• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4629-4635
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• 2012

This study was aimed at the relationship between peak EMG amplitude on low back muscles acting on L5/S1 and load center of gravity, trunk lateral bending while lifting an object. Musculoskeletal disorders including low back pain can occur even when handling heavy objects only once as well as when doing non-heavy materials repeatedly. 11 male subjects with average 23 age were required to lift a 15.8kg object symmetrically three times. Peak EMG amplitudes on 6 muscles related with L5/S1 were recorded and analyzed. The lifting conditions consisted of lifting symmetric load with no trunk lateral bending, asymmetric load with no trunk lateral bending, and asymmetric load with trunk lateral bending to the load center of gravity within an object. The results showed that peak EMG amplitude on back muscles contralateral to load center of gravity was observed greater in comparison with the symmetric load. Also, in case of lifting asymmetric load the posture with trunk lateral bending increased peak EMG amplitude on muscles contralateral to load center of gravity more than with no trunk lateral bending. This research can be used as one administrative intervention in order to reduce the low back pain incidence with suggesting workers that they keep the trunk not bending to load center of gravity if possible when lifting a heavy asymmetric object.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.219-233
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• 2004

The purpose of this study was to compare the EMG activities of four-forearm muscles during Kumdo head striking. The four skilled and unskilled Kumdo club members were selected from D university in B city. Investigated muscles were left brachioradialis, right brachioradialis and left flexor carpi radialis, right flexor carpi radialis. Raw EMG data were collected during the head striking motions and the average EMG were calculated by the frame width of 0.05s, and then the average %MVC were calculated. The average %MVC values of each muscle in each group were compared. The results are as follows. 1) In each group, there were no significant statistical differences between every muscle over the all phases. 2) There were significant differences, however, between skilled group and unskilled group. The former got higher average %MVC at left flexor carpi radialis and the latter at right brachioradialis in the ready phase and in the impact phase.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1246-1254
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• 2009

The reproducibility of initial value and change over time of surface EMG spike variables(MSA, MSF, MSS, MSD) was investigated in the biceps brachii muscle of 11 healthy subjects. Surface EMG signals were recorded during sustained isometric voluntary contractions for 30 seconds at three contraction levels, 20%, 50%, and 80%MVC, respectively. Each contraction was repeated three times in each of three different days for a total of nine contractions and 99 contractions per %MVC level across the eleven subjects. A total of 297 EMG signals across the different trials, days, subjects, and %MVC levels was saved for the subsequent analysis. The degree of reproducibility was investigated using the intraclass correlation coefficient(ICC) and the standard error of the mean(SEM) based upon the analysis of variance(ANOVA), Results for intercept showed higher reproducibility of the spike variables with about 60%-98% ICC than the variable(ARV, MNF) which had been analyzed before in other researches. And results for slope showed poor reproducibility of the spike variables with about 30%-70% ICC and they were comparable with the variables of other researches.

• The Journal of the Acoustical Society of Korea
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• v.21 no.2
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• pp.128-133
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• 2002

We developed a electronic music glove (BMG) system that plays musical scores in real time processing. The EMG system interfaces with the signal coming from the controller to the sound card in the computer, The computer, according to the status of the fingers and foot switches, generates the sound signals and sends them to the speaker systems through the application C++ program and MIDI message. The EMG systems control the velocity and duration of sound and several musical performance expressions such as chorus, reverberation, rhythm, and volume. Finally, we implemented the digital drum set using: the EMG system as example.

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

• Physical Therapy Korea
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• v.4 no.1
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• pp.78-86
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• 1997

Back muscles play an important role in protecting the spine. Epidemiological studies have shown that loads imposed on the human spine during daily living play a significant role in the onset of low back pain. No previous study has attempted to correlate the response of the trunk musculature with the type of external load. The purpose of this study was to use surface electromyography (EMG) to quantify the relative demands placed on the back muscles while lifting loads in one hand. Forty asymptomatic, twenty year-old subjects stood while lifting loads of 10% of body weight(BW) unilaterally. All EMG data were normalized to a percentage of the EMG voltage produced during no-load standing(%EMG). Our major analysis involved a paired t-test for repeated measures. Of particular note was the fact that the ipsilateral 10% of BW condition produced statistically less % EMG change than did the contralateral 10% of the condition.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.31-46
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• 2002

The purpose of this research is to provide scientific training guides and the basis for preventing injuries in performing tango backward walk by comparing the effects the height and shape of a heel will have on leg muscles and determining the difference between skilled and unskilled dancers through EMG analysis according to different types of shoes Total eight female athletes were selected for this research. Four with six years of professional dancing experience and another four with one year of dance sports experience. Utilizing the EMG system, rectus femoris, biceps femoris, anterior tibialis, gastrocnemius were measured under different heights (0cm, 5cm, 7cm, 9cm) and shapes (flat, fine, wide) of a heel. Experiments were conducted calculating EMG peak value and muscle load ration under different types of shoes in order to analyze the EMG of leg muscles and Erector Spinae when performing tango backward walk. The result was as follows: 1. The EMG peak value of leg muscles showed significant difference under different heights of a heel in anterior tibialis(p<.001) and gastrocnemius(p.<01) in case of skilled dancers, and in biceps femoris(p.<01) in case of unskilled dancers. 2. The EMG peak value of leg muscles showed significant difference under different shapes of a heel in anterior tibialis(p<.001) and gastrocnemius(p<.001) in case of skilled dancers, and showed no significant difference in case of unskilled dancers. 3. The muscle load ration of leg muscles showed different degrees of muscle contribution between skilled and unskilled dancers. The muscle load ration was in the order of anterior tibialis, rectus femoris, biceps femoris, and gastrocnemius in case of skilled dancers and anterior tibialis, gastrocnemius, biceps femoris, and rectus femoris in case of unskilled dancers.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.1
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• pp.43-48
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• 2009

Purpose : The purpose of this study is to determine the effects of high heeled shoes on the static balance and EMG activity of lower extremity muscles. Methods Twenty subjects were composed of control group(wearing low-heeled shoes) and experimental group(wearing high-heeled shoes). Two groups participated in bearfoot standing and measured static balance and EMG activity of lower extremity muscles. Balance Performance Monitor(BPM) was used to measure the static balance and FlexComp $Infiniti^{TM}$ was used to measure the EMG activity of lower extremity muscles. Results In static balance, sway area and path of experimental group was significantly larger than control group(p<0.05). And sway velocity of experimental group was significantly faster than control group(p<0.05). They means static balance of experimental group was significantly lower than control group(p<0.05). In EMG activity, L5 paraspinalis and biceps femoris of experimental group was significantly more increased than that of control group(p<0.05). Conclusion : The long-time experience in wearing high heeled shoes may have caused change in static balance and EMG activity of lower extremity muscles.

• Journal of Convergence for Information Technology
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• v.7 no.4
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• pp.159-164
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• 2017

The aim of this study was to investigate the effects of scapular dynamic stabilization exercise(SDex) with electromyography(EMG) biofeedback on the upper trapezius(UT), pectoralis major(PM) and serratus anterior(SA) activities. Fifteen healthy male voluntarily participated in this study. A paired t-test was used for statistical analysis. The study showed, through EMG biofeedback, that EMG activity significantly decreased in the UT, PM and increased in the SA(P<0.05). These results suggest that SDex with EMG biofeedback is effective to selectively strengthen the SA. This article is meaningful in that it is the first article using SDex with EMG biofeedback.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.45-52
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• 2007

Recently, overweight that is the major cause of diseases is troubled about the serious social problems. To solve this problem, the need of measurement system for the overweight management has been increased. This paper is the study on measurement system. This system analyzes EMG (electromyograph) of the abdomen. Then, checks one's state of health and offers the right medical services wherever and whenever. To analyze EMG of the abdomen, this paper proposes the algorithms that are energy detection, feature detection, classification and recognition, etc. Measurement system based on the analysis algorithms of EMG appraises overweight and physical strength of the abdomen. It also provides the right estimation for one's state of health.