strength was observed during DL exercise with pelvic compression (p<.05). Conclusion: The results of this study indicate that lumbopelvic stabilization reinforced with external pelvic compression may be propitious to strengthen PUP in more-active SA and PM muscles. Applying EPC can improve the trunk extensor strength during DL exercise. Our study shows that EPC was beneficial to improve the PUP and DL exercise efficiency.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.16 no.1
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• pp.9-19
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• 2010

Purpose : To identify whether isometric shoulder horizontal extension (ISHE) exercise could sufficiently activate the lumbar multifidus muscle, and to determine appropriate exercise intensity to increase muscle strength. Methods : Twenty healthy volunteers (10 males and 10 females) participated in this study. ISHE exercises on the dominant side were performed with $90^{\circ}$ shoulder abduction held in $90^{\circ}$ elbow flexion so that their arms were in the horizontal plane. Electromyographic (EMG) measurements of multifidus activation were performed in standing and supine positions, and were taken under four strength conditions: 75%, 50% and 25% of maximum shoulder horizontal extension strength, and maximum strength. Results : The EMG activations of both lumbar multifidus increased significantly with ISHE exercises of larger % strength (p<.05). In their multifidus EMG data measured in standing and supine positions, men differed significantly in their 75%, 50% and 25% strength for both sides (p<.05), and women differed significantly in their 75%, 50% and 25% strength on their 5th lumbar vertebrae's left side, but 75% only for their 5th lumbar vertebrae's right side (p<.05). The EMG data of 5th lumbar vertebrae's left and 5th lumbar vertebrae's right sides appeared to differ significantly at all strength levels for men while standing, but only at the 25% level for women in the supine position (p<.05). These findings indicate that ISHE exercises can be considered a beneficial method to enhance the multifidus strength. Conclusion : This study provides useful information for further study in this field.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.143-150
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• 2016

In this paper, we propose Korean monophthong recognition method optimizing muscle mixing based on facial surface EMG signals. We observed that EMG signal patterns and muscle activity may vary according to Korean monophthong pronunciation. We use RMS, VAR, MMAV1, MMAV2 which were shown high recognition accuracy in previous study and Cepstral Coefficients as feature extraction algorithm. And we classify Korean monophthong by QDA(Quadratic Discriminant Analysis) and HMM(Hidden Markov Model). Muscle mixing optimized using input data in training phase, optimized result is applied in recognition phase. Then New data are input, finally Korean monophthong are recognized. Experimental results show that the average recognition accuracy is 85.7% in QDA, 75.1% in HMM.

• PNF and Movement
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• v.12 no.1
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• pp.19-25
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• 2014

Purpose: To investigate the effect of action observation training on the muscle onset time and symmetrical use of rectus femoris(RF) and gastrocnemius medialis(GCM) during sit-to-stand (STS). Methods: Sixteen patients with stroke entered a single-blind trial and were randomly assigned to the experimental(Action) or control(Landscape) groups. Those in the Action observation group watched video clips showing specific movement and strategies to STS, wheas those in the control group watched video clips of static pictures showing differnet landscapes. All patients was measured the EMG data in the STS on the affected side and unaffected side. The EMG data were collected from RF and GCM while performing the STS task. The EMG onset time and onset time ratio for the RF and GCM were calculated by dividing the EMG onset time of RF and GCM action on the affected side by these on the unaffected side. Results: Onset time of affected side RF, GCM was significantly faster action observation training group than control group(p<.05). But interventions before and after the symmetry did not show a significant increase. Conclusion: There findings suggest that action observation training has a positive effect on the muscle onset time shortened during STS tasks.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.479-487
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• 2004

Biopotential signals have been used as command in systems using electrical stimulation of motor nerves to restore movement after an injury to the central nervous system (CNS). In order to use the voluntary EMG (electromyography) among the biopotentials as a control signal for the electrical stimulation of the same muscle for CNS injury patients, it is necessary to remove M-wave of having high magnitude from raw data. We designed an optimal filter for removing the M-wave and preserving the voluntary EMG and showed that the optimal filter is eigen filter. We also proved that the previous method using the prediction error filter(PEF) is a suboptimal filtering in the sense of preserving the voluntary EMG. On basis of the data obtained from a model for M-wave and voluntary EMG and from actual CNS injury patients, with false-positive rate analysis, the proposed adaptive filter showed a very promising performance in comparison with previous method.