• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.24.1-24.15
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• 2023

Background: The construction workers are vulnerable to fatigue due to high physical workload. This study aimed to investigate the relationship between overwork and heart rate in construction workers and propose a scheme to prevent overwork in advance. Methods: We measured the heart rates of construction workers at a construction site of a residential and commercial complex in Seoul from August to October 2021 and develop an index that monitors overwork in real-time. A total of 66 Korean workers participated in the study, wearing real-time heart rate monitoring equipment. The relative heart rate (RHR) was calculated using the minimum and maximum heart rates, and the maximum acceptable working time (MAWT) was estimated using RHR to calculate the workload. The overwork index (OI) was defined as the cumulative workload evaluated with the MAWT. An appropriate scenario line (PSL) was set as an index that can be compared to the OI to evaluate the degree of overwork in real-time. The excess overwork index (EOI) was evaluated in real-time during work performance using the difference between the OI and the PSL. The EOI value was used to perform receiver operating characteristic (ROC) curve analysis to find the optimal cut-off value for classification of overwork state. Results: Of the 60 participants analyzed, 28 (46.7%) were classified as the overwork group based on their RHR. ROC curve analysis showed that the EOI was a good predictor of overwork, with an area under the curve of 0.824. The optimal cut-off values ranged from 21.8% to 24.0% depending on the method used to determine the cut-off point. Conclusion: The EOI showed promising results as a predictive tool to assess overwork in real-time using heart rate monitoring and calculation through MAWT. Further research is needed to assess physical workload accurately and determine cut-off values across industries.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.69-80
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• 1998

This research was designed to investigate how the exercise program affects paraplegic standing and walking employing functional electrical stimulation(FES). Emphasis was also given to fatigue of major lower extremity muscles induced by different types of electrical stimulation. We applied continuous and intermittent rectangular pulse trains to quadriceps of 10 normal subjects and 4 complete paraplegic patients. The frequencies were 20Hz and 80Hz, and the knee angle was fixed at 90$^{\circ}$and 150$^{\circ}$to investigate how muscle fatigue is related to muscle length. The knee extensor torque was measured and monitored. We have been training quadriceps and gastrocnemius of a male paraplegic patient by means of electrical stimulation for the past two year. FES standing was initiated when the knee extensors became strong enough to support the body weight, and then the patient started FES walking utilizing parallel bars and a walker. We used an 8-channel constant-voltage stimulator and surface electrodes. The experimental results indicated that paralyzed muscles fatigued rapidly around the optimal length contrary to normal muscles and confirmed that low frequency and intermittent stimulation delayed fatigue. Our exercise program increased muscle force by approximately 10 folds and decreased the fatigue index to half of the initial value. In addition, the exercise enabled the patient to voluntarily lift each leg up to 10cm, which was of great help to the swing phase of FES walking. Both muscle force and resistance to fatigue were significantly enhanced right after the exercise was applied every day instead of 6 days a week. Up to date, the patient can walk for more than two and half minutes at 10m/min while controlling the on/off time of the stimulator by pushing the toggle switch attached to the walker handle.

• Journal of agricultural medicine and community health
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• v.28 no.2
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• pp.15-29
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• 2003

Objectives: This study was done to find out fatigue and self-reported physical symptoms of Vinylhouse farmers. The results of this study could be used as a basic data to develop health promotion program for Vinylhouse farmers who are suffering from fatigue and physical symptoms. Methods: The 166 respondents, who were working in Vinylhouse and were living in a remoted area where the primary health post located, were participated in this study. Thirty: 30 items of self-reported fatigue scale was used to evaluate the farmers fatigue level which made by Japanese industrial and hygenic association(1988). Twenty four: 24 items of index used by researcher for self-reported physical symptoms was from Lee In Bae's(1999) modified Index which was originated from Cornell Medical Index(1949). Another questionnaires used in this study were developed by researcher through related documents. Results: The results of this study were as follows; Fatigue scores were high in accordance with women(t=-2.212, p<0.05), worse recognized health state(F=20.610, p<.001), lack of sleeping hours(F=3.937, p<0.05), eat irregularly(t=-3.883, p<0.001), don't take a bath after application of chemical(t=-2.950, p<0.01), working time per a day(F=5.633, p<0.01) & working time per a day in Vinylhouse(F=5.247, p<0.01) were long. Subjective physical symptoms were high in accordance with women(t=-3.176, p<0.01), worse recognized health state(F=35.335, p<0.001), and low education(F=3.467, p<0.05). eat irregularly(t=-3.384, p<0.01), alcohol drinking(t=-2.389, p<0.05). When farmers don't take a bath after application of chemical show high(t=-3.188, p<0.01). As a result, the factors affecting to Vinylhouse worker's health were irregular diet habit, scarce exercise, lack of proper rest, symptoms oriented from Vinylhouse work in contaminated environment with high temperature and humidity. Conclusions: Based on this study, health promotion program is necessary for Vinylhouse workers. Also, the development of continuously practical strategy of healthy life style including exercise and comprehensive health promotion program considered the country's social and cultural background are needed.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.203-210
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• 2016

Background: Korean Red Ginseng (KRG) is a well-known natural product with anticarcinogenic and antioxidant effects. We evaluated the antifatigue effect of KRG in patients with nonalcoholic fatty liver disease (NAFLD). Methods: Eighty patients with NAFLD were prospectively randomized to receive 3 wk of KRG or placebo in addition to counseling on healthy eating and regular exercise. Liver function test, proinflammatory cytokines, adiponectin, antioxidant activity, and fatigue score were measured and compared according to the body mass index between the KRG and placebo groups. Results: The liver function tests were significantly improved after 3 wk of treatment in both groups. The mean levels (at baseline and after treatment) of tumor necrosis factor-${\alpha}$ were $108.0pg/mL{\pm}54.8pg/mL$ and $92.7pg/mL{\pm}39.0pg/mL$ (p = 0.018) in the KRG group and $123.1pg/mL{\pm}42.1pg/mL$ and $127.5pg/mL{\pm}62.2pg/mL$ (p = 0.694) in the placebo group, respectively. There was a significant difference in change of adiponectin levels between the KRG ($7,751.2pg/mL{\pm}3,108.1pg/mL$ and $8,197.3pg/mL{\pm}2,714.5pg/mL$) and placebo groups ($7,711.6pg/mL{\pm}3,041.3pg/mL$ and $7,286.1pg/mL{\pm}5,188.7pg/mL$, p = 0.027). In patients with overweight, the fatigue score was significantly decreased in the KRG group ($35.0{\pm}13.2$ and $24.5{\pm}8.9$, p = 0.019). Conclusion: Our results show that KRG might be effective in reducing proinflammatory cytokine and fatigue in overweight patients with NAFLD, in addition to improvements in adiponectin levels.

• Sleep Medicine and Psychophysiology
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• v.19 no.2
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• pp.77-83
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• 2012

Objectives: Recent studies have reported a correlation between obstructive sleep apnea syndrome (OSA) and depression. In attempt to verify the suggestion that eveningness is related to depression, we examined the effect of morningness-eveningness on their depressive mood in patinets with OSA. Methods: The examination was based on the medical records and polysomnography reports of 211 OSA patients. Information was gathered from the patients who filled out the H$\ddot{o}$rne and Ostberg questionnaire (HOQ), profile of mood states-Korean version (K-POMS), and Epworth sleepiness scale (ESS). We compared mean values of K-POMS total, subscales of K-POMS, ESS, and OSA severity variables among the 3 morningness-eveningness groups (morningness, eveningness, and neither groups). Partial correlation analysis was performed between variables and ANCOVA was performed among the 3 groups after adjustment with age and weight. Results: There were significant negative correlations between HOQ and the followings : K-POMS total, POMS-T (tension-anxiety), POMS-D (depression-dejection), POMS-A (anger-hostility), POMS-F (fatigue-inertia), POMS-C (confusion-bewilderment), spontaneous arousal index, average O2 saturation. There were significant positive correlations between HOQ and the followings : POMS-V (vigor-activity), apnea-hypopnea index, respiratory arousal index, snore time. There were significant negative correlations between POMS-D and the followings : HOQ, POMS-V, stage 1 sleep (%), AHI, TAI (total arousal index), oxygen desaturation index, respiratory arousal index, neck circumference, average O2 desaturation, snore time (%). There were significant positive correlations between POMS-D and K-POMS total, POMS-T, POMS-A, POMS-F, POMS-C, sleep latency, stage 2 sleep (%), heart rate, spontaneous arousal index. There were significant differences in K-POMS total, POMS-T, POMS-D, POMS-F, POMS-C, spontaneous arousal index among the three HOQ groups in ANCOVA. Conclusion: The depressive correlates of OSA patients might be affected, not by excessive daytime sleepiness or OSA severity indexes, but by eveningness circadian characteristics. It would be important to take into account the morningness-eveningness tendency when we manage the depressive mood of OSA patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2436-2442
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• 2014

In this study, EEG, HRV, and Vibra image were compared and analyzed in the environmental test room due to variation of temperature. The condition of the environmental test room was in relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux] with setting up different temperatures from $18[^{\circ}C]$ to $31[^{\circ}C]$. At temperature $25[^{\circ}C]$, relative $M{\alpha}$ wave, relative $M{\beta}$ wave, $\frac{SMR}{\theta}$, and SDNN were revitalized, and both sides ${\alpha}$ wave asymmetry index $A_2$, HRT, stress index, and fatigue degree were decreased. Therefore, it was found that temperature $25[^{\circ}C]$ effects to increase the Neuro-energy like amenity, productivity, and concentration.

• Journal of Korean Medicine Rehabilitation
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• v.24 no.1
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• pp.93-100
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• 2014

Objectives To evaluate the clinical utility of MET performed on sternocleidomastoid muscle of acute nuchal pain patients, we measured a change of meridian electromyography. Methods We compared electrical activity before and after MET performed on sternocleidomastoid muscle of acute nuchal pain patients in same group (n=20) in isometric exercise state during five seconds. We analyzed amplitudes and areas of electrical activity and asymmetry index (AI). Results 1. After MET performed on sternocleidomastoid muscle of acute nuchal pain patients, maximum voluntary isomeric contraction (MVIC) was significantly increased more than before MET performed (p<0.005). 2. Comparing with before MET performed on sternocleidomastoid muscle of acute nuchal pain patients, muscle fatigue after MET performed on sternocleidomastoid muscle of acute nuchal pain patients decreased but there was no significant difference. 3. Comparing with before MET performed on sternocleidomastoid muscle of acute nuchal pain patients, asymmetry index (AI) after MET performed on sternocleidomastoid muscle of acute nuchal pain patients decreased but there was no significant difference. Conclusions According to above results, after performing MET on sternocleidomastoid muscle of acute nuchal pain patients, maximum voluntary isomeric contraction (MVIC) increased significantly, so it is certain that performing MET on sternocleidomastoid muscle has a clinical effect.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.3 no.1
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• pp.1-12
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• 2005

This study aimed at examining the maximal isometric contraction caused by voluntary exercise and at comparing its aspects of decrease and restoration in their different repeated application, as to the quadriceps muscles of thigh in the subjects composed of patients with spastic hemiplegia and normal adults. Using isokinetic exercise analyser(Biodex Medical Systems Inc., Biodex System 3PRO, U.S.A.), experiment was conducted as to the normal group composed of fifteen adults and the patient group composed of fifteen patients with spastic hemiplegia. As to each group, MVIC(maximal voluntary isometric contraction) of the quadriceps muscle of thigh caused by voluntary exercise and the aspects of decrease and restoration of the isometric contraction were examined with the method to induce isometric exercise, and their SDI(strength decrement index) and SRI(strength recovery index) were also calculated. The results can be summarized as follows: 1. As for decrease of maximal isometric contraction, both groups showed slow decrease in voluntary exercise, but the normal group showed rapid decrease later phase. 2. As for SDI, no significant differences could be observed in comparison between groups. 3. As for restoration of maximal isometric contraction, both groups showed slow restoration in voluntary exercise, but the normal group showed rapid restoration early phase. 4. As for SRI, comparison between groups showed significant differences in voluntary exercise. These results lead us to the conclusions that spastic muscle is characterized by slow decrease and restoration of MVIC in comparison with normal muscle in voluntary exercise.

• Journal of Acupuncture Research
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• v.29 no.4
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• pp.35-42
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• 2012

Objectives : This study was to observe clinical application of auto-microneedle therapy system (AMTS) in patients with peripheral facial paralysis. Methods : 27 peripheral facial paralysis patients were observed after taking AMTS at Facial Palsy Center, Kyung Hee University Oriental Medicine Hospital from March 1, 2011 to January 9, 2012. We assessed the symptoms of facial paralysis with Yanagihara unweighted grading system, Sunnybrook facial grading system(SBGS) and facial disability index(FDI), and observed adverse events and total safety of the treatment. Results : The scores of facial palsy scales increased after AMTS in Yanagihara grading system and Sunnybrook facial grading system. AMTS-related adverse events were mild pain(5.9%) and fatigue(3.5%), which needed no extra treatment. The total safety evaluation was between 'safe' and 'nearly safe' level. There were no other serious adverse events. In addition, patients were satisfied with subjective improvement including facial tingling and numbness. Conclusions : AMTS can be applied as an adjunctive treatment for patients with peripheral facial paralysis due to its safety and clinical usefulness. It is easier to stimulate wide skin area in a short time. Further clinical research is required to investigate the effectiveness of ATMS in a more rigorous RCTs.

• International Journal of Highway Engineering
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• v.12 no.1
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• pp.47-54
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• 2010

This study had a focus on investigating technical validity of Two-Lift Concrete Pavements which had never been constructed in Korea in order to olve the problem of existing concrete pavements. This study found out the application of Steel Fiber Reinforced Concrete (SFRC) which was one of ew techniques. Also, optimal steel fiber contents and pavement thickness were determined. This study also measured compressive strengths, lexural strengths, toughness indexes, tensile strengths and fatigue strengths to estimate the performance of SFRC of according to results of aboratory experiments, slumps and air contents of concrete specimens the standards satisfied and compressive strengths to open traffic. At bending ests, Toughness Index of SFRC increased but flexural strength didn’'t increase as compared with non-steel fiber concretes. And, energy absorption of SFRC was very good and SFRC showed improvement in freezing and thawing resistances. To complete this research, we will evaluate the pplication methods and performance of SFRC at field section.