• 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.

• 수산해양교육연구
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• 제27권2호
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• pp.537-545
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• 2015

The purpose of this study is to investigate how effects creatine dosage has on the improvement of rowing athletes' performance ability. Rowing athletes were administered with creatine, through which to examine the change of athletic performance ability, blood fatigue substances, and muscular activity. The subjects (participants) of this Study consisted of 12 male rowing athletes at P University, with at least 5 years of rowing experiences, which divided into two groups - creatine dosing group of 6 persons and control group of 6 persons - for random sampling measurement. Enzymatic-colorimetric method using lacrate oxidase and 4-aminoantipyrine was performed for blood lactate level analysis, and wireless EMG system (QEMG-4: Lxtha Korea) for muscular activity analysis, with 4 channels set for data analysis. As body parts to be measured, two muscular parts - latissimus dorsi and lumbar spinel - were chosen. Then, on the 5th day from the date of administering them with creatine (that is, 4 days after dosing them with creatine), rowing movement with the highest level of activity was calculated as peak value, which was measured twice. The test data used for this Study were SPSS/PC 18.0, pre-movement and post-movement two-way ANOVA for repeated measurement for comparative analysis of each muscle, with significant level at .05. As a result, the change of blood lactate level was significantly higher in creatine dosing group than in non-dosing group (p<.05). As for the change of muscular activity, both latissimus dorsi and lumbar spinel showed a significantly higher change of muscle in creatine dosing group than in non-dosing group (p<.05 and p<.05, respectively).

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.832-839
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• 2007

In this study, a new bicycle system was developed to improve muscular strength using the Magneto-Rheological(MR) rotary brake. The friction load of the MR rotary brake is adjusted according to muscle strength of the subjects. The characteristic of muscular strength was studied with various friction loads of MR rotary brake. The friction load was occurred with the current, applied to the MR. rotary brake. Experiments was composed of several cycling trials for various friction loads. In training programs involving muscle improvement, it is necessary to confirm muscle activity and fatigue. To measure the muscle activity and fatigue, EMG signals of rectus femoris (RF), biceps femoris (BF), tensor fasciae latae (TFL), vastus lateralis (VL), vastus medialis (VAS), gastrocnemius (GAS), tibialis anterior (TA) and soleus (SOL) muscles were collected with surface electromyography and analyzed into time and frequency domain. The experimental results showed that the muscle activity according to the applied current to the MR rotary brake was significantly different. The more the current was applied, the higher value of the integrated EMG (IEMG) was obtained. Especially, the magnitude of IEMG of the RF, BF, TFL and VL varied in direct proportion to the current. However, there was not significant in the median frequency as the cycling time continue.

• 한국안전학회지
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• 제38권6호
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• pp.16-25
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• 2023

This study investigated health problems and work-relatedness for fishermen. In total, 121 fishermen (103 males and 18 females) were extracted from the data of the 6th Korean Working Conditions Survey. Two groups (Symptomatic and Asymptomatic) were statistically compared in terms of health problems and exposure to hazards. The most common health problems identified for fishermen were muscular pain in the shoulder, neck, and upper limbs (73.6%), backache (71.1%), muscular pain in the lower limbs (58.7%), overall fatigue (33.9%), headaches or eyestrain (22.3%), and anxiety (8.3%). These health problems were found to be related to the working conditions of the fishermen (low temperatures, tiring or painful postures, stance, sitting position, repetitive hand or arm placement, and the experience of stress). This study's findings may help us better understand the characteristics of the health problems and work-relatedness of fishermen and could be helpful for improving fishermen's overall health and safety.

• Physical Therapy Rehabilitation Science
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• 제7권3호
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• pp.127-133
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• 2018

Objective: The purpose of this study was to investigate the effects of foam roller (FR) stretching, kinesiotaping (KT), and dynamic stretching (DS) on gait parameters after inducing muscle fatigue in the ankle joint. Design: Cross-sectional study. Methods: The subjects were thirty healthy young adults between the ages of 20 and 31 years at Baekseok University who voluntarily participated in this study. The participants were randomly assigned to either the FR group, KT group, or the DS group after inducing muscle fatigue of the ankle joint. Fatigue induction of the ankle joint muscles was performed by alternating a heel up and down exercise with the standing posture on the ground. The speed was maintained at 40 beats/minute using a metronome. Subsequently, the respective intervention was applied to each group. Gait parameters were measured before and after ankle muscle fatigue induction, and after intervention using the GAITRite system. One-way ANOVA was used to compare gait parameters among groups, while repeated measures ANOVA was used to compare gait parameters within each intervention group. Results: The FR group increased significantly in velocity, step length, and stride length except for cadence after intervention compared to after ankle muscle fatigue induction (p<0.01). Furthermore, the KT group showed significant increases in velocity, cadence, step length, and stride length after intervention, especially in cadence group (p<0.05). All intervention groups showed significant increases in stride length after intervention, especially the DS group (p<0.05). Conclusions: Therefore, we suggest that KT, FR, and DS can be an effective intervention on gait parameters when the ankle joint is unstable and injured.

• 한국직업건강간호학회지
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• 제31권2호
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• pp.95-103
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• 2022

Purpose: This study aims to identify general, workplace, and health-related characteristics of outdoor workers exposed to high temperatures, and to compare the risk of disease according to outdoor high temperature exposure. Methods: This secondary analysis study used the 5th Korean Working Conditions Survey (2017) to identify 4,915 outdoor workers exposed to high temperatures. Results: Outdoor workers exposed to high temperatures were mostly male, elderly, less educated, and daily contract workers. Most of them were engaged in agriculture, forestry and fishing, and construction industries. About 40~50% of them complained of musculoskeletal pain and overall fatigue. The results showed that high temperature exposure increased the risk of illness (hearing problem, skin problem, backache, muscular pains in upper and lower limbs, headache/eyestrain, injuries, depression, and overall fatigue) among workers. Conclusion: High temperature exposure might increase the risk of illness among workers. The results of this study demonstrated that the outdoor workers should be protected from high temperatures.

• 한국치위생학회지
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• 제13권4호
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• pp.651-657
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• 2013

Objectives : The purpose of the study is to verify the correlation between teenagers' use of internet and temporomandibular joint disorders(TMJD) because TMJD patients gradually increase in high school students. Methods : Subjects were 221 male high school students attending liberal arts and commercial schools from 9 to 21 of April, 2012. Students completed self-reported questionnaire. Results : TMJD symptoms included crackling joint (32.1%), headache (18.6%), malocclusion (8.1%), and jaw fatigue and muscular aching (7.2%). Students having at least one symptom accounted for 49.8%. Students having at least one poor habit accounted for 83.7% and 34.0% of the students used internet for 3 hours.. Score of students experiencing shoulders and chest pain was $5.13{\pm}1.10$ (p<0.05). Score of TMD afflicting area revealed $4.67{\pm}2.73$ (p<0.05) in mastication pain ($4.13{\pm}2.73$ (p<0.05)) due to long hours of internet use. Score of jaw fatigue related to muscular pain was $4.31{\pm}1.96$ (p<0.01). Duration of computer use was related to perceived TMJD symptoms (r=.153). Long duration of computer use was related to poor oral cavity habits (r=.157). Conclusions : Male high school students can perceive slight TMD which needs self management and regular check-ups and try to prevent TMD by utilizing measurement tools on TMD. Also, this study helps to prevent from worsening TMD by shortening hours of computer utilization.

• 대한한방부인과학회지
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• 제29권2호
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• pp.83-98
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• 2016

Objectives: This Study was designed to investigate the effect of Oxygen chamber to recover muscle fatigue. Methods: Twenty Subjects were divided into Oxygen Chamber Group (n=10) and Rest group (n=10). Subjects visited hospital two times, blood tests were performed 3 times for each visit. 1st blood test was performed in 4 hours hunger state. 2nd blood test was performed within 5 minutes after the 6 minutes bike exercise. 3rd blood test was performed after the 40 minutes Oxygen treatment or 40 minutes rest in bed. Blood test items were Lactate, Glucose, Lactate Dehydrogenase, Creatine Kinase, Free Fatty Acid. 2nd visit was applied 1st visit process, But Oxygen Chamber group was crossed over to Rest Group, Rest Group was crossed over to Oxygen Chamber group. The Blood test result was analyzed with paired T-test using SPSS for Windows version 21. Results: The reduction of Lactate in Oxygen Chamber Group (6.86±2.07 mmol/ℓ) was higher than Rest group (6.57±2.33 mmol/ℓ), but it was not statically significant (p=0.68). The reduction of Glucose in Oxygen Chamber Group (6.85±12.14 mg/dl) was lower than Rest group (7.60±9.83 mg/dl), but it was not statically significant (p=0.83). The reduction of Lactate Dehydrogenase in Oxygen Chamber Group (16.10±14.91 mmol/ℓ) was lower than Rest group (19.75±12.46 mg/dl), but it was not statically significant (p=0.41). The reduction of Creatine Kinase in Oxygen Chamber Group (13.40±5.69 U/ℓ) was lower than Rest group (15.25±8.01 U/ℓ), but it was not statically significant (p=0.41). The reduction of Free Fatty Acid in Oxygen Chamber Group (285.50±174.13 uEq/ℓ) was higher than Rest group (196.15±131.58 uEq/ℓ), but it was not statically significant (p=0.07). Conclusions: This study showed Oxygen chamber therapy could be effective to recover muscle fatigue.

• 한국정보통신학회논문지
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• 제14권5호
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• pp.1231-1239
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• 2010

이에 본 연구에서는 비침습적인 방식으로 국소적 부위인 경혈과 Trigger Point에서 경결된 근조직과 신경조직을 자극할 수 있는 자기장 자극 시스템을 제작하였다. 시스템을 이용하여 가정용 저주파치료기기와 동일한 조건에서 상완 이두박근의 근피로 유발 후 근피로 회복을 평가하였다. 경혈과 Trigger Point의 해부학적 위치가 동일한 청영혈(HT2)를 자극위치로 선정하였다. 등척성 운동을 통하여 25명의 일반인에게 근피로를 유발시켰으며, 무자극 5명, 저주파 치료기기의 전기자극 10명, 자기장 자극 10명으로 분류하였다. 자극시간은 5분으로 하여 자극하였으며, 5일동안 EMG를 측정하여 관찰하였다. EMG를 주파수영역에서 분석해본 결과, 무자극의 근피로 회복률이 가장 저조했으며, 저주파치료기기의 전기자극보다 자기장 자극이 근피로 회복에 효과적인 것으로 확인되었다.

• 대한물리치료과학회지
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• 제29권1호
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• pp.73-86
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• 2022

Background: The purpose of this study is to investigate the effect of plantar flexor on muscle fatigue and endurance when two different sport tapes are applied. Design: Cross-sectional design. Methods: Fifty-one healthy adults were randomly assigned to dynamic taping group (n=17), kinesio taping group (n=17), and control group (n=17). The dynamic taping group used the dynamic tape. The kinesio tape group used the kinesio tape, and the control group doesn't used tape. Every group performed heel rise test and sEMG for every during pre-test and post-test. To evaluate plantar flexor endurance, the number of times was measured during the heel rise test. Results: The number of heel rises increased significantly in the post-test in dynamic taping group compared to the pre-test, and In comparison between groups, the number of heel rises significantly increased in dynamic taping group compared to kinesio taping group and control group. PEF value was significantly increased in the post-test compared to the pre-test in dynamic taping group, and there was a significant difference between the three groups according to the taping application. Conclusion: The results of this study confirmed that dynamic taping was effective in musclular fatigue and endurance on plantar flexor in healthy adults. Based on these results, it is suggested that the application of dynamic tape can be suggested as one of the intervention methods for muscle endurance and muscle fatigue.