• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.79-85
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• 2009

In this study, the effects of psychosocial stress (box color and precision demand) on muscle activity were evaluated in laboratory setting. Eight subjects performed sagittally symmetric lifting tasks. Box color (yellow, black), precision demand (yes, no), and box weight (5%MVC, 10%MVC, 15 %MVC) were varied and surface EMG signals from seven muscles(medial deltoid right, biceps brachii right, lateral triceps right, latissimus dorsi right, erector spinae right, external oblique right, internal oblique right) were recorded. EMG signals were band-pass filtered($10{\sim}400\;Hz$), rectified, RMS smoothed and normalized (NEMG). Analysis of variance tests were conducted on the total NEMG (TNEMG: the sum of the seven muscles' NEMGs) and on the individual muscle's NEMGs. Box color had no effect on the TNEMG and on the seven muscles activities(p>0.05). When precision demand was required at the end point of lifts, the mean NEMG showed higher values than no precision demand conditions: TNEMG (14% increase) and medial deltoid(40% increase), biceps brachii(10% increase), lateral triceps(26% increase), latissimus dorsi(25% increase) muscles. Those increases showed more conspicuous as the box weight increased in the muscles of medial deltoid, lateral triceps, and latissimus dorsi.

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.65-82
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• 1996

This study was carried out to study the changing patterns in muscle activities in Angle's II and Class III malocclusion patients following activator therapy, To study the activities of anterior temporal(T.A.), masseter(M.M.), posterior temporal(T.P.), and anterior belly of digastric(D.A.) muscles, surface electrodes were placed on 15 Angle's Class II and 17 Angle's Class III malocclusion patients and following conclusions were obtained after electromyographic recordings were taken at prior to the activator therapy and at some time between 6 -12 month after the start of activator therapy. 1. Class II and Class III malocclusion groups, when compared to normal occlusiongroup, showed no significant differences during resting and swallowing. But significant differences were observed in masseter and posterior temporal muscles during clenching. 2. Most of the muscles studied showed a certain pattern, that is those groups whose pre-treatment E.M.G. were lower than the normal value showed significant increase after activator therapy, whereas those groups whose pre-treatment E.M.G. were higher than the normal value showed significant decrease after activator therapy. This pattern was observed in all of the muscle groups studied except T.A.(swallowing), T.P.(clenching) and D.A.(swallowing, clenching) in Angle's Class III malocclusion group and in Angle's Class II malocclusion group, above tendency were observed only in T.A.(swallowing), M.M.(resting, swallowing) and T.P.(clenching). This pattern was less obvious during clenching. 3. When E.M.G. activity after activator therapy between Angle's Class II and Class III malocclusion group was compared, Class III malocclusion group showed more increase during resting, and Class II malocclusion group showed more increase during swallowing and clenching excepting M.M. and D.A. respectively.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.133-140
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• 2003

In this study, muscle activity was measured using surface EMG (sEMG) during a voluntary maneuver (ankle dorsiflexion) in the supine position was compared pre and post gait training. Nine patients with incomplete spinal cord injury participated in a supported treadmill ambulation training (STAT), twenty minutes a day, five days a week for three months. Two tests, a gait speed test and a voluntary maneuver test, were made the same day, or at least the same week, pre and post gait training. Ten healthy subjects' data recorded using the same voluntary maneuvers were used for the reference. sEMG measured from ten lower limb muscles was used to observe the two features of amplitude and motor control distribution pattern, named response vector. The result showed that the average gait speed of patients increased significantly (p〈0.1) from 0.47$\pm$0.35 m/s to 0.68$\pm$0.52 m/s. In sEMG analysis, six out of nine patients showed a tendency to increase the right tibialis anterior activity during right ankle dorsiflexion from 109.7$\pm$148.5 $mutextrm{V}$ to 145.9$\pm$180.7 $mutextrm{V}$ but it was not significant (p〈0.055). In addition, only two patients showed increase of correlation coefficient and total muscle activity in the left fide during left dorsiflexion. Patients' muscle activity changes after gait training varied individually and generally depended on their muscle control abilities of the pre-STAT status. Response vector being introduced for quantitative analysis showed good Possibility to anticipate. evaluate, and/or guide patients with SCI, before and after gait training.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.191-203
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• 2000

This study was performed to investigate the relationship between vertical dimension during swallowing and speech pattern in patients with temporomandibular disorders. For this study, 33 patients with temporomandibular disorders(TMDs), namely, 17 patients with disc displacement with reduction and 16 patients with disc displacement without reduction, and 30 normal subjects without any signs and symptoms in the masticatory system were selected as the patient group and as the normal group, respectively. Biopak $system^{(R)}$(Bioresearch Inc., Milwaukee, USA) was used for recording of electromyographic(EMG) activity(${\mu}V$) of the anterior temporalis, the superficial masseter, the sternocleidomastoideus and the trapezius insertion muscle during swallowing, and of mandibular positional change with function time(sec.) during swallowing and speech. A sentence of 'Sue is missing her house' was used for observing of speech pattern. Comparison between the two groups and relationship of the mandibular positional change and the function time between during swallowing and during speech were analysed by SPSS windows program. The results of this study were as follows : 1. Mean EMG activity of the trapezius insertion during swallowing was higher in the patient group, and the value was $3.4{\mu}V$ in patients and $2.1{\mu}V$ in normal subjects. 2. Vertica1 dimension(VD) at mandibular rest position before swallowing was slightly higher in the patient group, but VD at swallowing-late stage and at rest position after swallowing were not different between the two groups. 3. Swallowing time were 2.1 sec. in the patient group, and 1.5 sec. in the normal group, and the difference was significant. 4. VD during speech were generally higher in the normal group. In this case, speaking position showing the most difference between the two groups was 'her' position. The distance from habitual intercuspal position to 'her' position was 4.9mm in the patient group, and 6.6mm in the normal group. Speaking time was also longer in the patient group. 5. There were no difference in all observed items between the two categories of the patient group according to reduction of disc displacement. 6. Relationship between the positional changes during swallowing and speech were different between the patient group and the normal group. And in the normal group, VD at rest position before swallowing was negatively correlated with speaking time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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• pp.78-84
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• 2009

The purpose of this study was to compare gait patterns during pregnancy. Because of the changes in hormone levels and anatomical changes such as body mass, body-mass distribution, joint laxity, and musculotendinous strength that result from pregnancy, it was possible that there would be certain gait deviations associated with these changes. Three-dimensional gait analyses were performed from a self-selected pace, and six subjects(height : $163{\pm}5.3cm$, mass : $61.3{\pm}3.80kg$, $65.3{\pm}5.14kg$, $70.2{\pm}4.98kg$) participated in the three times(the early, middle and last years). 7 cameras(Proreflex MCU-240, Qualisys) and 2 force plates (Type 9286AA, Kistler) were used to acquire raw data. The parameters were calculated and analyzed with Visual-3D and Joint moments computed using inverse dynamics. In conclusion, pregnant women's gait patterns were changed during pregnancy period because pregnancy makes them physical changes. The main changes were joint moments and kinematic factors during pregnancy period. The pregnancy transformed normal gait pattern Into toe out position. Therefore, exercise programs to improve muscle activity were necessary where joint moments were small. The development of simulator should be studied for pregnant women's tailored shoes and accessories in future.

• Sleep Medicine and Psychophysiology
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• v.11 no.1
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• pp.10-16
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• 2004

Sleep is associated with definite changes in respiratory function in normal human beings. During sleep, there is loss of voluntary control of breathing and a decrease in the usual ventilatory response to both low oxygen and high carbon dioxide levels. Especially, rapid eye movement (REM) sleep is a distinct neurophysiological state associated with significant changes in breathing pattern and ventilatory control as compared with both wakefulness and non-rapid eye movement (NREM) sleep. REM sleep is characterized by erratic, shallow breathing with irregularities both in amplitude and frequency owing to marked reduction in intercostal and upper airway muscle activity. These blunted ventilatory responses during sleep are clinically important. They permit marked hypoxemia that occurs during REM sleep in patients with lung or chest wall disease. In addition, sleep-disordered breathing (SDB) is more frequent and longer and hypoventilation is more pronounced during REM sleep. Although apneic episodes are most frequent and severe during REM sleep, most adults spend less than 20 to 25% of total sleep time in REM sleep. It is, therefore, possible for patients to have frequent apneas and hypopneas during REM sleep and still have a normal apnea-hypopnea index if the event-rich REM periods are diluted by event-poor periods of NREM sleep. In this review, we address respiratory physiology according to sleep stage, and the clinical implications of SDB and hypoventilation aggravated during REM sleep.

• Journal of muscle and joint health
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• v.3 no.1
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• pp.50-62
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• 1996

The purpose of this study was to identify and construct a substantive theory about the experience of fatigue among the female elderly with osteoarthritis. The interviewees were 6 female elderly with osteoarthritis. Of them 3 were admitted General hospital, the remaining 3 didn't admitted hospital. The data were collected through in-depth interviews by the investigators from May 20th, 1995 to June 19th, 1995. The collected data were coded into concepts and categories according to Strauss & Corbin's grounded method. The data thus collected were analyzed immediatly after interviews and fed into next round of interviews until the data collection reaches the saturation point where no additional concepts emerge. The 35 concepts were from analyzing the grounded data. The results of this study were as follows : 'change of the health condition','change of the life pattern', 'physiologic change', 'change of the coping pattern', 'performance of homework', 'activity daily living', 'tireness', 'ache', 'change of general apperance', 'sleep disturbance', 'powerlessness'. 'Physiologic unbalance', 'change of the family dynamics', 'physical imbalance', 'loss of the control', aviodance', 'conversion', 'leaving', 'indifference', 'hesitation', 'the pursue of information and trial', 'the western therapy', 'heat therapy', 'the oriental therapy','exercise', 'weight control', 'support', 'solution', 'being as before', 'adding more'. Six categories emerged from the analysis of ground data. They were as follows : 'stimuli', 'fatigue', 'passive coping', 'active coping', 'disolution', 'remains'. 13 hypothesis were derived from the integration of categories as follows : 1. The stronger the stimulus as perceived by the subjects, the more the fatigue will exrerience. 2. The more severe the fatigue, the more severe the tireness. 3. The more severe the fatigue, the more the hardness. 4. The more severe the fatigue, the more the variability of appear will experience. 5. The more severe the fatigue, the more the pain will experience. 6. The more severe the fatigue, the more the insomnia will experience. 7. The more severe the fatigue, the more the powerless will experience. 8 The more severe the fatigue, the more the psychological unbalance will experience. 9. The more severe the fatigue, the more variability of the family dynamics will experience. 10. The more severe the fatigue, the more the physical unbalance will experience. 11. The more severe the fatigue, the more loss of control will experience. 12. The subjects who experienced the fatigue will be to show passive coping and active coping mechanism.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.235-243
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• 2011

The purpose of the study was to examine the thickness of the trunk muscles ie. external obliques (EO), transversus abdominis (TrA), and multifidus and the trunk endurance strength in order to determine any relationship between the presence or absence of low back pain (LBP) and the size of trunk muscles. Data were obtained from 50 subjects, aged between 19-29 years. Participants had no experience of spinal problems that had resulted in a restriction of normal activity or time-off work and no current spinal symptoms. Measurements of muscle thickness of the trunk muscles were collected at rest, contraction and 15 seconds of post contraction during endurance strength tests. Background information was obtained followed all physical measures. Subjects were divided into two groups based on their experience of LBP. In draw-in maneuver, increasing the thickness of TrA was observed in all participants while EO was decreased at contraction in group 1 and increase in group 2. Only subjects in the group 2 had TrA increased during the flexion endurance test. In the side-bridge endurance test, the thickness of the right TrA was also observed differently between groups. Therefore, the results of the study may suggest that a function of specific muscle should be addressed for training persons with LBP.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.207-214
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• 2010

The aim of this study was to investigate upper and lower limb muscle activity using EMG(electromyogram) sensors while walking and identify normal gait pattern using FSR(force sensing resistor) sensor. Fifteen college students participated in this study and their EMG and FSR signal were measured during stopping and walking trials. EMG signals from upper(pectoralis major and trapezius) and lower limbs(rectus femoris, biceps femoris, vastus medialis, vastus lateralis, semimembranosus, semitendinosus, soleus, peroneus longus, gastrocnemius medialis, and gastrocnemius lateralis) were obtained using the surface electrodes. FSR measured pressures on 8 areas of the sole of the foot during walking. EMG results showed that all muscle activities except for vastus lateralis and semimembranosus during walking had higher amplitudes than stopping. Additionally, muscle activities associated with stance and swing phase during walking were identified. Results on FSR showed that stance and swing phases were detected by FSR signals during a gait cycle. Eight gait phases－initial contact, loading response, mid stance, terminal stance, pre swing, initial swing, mid swing, and terminal swing- were classified.

• Korean Security Journal
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• no.19
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• pp.207-223
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• 2009

The main purpose of this study was to analyze the reaction time of body guards in different stances to provide quantification of data for educational use. There were 4 martial art trained body guards participating in this study. The results of the EMG analysis and reaction time are as follows. The average reaction time of the whole body was $1.38{\pm}0.07$ seconds. In the first phase the reaction to the signal was $0.22{\pm}0.02$ seconds while in the second phase the reaction after checking was $0.62{\pm}0.10$ seconds, which produced the largest impulse. the reaction times of the third and fourth phase were gradually reduced, $0.29{\pm}0.02$ seconds and $0.26{\pm}0.02$ seconds consecutively. In the body guard posture the following muscles had a high activity level; phase one the right and left of the tibialis anterior muscle, phase two the right and left of the tibialis anterior muscle and the right of the gastrocnemius, phase three the right side of the tibialis anterior and gastrocnemius, phase four the left and right of the biceps femoris and the right side of the rectus femoris. In the first and second phase the shank muscles were used a lot, whereas in the third and fourth phase the shank and thigh muscles were used a lot showing the overall muscle activation of the lower limbs.