• Journal of Korea Multimedia Society
• /
• v.24 no.8
• /
• pp.1035-1043
• /
• 2021

The shoulder is less stable than other joints, making it easier to onset of various shoulder disorders. In addition, limited range of motion and pain in the shoulder due to shoulder disorders restricts daily life and social activities. The problem with exercise therapy can be reduced in exercise effect by causing boredom through simple repetition of motion, thus reducing the patient's willingness to participate. Therefore, this paper aims to provide a treatment method that can induce active participation of patients by developing devices capable of passive, active, and resistance exercise and serious game contents using them. Furthermore, sEMG was used to verify whether the rotational exercise in the horizontal and vertical using serious game contents helps the shoulder movement actually. The measured sEMG signal was classified as 5 phases according to the angle of rotation and calculated the mean integrated EMG. The mean integrated EMG for the experimental results was higher in all phases when rotational was performed compared to those when both horizontal and vertical rotational exercise remained initial posture, indicating an increase in muscle activity.

• The Journal of Korean Academy of Prosthodontics
• /
• v.25 no.1
• /
• pp.213-226
• /
• 1987

The purpose of this study was to standardize and classify the coordination pattern among the left and right masseter and anterior temporal muscles, in terms of integrated EMG values per stroke during gum chewing in normal subjects. In this study, 20 normal subjects were selected to chew a piece of gum and integrated EMG from middle portion of the masseter and anterior temporal muscles on both sides were recorded 20 times during each of the right and left chewing respectively. And the Bioelectric Processor Model EM2 (Myo-tronies Research, Inc., U.S.A.) with the surface electrodes was used to record the EMG activity during all experimental procedures. The results were as follows; 1. In all subjects, the chewing side masseter muscle was predominantly active among the four muscles examined. 2. The integrated EMG value of the middle of masseter muscle was significantly predominant than those of the anterior temporal muscle (p<0.0001) on the chewing side, but no significant predominant was observed on the nonchewing side (p<0.98). 3. In comparison with same muscles on the chewing and nonchewing side, low correlation coefficient was found between the middle of masseter muscles (R=0.317), but high correlation coefficient was found between the anterior temporal muscles (R=0.738). Between two muscles on the same side, there were significant correlation in the chewing (R=0.557) and nonchewing side (R=0.625). 4. In the coordination patterns among four muscles examined, distinct individual differences were found, but in an identical subject one fixed pattern appeared with significant reproducibility.

• Journal of Internet Computing and Services
• /
• v.25 no.2
• /
• pp.57-67
• /
• 2024

This paper explores the potential of electromyography (EMG) as a means of gesture recognition for user input in gesture-based interaction. EMG utilizes small electrodes within muscles to detect and interpret user movements, presenting a viable input method. To classify user gestures based on EMG data, machine learning techniques are employed, necessitating the preprocessing of raw EMG data to extract relevant features. EMG characteristics can be expressed through formulas such as Integrated EMG (IEMG), Mean Absolute Value (MAV), Simple Square Integral (SSI), Variance (VAR), and Root Mean Square (RMS). Additionally, determining the suitable time for gesture classification is crucial, considering the perceptual, cognitive, and response times required for user input. To address this, segment sizes ranging from a minimum of 100ms to a maximum of 1,000ms are varied, and feature extraction is performed to identify the optimal segment size for gesture classification. Notably, data learning employs overlapped segmentation to reduce the interval between data points, thereby increasing the quantity of training data. Using this approach, the paper employs four machine learning models (KNN, SVC, RF, XGBoost) to train and evaluate the system, achieving accuracy rates exceeding 96% for all models in real-time gesture input scenarios with a maximum segment size of 200ms.

• Korean Journal of Applied Biomechanics
• /
• v.20 no.3
• /
• pp.277-284
• /
• 2010

The purpose of this study was to investigate the trunk rotation type by wheel and axle. In order to analysis, 3D-motion analysis and electromyography were conducted on kinematic variables, impulse, average-EMG and integrated-EMG. Twelve healthy (age: $21.8{\pm}2.2$ yrs, height: $175.4{\pm}5.0cm$, weight: $66.7{\pm}6.4kg$) participated in the experiment. The results were as follows; in hand's velocity and acceleration, wheel and axial rotating movement using kinematic chain(type 3) were much faster. In impulse, type 3 was much stronger. In average-EMG, right and left, latissimus dorsi muscles was much stronger. In integrated-EMG, left erector spinae, right/left latissimus dorsi, and left external oblique muscles was much stronger. These results considered that, in the trunk rotation utilizing the kinematic chains action, latissimus dorsi muscles highly contribute to the muscle utilization that makes the rotating movement maximally effective.

• Korean Journal of Applied Biomechanics
• /
• v.23 no.2
• /
• pp.141-148
• /
• 2013

The purpose of this study was to investigate the scapulothoracic joint movement between different weight bearing contributing to effective bench press exercise. Ten male subjects participated in this study. All subjects were tested on the flat bench press machine which modified weight (50% and 70% of 1RM) and subjects were performed two different conditions(none protraction condition and protraction condition). Weight bar height and vertical velocity, EMG activation was measured using 3D motion capture system and wireless EMG analysis system. As the results, none protraction condition showed that it is more concentrate better pectoralis major muscle activation than protraction condition and middle pectoralis major, anterior deltoid and triceps brachii was significant higher integrated EMG in 70% of 1RM condition. In conclusion, limited scapulothoracic joint movement was more effective activated pectoralis major muscle all the weight through, while we could not find that it was not affected integrated EMG on eight muslces related to shoulder complex between scapulothracic joint movement conditions.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.20 no.1
• /
• pp.119-128
• /
• 2017

G-induced Loss of Consciousness(G-LOC) can be predicted by measuring Electromyogram(EMG) signals. Existing studies have mainly focused on specific body parts and lacked of consideration with quantitative EMG indices. The purpose of this study is to analyze the indices of EMG signals by human body parts for monitoring G-LOC condition. The data of seven EMG features such as Root Mean Square(RMS), Integrated Absolute Value(IAV), and Mean Absolute Value(MAV) for reflecting muscle contraction and Slope Sign Changes(SSC), Waveform Length (WL), Zero Crossing(ZC), and Median Frequency(MF) for representing muscle contraction and fatigue was retrieved from high G-training on a human centrifuge simulator. A total of 19 trainees out of 47 trainees of the Korean Air Force fell into G-LOC condition during the training in attaching EMG sensor to three body parts(neck, abdomen, calf). IAV, MAV, WL, and ZC under condition after G-LOC were decreased by 17 %, 17 %, 18 %, and 4 % comparing to those under condition before G-LOC respectively. Also, RMS, IAV, MAV, and WL in neck part under condition after G-LOC were higher than those under condition before G-LOC; while, those in abdomen and calf part lower. This study suggest that measurement of IAV and WL by attaching EMG sensor to calf part may be optimal for predicting G-LOC.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.53 no.2
• /
• pp.103-110
• /
• 2004

This paper proposes a new method on the EMG AR(autoregressive) modeling in pattern recognition for various head motions. The proper electrode placement in applying AR or cepstral coefficients for EMG signature discrimination is investigated. EMG signals are measured for different 10 motions with two electrode arrangements simultaneously. Electrode pairs are located separately on dominant muscles(S-type arrangement), because the bandwidth of signals obtained from S-type placement is wider than that from C-type(closely in the region between muscles). From the result of EMG pattern recognition test, the proposed mIAR(modified integrated mean autoregressive model) technique improves the recognitions rate around 17-21％ compared with other the AR and cepstral methods.

• The Journal of Korean Academy of Prosthodontics
• /
• v.27 no.2
• /
• pp.37-52
• /
• 1989

The purpose of this study was to investigate the relationship between sternocleidomastoid (SCM) and masseter muscles during occlusal functions by means of EMG recordings of examined muscles. For the study, eighteen normal subjects were selected and the Bio-electric Processor EM2 (Myo-tronics Research, Inc., U.S.A.) with the surface electrodes was used to record the EMG activity from the right and left middle of masseter and insertion of SCM of each subject during right and left gum-chewing and isometric contraction by changing the biting force at right eccentric position of jaw. The amount of biting force ranged from 5 to 70kg during isometric contraction were measured by use of Jaw Force Meter. (Nihon Koden Kogyo, Japan.) The results were as follows: 1. The activity onset of SCM and masseter on the same side was almost at the same time, and integrated EMG values of two muscles on the chewing side were higher than the same named muscles on the non-chewing side during gum-chewing. (p<0.01) 2. The regression correlation was not present between both masseters (p>0.05), but between both SCM muscles or muscles of two kinds on the chewing or non-chewing side. ($p{\leqq}0.05$) 3. The integrated EMG value of SCM on chewing or non-chewing side were about 10 percent of that of ipsilateral masseter. 4. Mean voltage of each examined muscles were almost proportional to biting force during isometric contraction and the slope of voltage/biting force line was steepest at the ipsilateral masseter, followed by contalateral masseter, ipsi- and contra-lateral SCM muscles. 5. Mean voltage of ipsilateral masseter was highest during isometric contraction, followed by ipsilateral masseter, contra- and ipsi-lateral SCM muscles.

• Journal of the Ergonomics Society of Korea
• /
• v.8 no.2
• /
• pp.3-18
• /
• 1989

Two sets of isometric pushing and pulling experiments were performed by two male and two female susbjects. One set of experiments involoved isometric hand pushing and pulling in a standing erect posture, in which the thigh and pelvic regions of the subjects were braced to achieve the greatest strength. Another set of experiments involved isometric hand pushing and pulling in a free posture, in which the subjects elected their preferred postures to attain the largest strength at each of thred handle heights (low-66cm ; mid-109cm ; and high-152cm). It was shown from isometric pushing and pulling experiments in a standing erect poture that the rectus abdominis and the erector spinae muscles were acting as an antagonistic pair with respect to the L5/S1 intervertebral joint, and that the integrated EMG and the muscle force were linearly related. However, the relationships between the integrated EMG and the muscle force during isometric pushing and pulling in a free posture were not well-correlated. It is proposed that the integrated EMG results should be carefully interpreted for tasks of pushing and pulling at various handle heights.

• The Journal of Korean Academy of Prosthodontics
• /
• v.36 no.3
• /
• pp.427-452
• /
• 1998

To elucidate the effects of food texture such as hardness, cohesiveness, adhesiveness on mastication procedure, the electromyographic activity (EMG) of the masticatory muscles and the chewing movements were analyzed in eighteen young subjects during ordinary chewing. Seven different foods were selected by sensory texture profiling and mechanical test with texturometer; egg white, sausage, pizza cheese, yang-geng, biscuit, peanut and almond. The indexes of jaw movements used were the chewing number, chewing time, maximum opening, average opening, closing velocity and opening velocity. The EMG indexes analyzed were maximum and average integrated amplitude of the anterior temporal and masseter muscles. The results obtained were as follows. 1. The chewing time and chewing number, mandibular displacement and mandibular movement velocity were not changed by the hardness, cohesiveness and adhesiveness of the food (p>0.05). 2. The harder food materials showed a higher amplitude of the anterior temporal muscle integrated EMGs than the softer ones (p<0.05). 3. The maximum and average integrated EMGs of the masseter muscle increased with the increase of hardness of the food (p<0.05). 4. The integrated EMGs of preferred side and non-preferred side masticatory muscles increased with the increase of hardness of the food (p<0.05). 5. The adhesiveness and cohesiveness of the food were not the determining factor to the integrated EMGs of masticatory muscles (p<0.05).