• 대한인간공학회지
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• 제27권3호
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• pp.33-41
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• 2008

The goal of this study was to compare wrist posture, muscular loads and perceived comfort among wearable wrist rest (WR), general wrist rest(GR), no wrist rest(NR) during keyboard and mouse use. Thirteen subjects performed text editing task in three test conditions: wearable wrist rest(WR), general wrist rest(GR), no wrist rest(NR). During text editing task, the right wrist posture was recorded by an electrogoniometer and the muscle activity in upper trapezius, anterior deltoid, extensor digitorum, extensor carpi ulnaris were recorded by electromyography. After all of the tests, the subjects rated perceived comfort. Working with wearable wrist rest(WR), compared to no wrist rest(NR) and general wrist rest(GR), decreased wrist radial/ulnar deviation and also decreased muscle activity in upper trapezius and anterior deltoid. At the same time, in work with wearable wrist rest(WR), the subjects rated more comfort at 5 of 8 body locations(shoulder, upper arm, wrist, hand, body).

• Physical Therapy Rehabilitation Science
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• 제10권3호
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• pp.367-373
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• 2021

Objective: Short foot exercise(SFE) is frequently used to increase the medial longitudinal arch of the foot, as well as the intrinsic foot muscles. This studyinvestigated the effects of SFE onmuscular activity and the onset of contraction of the quadriceps femoris muscle during squats in healthypeople. It also aimed to compare and analyze the results with those of the general squat method and propose a more efficient squat method. Design: Cross-sectional study. Methods: This study compared 20 adults (male=10, female=10) who statisfied the inclusion criteria for the muscle activity and onset of the muscle contraction of the quadriceps femoris using surface EMG under two conditions: general squats and SFE squats. Results: Separate analyses and comparisons of the outcomes of the SFE squat and the general squat, showed a significant increase in the muscle activities of the rectus femoris and vastus medial muscles in both males and females (p<0.05). The onset of muscle contraction was significantly delayed for the vastus lateralis relative to that for the vastus medialis (p<0.05). However, it delayed significantly in females, but not in males. Conclusions: The SFE squats induced selective muscular activities of the rectus femoris and vastus medialis muscels and affected the onset of contraction of the vastus medialis and lateralis muscles.

• PNF and Movement
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• 제18권3호
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• pp.315-321
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• 2020

Purpose: Recent studies have indicated that applying different inclination angles and suspension devices could be a useful way of performing exercises that include the co-activation of the trunk muscles. Present study was to examine the influences of changes in the inclination angle during trunk muscle activity while engaging in a bridge exercise with a suspension device. Methods: 18 healthy, physically active male volunteers completed three trunk inclination angles (15°, 30°, and 45°) for bridge exercise variations. The surface electromyography responses of the rectus abdominis, internal oblique (IO), erector spinae (ES), and rectus femoris (RF), as well as the subjective difficulty (Borg RPE score), were investigated during these bridge exercises. Results: The bridge with a 45° inclination angle suspension significantly increased the muscular activities of the RA and RF and increased the Borg RPE scores (p<0.05). The bridge with a 15° suspension significantly elevated the ES activities when compared to the other conditions. Conclusion: The present study demonstrated that a higher inclination angle could not activate the overall trunk muscles during the bridge exercise. The RA and RF produced greater activation during the bridge exercise with the higher inclination angle. On the other hand, the activities of the erector spine were greater during the bridge exercise with the lower inclination angle. The present study suggests that applying a low trunk inclination angle for the supine bridge exercise is suitable for activating the erector spine muscles.

• 대한의용생체공학회:의공학회지
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• 제44권5호
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• pp.324-328
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• 2023

Excessive inflammation in the body causes immune cells to release cytokines that damage normal tissues and cells, leading to rheumatoid arthritis and sepsis. Pulsed magnetic field(PMF) stimulation has many applications in the treatment of neurological, muscular disorders and pain. Therefore, in this study, we aim to investigate the effect of PMF stimulation on the regulation of excessive inflammation in the overall immune system. Macrophages, a primary immune cell, and T cells, a secondary immune cell, were co-cultured in the insert wells under the same conditions, and then inflammation was artificially induced. The changes in inflammatory activity following PMF stimulation were measured by pH and IL-6 concentration. After inflammation induction, both cells became more acidic and increased IL-6 expression, but after PMF stimulation, we observed improved acidification of macrophages and T cells and decreased IL-6 expression. Our results showed that infected macrophages activated T cells and that the recovery of excessive inflammatory response regulation after PMF stimulation proceeded more rapidly in macrophages. Therefore, this study suggests that PMF has a positive anti-inflammatory effect on the overall immune system and thus has the potential to be used as a non-invasive therapy for the treatment of chronic inflammatory diseases.

• 대한후두음성언어의학회지
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• 제25권1호
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• pp.36-38
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• 2014

The patient suffered cardiac arrest 8 months before presentation. She has been suffering hoarseness and exertional dyspnea and nocturnal stridor. Upon flexible laryngoscopy, her vocal cords showed no motion and fixed in paramedian position. There was no causal finding on neck CT. EMG showed some muscular activity. Under the suspicion of crico arytenoid fixation, we performed suspension laryngoscopy, and found the arytenoid cartilage was fixed with short and stout scar, which was removed with scissors. Just after surgery she regained her voice and respiration.

• 대한정형도수물리치료학회지
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• 제4권1호
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• pp.7-20
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• 1998

Activity of the trunk muscles is essential for maintaining stability of the lumbar spine because of the unstable structure of that portion of the spine. The central nervous system deals with stabilization of the spine by contraction of the abdominal and multifidus muscles in anticipations of reactive forces produced by limb movement. Recent evidence indicates that the lumbar multifidus muscle and transversus abdominis muscle may be involved in controlling spinal stability. Stabilization training in neutral spine is an integrated approach of education in proper posture and body mechanics along with exercise to improve strength, flexibility, muscular and cardiovascular endurance, and coordination of movement.

• The Korean Journal of Physiology
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• 제17권1호
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• pp.37-43
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• 1983

Electromyographic analysis was made in the forearm to clarify the prime mover of the wrist joint in flexion and extension. Loads of 5 and 10 pounds were given to the hand during isometric and isotonic contraction. The results of this study were summarized as follows: 1) M. flexor carpi ulnaris and m. extensor carpi radialis acted as the prime mover during flexion and extension, respectively, of the wrist joint. 2) The flexor and the extensor of the forearm showed synergistic activities under isotonic contraction, but under isometric contraction the flexor only acted. 3) Muscular activity during the isotonic contraction slightly increased compared with the isometric contraction. 4) EMGs and integrated EMGs were somewhat enhanced as the load increased, but there was no significant difference between 5 and 10 pounds load.

• 전기학회논문지
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• 제59권8호
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• pp.1497-1505
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• 2010

The present study was performed to investigate the effect of aging on muscular activity of older subjects under the condition of fixed load muscle contraction. SEMG signals were recorded from old (46 women) and young (45 women) groups performing sustained isometric elbow flexion contraction with a fixed load during 30 seconds. Linear regression and mean square error (MSE) analysis with four characteristic variables (ARV, RMS, MDF, MNF) were used to compare the age-related difference (of local muscle fatigue and fluctuation of the amplitude and frequency) in the SEMG signal. The main results can be summarized as follows: During sustained muscle contraction with a fixed load: i) the MSE values of amplitude (ARV, RMS) and frequency (MDF, MNF) variables were more than 30% higher for the young than for the old adults; ii) the measures of local muscle fatigue (slope of the MDF and MNF) indicated greater fatigue in the old; and iii) the rate of increase of the SEMG amplitude was higher for the young than the old.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 춘계학술대회논문집
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• pp.10-16
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• 1997

The ride comfort is one of the most important indices which decide the quality of automotive seats. A subjective evaluation is the general method for comfort evaluation of automotive seats. But the subjective evaluation assess the individual sensibility using questionnaire. Therefore, a need to develop methodologies to obtain objective measurements of the fatigue evaluation is evident. In an effort to monitor muscle activity during driving electromyography (EMG) was employed. In an experimental setting the subjective evaluation was conducted using questionnaire under the static conditions (8 subjects) and the fatigue was induced in muscles using EMG under the dynamic conditions (2 drivers). The resultant EMG signals were then sampled for three different muscles. In test involving 2 subjects of similar size and build, utilizing four different automotive seats, test results support the use of EMG to quantify muscular fatigue as a viable means of objective evaluation for the different automotive seats.

• 생물정신의학
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• 제5권1호
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• pp.138-141
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• 1998

Neuroleptic malignant syndrome (NMS) is an uncommon but potentially fatal idiosyncratic reaction to neuroleptics, characterized by muscular rigidity, fever, autonomic dysfunction, and altered consciousness. The major theories to explain NMS is central dopaminergic blockade, but it is unclear. Risperidone is a new antipsychotic drug, a benzisoxazole derivative that blocks dopamine $D_2$ receptor and serotonin type 2 receptor. The comparatively greater serotonin-blocking activity is believed to give risperidone the specific property of not causing any more extrapyramidal side effects than conventional antipsychotics at the optimal dose of 4-8mg/day. It is postulated that risperidone is unlikely to cause NMS. Here, we report a case of risperidone induced neuroleptic malignant syndrome.