• 한국전문물리치료학회지
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• 제10권1호
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• pp.109-128
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• 2003

This study tested whether repeated measurement of median frequency (MDF)-related variables could express the muscle power changes during a 12-week DeLome strengthening program, by using consecutive overlapping FFT (Fast Fourier transformation) and integrated EMG (IEMG) from surface EMG data for isometric and isotonic exercise. To evaluate the effect of training, the following were recorded every 3 weeks for the elbow flexors and knee extensors of 5 healthy male volunteers: MVC, lRM, limb circumference, and surface EMG during isometric MVC or isotonic contraction at 10RM load. From the EMG data, IEMG and variables from a regression analysis between MDF and time were obtained. MVC, lRM, IEMG, and initial MDF increased linearly over the training period. The fatigue index and slope of the regression line increased temporarily until the 6th week and decreased thereafter. From these results, there appeared to be enhanced neural recruitment of fast twitch fibers in the first 6 weeks and continued enhancement in the recruitment and hypertrophy of fast twitch fibers, which led to increased fatigue resistance, over the last 6 weeks. Accordingly, the MDF and IEMG analysis technique could demonstrate the effect of the program detected significant changes in both isometric and isotonic contractions. EMG analysis methods can be used to estimate the electrophysiological and histological changes in skeletal muscles during a strengthening program.

• Transactions on Electrical and Electronic Materials
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• 제18권5호
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• pp.298-302
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• 2017

With an increasing aging population and improved standards of living, more attention has been paid to health. Although walking exercise is known as an aerobic exercise, it imposes repeated and continuous impacts on the joints of the lower extremities. Therefore, when overweight gives a burden to the lower extremity or there is a joint disease, exercise limit occurs. The articular cartilage, weakened with age, also makes it difficult for the elderly to perform walking exercises. Accordingly, this study conducted a comparative analysis between regular walking using only the lower extremity and Nordic walking, which has been known as stable. For analysis, electromyography (EMG) was performed and the ground reaction force of the upper and lower extremities were measured in the same exercise. Integrated EMG (iEMG) revealed that the upper extremity muscles were more active in Nordic walking than in regular walking, where lower extremity muscles were relatively more inactive. In addition, when EMG measurements were performed at each measurement point during walking exercise, the pattern was different. Nevertheless, the result was the same as in iEMG. The load that occurs in each exercise was measured using the ground reaction force system. As a result, Nordic walking had a lower load than regular walking. Therefore, it was found that Nordic walking minimized the load on the lower extremities owing to the effect of whole-body exercise and was a safer and more efficient exercise method.

• The Journal of Korean Physical Therapy
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• 제25권1호
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• pp.16-22
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• 2013

Purpose: This study evaluated the validity of measuring paravertebral muscle function with 3D-NEWTON (Hanmed, Korea) by assessing the correlation between Biodex (Biodex, USA) and surface electromyography (EMG). Methods: Nineteen healthy adults participated. The function of their paravertebral muscle was measured in three ways. Maximum endurance time was measured in seconds when 3D-NEWTON was inclined forward for assessing extensor function, and inclined backward for assessing flexor function. Using surface EMG, maximum muscle activity was obtained from the eractor spinae and rectus abdominis during the 3D-NEWTON measurement. Maximum muscle activity was the mean activity from 10 seconds when the root mean squared firing data was highest. Through Biodex the peak torques of the extensor and flexor were measured during isometric exercises. The Spearman correlation coefficiencts from 3D-NEWTON, surface EMG, and Biodex were calculated. Results: The data from surface EMG and Biodex were statistically correlated when measured for flexor function, but less so for extensor function. In the case of 3D-NEWTON, the correlation coefficient with Biodex was 0.50 (p=0.05), while the coefficient with surface EMG was 0.53 (p=0.02) when measured for extensor function. Similarly, the correlation coefficienct with Biodex was 0.60 (p=0.01), while the surface EMG was 0.51 (p=0.03) for flexor function. Conclusion: 3D-NEWTON was a useful method for measuring paravertebral muscle function and can give helpful information for treating people with diseases associated with the lumbar spine.

• 대한인간공학회지
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• 제26권2호
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• pp.157-165
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• 2007

The Work-Related Musculoskeletal Disorders (WMSDs) can be occurred by various factors such as repetition, forceful exertions and awkward postures. Especially, occurrences of the WMSDs on the waist and lower limb are reported in workplaces, demanded standing postures for a long time, in service and manufacturing industry. The static and standing postures without movement for a long time increase work loads to the lower limb and the waist. Accordingly, anti-fatigue mat or anti-fatigue insole is used as a preventing device of the WMSDs. However anti-fatigue mats are limited in space and movement. In this study, multi-elastic insoles are designed and shown the effects of the workload reduction for a long time under the standing work. The foot pressures and EMG (Electromyography) are measured at 0 hour and after 2 hours by 6 health students in their twenties. The 6 prototype insoles are designed with three elastic (Low, Medium and High). These insoles are compared with no insole (insole type 7) as control group. The EMG measurement was conducted to waist (erector spinae muscle), thigh (vastus lateralis muscle) and calf (gastrocnemius muscle). The foot pressure is analyzed by mean pressure value and the EMG analysis is investigated through MF (Median Frequency), MPF (Mean Power Frequency) and ZCR (Zero Crossing Rate). The results of the foot pressure show that the multi-elastic insoles had smaller foot pressure value than that of no-insole. Moreover, Insole 2 and Insole 3 have the smallest increasing rate in foot pressure. The EMG results show that the multi-elastic insoles had smaller EMG shift value than that of no-insole in 2 hour, and then shift value shows the smallest value in Insole 2. Therefore, this study presents that the multi-elastic insoles have reducing effects of the work load for a long time standing work in both side of foot pressure and EMG.

• 대한의용생체공학회:의공학회지
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• 제40권6호
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• pp.223-229
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• 2019

The number of knee-related disease patients and knee joint surgeries is steadily increasing every year, and for knee rehabilitation training for these knee joint patients, it is necessary to strengthen the muscle of vastus medialis and quadriceps femoris. However, because of the cost and time-consuming difficulties of receiving regular hospital treatment in the course of knee rehabilitation, we developed knee exoskeleton using rapid prototype for knee rehabilitation with feedback from the electromyogram (EMG) and inertia motion unit (IMU) sensor. The modules was built on the basis of EMG and an IMU sensor applied complementary filter, measuring muscle activity in the vastus medialis and the range of joint operation of the knee, and then performing the game based on this measurement. The IMU sensor performed up to 97.2% accuracy in experiments with ten subjects. The functional game contents consisted of an exergaming platform based on EMG and IMU for the real-time monitoring and performance assessment of personalized isometric and isotonic exercises. This study combined EMG and IMU-based functional game with knee rehabilitation training to enable voluntary rehabilitation training by providing immediate feedback to patients through biometric information, thereby enhancing muscle strength efficiency of rehabilitation.

• 한국의류산업학회지
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• 제25권2호
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• pp.210-220
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• 2023

Recently, smart wearable products, including electromyography (EMG) measurement devices and clothing, have been developed to monitor users' exercise levels, muscle activation, and muscle balance more effectively during fitness activities. However, technical and socioeconomic barriers, such as flexibility and durability, still pose challenges in terms of comfort, ease of wear, and wearability of smart clothing, which includes devices and circuits. To address these issues, this study developed a wearable EMG device integrated with clothing to collect valid EMG signals from desired muscles while maintaining comfort, functionality, and ease of wear. After deriving a combined structure that could stably position the wearable device within the clothing, a prototype was manufactured and evaluated for fit, compression, comfort, and exercise comfort test by ten participants (height = 176.2 cm, weight = 76.4 kg, chest circumference = 101.2 cm). The study found that the prototype had smaller circumferences around the chest, waist, and abdomen compared to commercial products, resulting in lower ratings for wearing comfort and ease of wear. However, the prototype received high ratings for fitting, pressure, and the exercise comfort test. Valid signals were obtained when the EMG device was combined to the prototype for the rectus femoris muscle, indicating stable positioning of the device during exercise.

• 한국운동역학회지
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• 제16권1호
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• pp.31-41
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• 2006

The primary purpose of a TKA is to restore normal knee function Therefore, ideally, a TKA should: (a) maintain the natural leverage of the knee joint muscles to ensure generating adequate knee muscle moments to accomplish daily tasks such as rising from climbing stairs; (b) provide adequate knee joint stability. A 16-channel MyoResearch XP EMG system was used to collect the differential input surface electromyography signals VM, VL, RF, BF, ST during climbing/descending stair tests. A Peak Motion Measurement System was used to collect the kinematic and kinetic data. AKIN-COM Ill isokinetic dynamometer was used for EMG of VM, VL, RF, BF and ST during maximal voluntary contraction. I Quadriceps EMG results for the VM of the passed 1year group limb demonstrated significant less RMS EMG than that of the passed 3year group limb $60^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The VL of the passed 1year group limb also demonstrated significants less RMS EMG than that of the passed 3year group limb from $60^{\circ}-45^{\circ}$ of knee flexion(p<0.05). Similar to the VM and VL, the RF of the passed 1year group limb showed less RMS EMG than that of the passed 3year group limb from $60^{\circ}-30^{\circ}$ do knee flexion(p<0.05). Hamstring EMG results for the BF of the passed 1year group limb demonstrated less RMS EMG than that of the passed 3year group limb from $75^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The passed 1year group limb tended to have less ADD displacement(p<0.071) than that of the passed 3year group limb. There was no significant difference of the ABD displacement between the passed 1year group and the passed 3year group limbs(p<0.73). The passed 3year group used compensatory adaptation movement strategies to compensate for the strength deficit of passed 3year group limbs. The passed 3year group limb also increased the quadriceps muscle activation level to produce more knee extension moment to compensate for the short quadriceps moment arm. The passe 3year group limb might have an unstable knee joint in the medio-Iateral direction during the climbing/descending by showing a tendency of more ADD displacement and greater hamming co-activation EMG than the passed 1year group limbs. The TKA design was not able to help the knee joint to produce adequate knee extension moment with less quadriceps muscle effort. I think that old man needs continuous exercise for muscle strength.

• Journal of Acupuncture Research
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• 제34권2호
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• pp.75-82
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• 2017

Objectives : The purpose of this study was to determine the electrical properties of the buccal area using facial surface electromyography (sEMG). Methods : This research was conducted on 44 healthy participants irrespective of their sex. Surface electrodes were attached to the midpoints of three imaginary lines connecting ST4 (Dicang) to ST6 (Jiache), ST4 to SI18 (Quanliao), and ST4 to the center point of SI18 and ST6. Then, the participants were trained in the movement that included a comprehensive action of buccal area. While the participants were performing the motion, sEMG values ($E_1$, $E_2$, $E_3$) and the distance change of the three imaginary lines ($D_1$, $D_2$, $D_3$) were measured. The data were statistically analyzed using SPSS ver. 22.0. Results : Significant differences were observed in the distance changes ($D_1$>$D_3$, $D_2$>$D_3$) and sEMG values ($E_1$<$E_2$<$E_3$). Moreover, there were positive correlations between $D_1$ and $E_1$, $D_2$ and $E_2$. Conclusion : We suggest that the measurement at ST4 to the center point of ST6 and SI18 with this motion would be adequate to check the electrical characteristics of the buccal area.

• 감성과학
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• 제26권4호
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• pp.41-50
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• 2023

본 연구는 EMG(electromyography) 텍스타일 전극 개발을 목적으로 레이어 수의 디자인 및 원단을 다르게 하여 성능 및 신호 획득 안정성을 평가한다. 레이징 및 프레스 공정을 통하여 텍스타일 전극을 제조하며 Layer-0, Layer-1, Layer-2로 레이어 유무 및 수에 따른 결과를 분석했다. 이에 레이어 유무에 따라서는 근활성 측정에 영향을, 수가 많을수록 높은 성능이 나타남을 확인할 수 있었다. Layer-2 구조로 통일하여 5가지의 원단(네오프렌, 스판덱스 쿠션, 폴리에스테르 100%, 나일론 스판덱스, 광목 캔버스)으로 전극을 제조해 실험해 보았다. 성능적인 면에서, 원단의 중량이 높은 나일론 스판덱스가 높은 성능을 보였으며, 스판쿠션 텍스타일 전극이 근활성도 수득에 높은 안정성을 보였다. 이에 위 연구는 레이어에 따른 성능 연관성과 전극-피부사이의 닿는 면적 간의 관계 등을 고찰하여 슬리브 전체의 의복압을 늘리는 대신 특정 센서 측정 부위에만 높은 압력을 가함으로 차후 연구에서 레이어의 수 및 물성에 따른 전극의 공학적 설계 가능성을 제시한 의의가 있다.

• Journal of Acupuncture Research
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• 제31권2호
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• pp.51-63
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• 2014

Background or Objectives : The purpose of this study is to measure surface Electromyography(sEMG) of facial muscles in normal person and to find method for standardizing of sEMG's value. Methods : We measured 3points on face, frontalis muscle($GB_{14}$), zygomaticus muscle($SI_{18}$), orbicularis oris muscle($LI_{19}$) of 40 normal person by sEMG. 40 normal person consist with two groups, each 20 male, 20 female. Average age of subject was $26.50{\pm}4.79$. SEMG instrument QEMG-4 XL was used. After training exercise of facial muscles, sEMG's root mean square value was measured once. Results : 1. In whole experimental group, frontalis muscle's both side average was $78.36{\pm}40.87$, zygomaticus muscle's both side average was $84.70{\pm}49.81$, orbicularis oris's both side average was $104.83{\pm}38.81$. 2. Left side of Frontalis muscle, both side of zygomaticus muscle are high marked in male than female in statistically. 3. In whole experimental group, average of ratio comparing smaller value with bigger value in difference between left side and right side was $19.60{\pm}12.88$ %. 4. Average of asymmetry index(AI) was $11.46{\pm}8.36$ %. orbicularis oris muscle's average of AI had least difference was $8.95{\pm}7.50$ %. zygomaticus muscle's average of AI had most difference was $13.95{\pm}8.90$ %. Conclusions : The result of this study could provide useful information of field of sEMG is used in oriental medicine treatment of facial muscles. To assess efficacy of treatment in facial muscles, we need to standardize facial muscle's sEMG values by using AI, ratio comparing values and etc.