• The Journal of Korean Physical Therapy
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• v.12 no.2
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• pp.153-163
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• 2000

This study was conducted to examine the relationship between limit of stability and age, height and weight. 83 healthy elderly(male 40, female 43) were measured the limit of stability and demographic characteristics. The results were as follows. 1. Left-right limit of stability was correlated with age in the elderly. 2. Left-right limit of stability was not correlated with the height, weight in the elderly. 3. Anterior-posterior limit of stability was correlated with age. height and weight in the elderly. So it is recommended that high risk groups - more aged people. of elderly should be offered the exercise program for increasing the limit of stability and well-designed studies of proper exercise program for musculoskeletal function and muscle power elevation should be performed.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.96-100
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• 2012

Low back pain (LBP) is a major issue in modern industrialized society which is mainly caused by manual material handling (MMH) tasks. The objective of this study was to provide scientific data for establishing work standard for Korean workers throughout the laboratory experiment including some specific lifting tasks. Thirty male college students were recruited as participants. The maximum voluntary contraction (MVC), recommended weight limit (RWL), and psychophysical safety weight using Borg's CR-10 scale were studied. Results showed that the RWL was 8.4% MVC higher than the proposed psychophysical safety weight. Based on this result, it is suggested that the NIOSH lifting equation (NLE) should not be directly applied to Korean without reasonable modifications. The ratio of psychophysical safety weight to MVC was ranged from 20.1 to 26.4%. It is expected that use of the methodology in this study may provide better expectation of the work ability of Korean for reducing lower back pains caused by MMH.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.1-23
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• 1998

Work-related Low Back Pain(LBP) is one of tile most important Issues in the field of industrial safety and health. Particularly, manual lifting is known as a major cause of work-related LBP and impairment. Total number of 163 manual lifting tasks in motor assembly processes were investigated. The 1981 and the 1994 equations developed by National Institute for Occupational Safety and Health(NIOSH) were applied to evaluate potential hazards of lifting-related LBP. Comparisons between the 19R I and 1994 NIOSH criteria were made. The relationships between the NIOSH criteria and lifting-related LBP were also analyzed. The results of this study are as follows: 1. The values of Action Limit(AL) by the NIOSH 1981 lifting equation. Recommended Weight Limit(RWL) by the 1994 equation and the weight of the load handled at each manual lifting task were shown log-normal distributions. 2. LI'(the weight of tile load/AL) and LI(the weight of the load/RWL) were calculated estimate the physical stress imposed by each individual lifting task. As a result. 76.7% of the total LI' value exceeded 1 and 12.9% exceeded 3, and 84.7% of the total LI values exceeded 1 and 20.9% exceeded 3. 3. Bus 2 Department showed the highest rate of LI'>1 and LI>1 and Bus 1 Department showed the highest rate of LI'>3 and LI>3 4. In general, the RWLs by the 1994 equation were found lower than the ALs by the 1981 equation. It is assumed to he resulted from the fact that the 1994 equation includes methods evaluating asymmetrical lifting tasks and lifts of objects with less then optimal hand-container couplings, and also covers a larger range of work durations and lifting frequencies than the 1981 equation. 5. Significant correlations were found between LI' and incidence of LBP (R=0.734, p<0.05). LI and incidence of LBP(R=0.671. p<0.10) and load-weights and incidence of LBP(R=0.797, p<0.05). 6. Control measures are required to achieve the value of LI less than 1 for some tasks having high LI values. Engineering control is highly recommended for some tasks having the value of LI above 3.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.176-182
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• 2005

American Conference of Governmental Industrial Hygienists (ACGIH) adopted the Lifting Threshold Limit Values ($TLVs^{(R)}$) in 2005 as a guideline for protecting the workers from work-related low back and shoulder disorders associated with repetitive lifting tasks. The TLVs consist of three tables with recommended weight limits for lifting tasks and their determination procedures are simple. The TLVs sans the material weight/the recommended values (LITLVs) were obtained from 45 lifting tasks in ship engine manufacturing factories. These values were compared and correlated with the Recommended Weight Limits (RWLs) and lifting indices (LIs) determined by the Revised Lifting Equation (LE) of the National Institute for Occupational Safety and Health (NIOSH). The average ratio, LITLVs/LIs, was 0.8 (LITLVs: $1.3{\pm}0.8$, LIs: $1.6{\pm}0.7$). Thus, the TLVs underestimated the risk than the LE. The LITLVs were highly correlated with LIs (r=0.82). The predicted value of LITLVs when LIs=1 wa 0.76. Using the predicted TLVs the higher risk ones of a large number of tasks can be screened to be further investigated.

• Journal of International Academy of Physical Therapy Research
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• v.9 no.4
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• pp.1669-1675
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• 2018

The present study aimed to investigate rapid weight loss (RWL) and consequent physical and psychological challenges among judo athletes at the national athlete training center in 2017. The following results were obtained. Judo athletes used weight loss methods such as "gradually reduce meal portion," "skip meals," "limit water intake," "wear sweat suit for training," and "use sauna," and had physical and mental distress from such unhealthy weight management practices. Information about weight loss was obtained from "colleagues or senior athletes," "Internet," and "head coach or coach," and not experts such as nutritionists or physicians. Thus, athletes are recommended to employ healthy weight control methods based on advice from experts, such as nutritionists and physicians.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.153-159
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• 2005

The purpose of this study was to assess the ergonomic risks of lifting tasks in a marine diesel engine manufacturing industry using the National Institute for Occupational Safety and Health(NIOSH) Revised Lifting Equation(NLE). Average Lifting Index(LI=Weight of Load/Recommended Weight Limit) of a total number of 45 lifting tasks was $1.6{\pm}0.7$. The LIs were above 1 at 34 tasks(75.6%), and above 2 at 11 tasks(24.4%). Parts management showed the highest average LI value (LI=2.3) in all departments, which resulted from high frequency and heave load of lifting. The common and significant ergonomic risk factors in the processes were the heavy weight of diesel engine parts and the long horizontal distance. In addition, some lifting tasks had such potential risk factors as the long vertical distance, the high frequency of lifts or the long work duration.

• The Journal of Dong Guk Oriental Medicine
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• v.11
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• pp.66-73
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• 2008

Objectives: The study was designed to evaluate the single dose toxicity of modified Bo-yang-Hwan-o-Tang (mBHT) in Sprague-Dawley (SD) rats. Methods: The mBHT was once administrated orally to both sexes of rats at dose 2,000 mg/kg body weight which are the recommended maximum limit dose for acute toxicity. We recorded clinical signs of toxicity, body weight, gross and histological changes in target organs for all rats. Results: Neither significant changes of body weight not death was observed during the observation period in mBHT-administrated rats. Neither significant toxic signs not histopathological changes were shown during the observation period. There were not observed significant gross abnormality between the control and mBHT-administrated rats. Conclusions: These results indicated that the toxicity of mBHT is greater than 2,000 mg/kg body weight in SD rats.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.69-75
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• 2009

It is well-known that lifting capacity of a worker is influenced by body posture during the task. When a task analyst make use of RULA and REBA Trunk and upper arm angles are recorded in a separate item. It means that the interaction between the angles of two body segments may be ignored in a final score. The NLE(NIOSH Lifting Equation) has been used to supplement this problem. However, there is no study to validate the result of RWL (Recommended Workload Limit) under the existence of interactions between trunk and upper arm angles. The goal of this study was to assess the effect of the interaction between trunk and upper arm angles. Three responses, including NMVC(normalized maximum voluntary contraction), RWL(Recommended Weight Limit) and subjective judgment in psychophysical method (Borg's scale), were recorded according to the combinations of three trunk angles and nine upper arm angles. The results showed that lifting capacity is highly influenced by interaction of two body segments(trunk and upper arm). It means that the task workload has to be analyzed along with the interaction of trunk angles and upper arm angles when the task analyst assesses potential risk factors on the postures. This study may be able to be a fundamental study to develop an assessment method for lifting task analyses according to body postures.

• Child Health Nursing Research
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• v.21 no.4
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• pp.320-330
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• 2015

Purpose: The purpose of this study was to investigate the use of schoolbags and the prevalence of musculoskeletal symptoms among elementary school children and to identify factors associated with relative schoolbag weight and musculoskeletal symptoms. Methods: A descriptive correlation study was conducted with 228 elementary school children in grades 4-6. A self-administered questionnaire was used for data collection. Descriptive statistics, t-test, ANOVA, $x^2$-test or Fisher's exact test, logistic regression analysis were used for data analysis. Results: Mean relative schoolbag weight (RSW) was 6.40%. Among participants, 13.2% carried more than 10% of their RSW. Only 49.6% of participants organized the contents in their school backpack correctly. Musculoskeletal symptoms were reported by 42.5% of participants. Results from logistic regression analysis identified grade was a significant factor predicting RSW, and gender, RSW, and using a locker were significant factors predicting musculoskeletal symptoms among schoolchildren. Conclusion: Although RSW of school children in this study was within the currently recommended load limit, a considerable proportion of school children were not following guidelines for safe schoolbag use. An effective schoolbag safety campaign for parents, students, and teachers needs to be developed and evaluated to prevent possible musculoskeletal symptoms related to schoolbag use.

• Geomechanics and Engineering
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• v.19 no.3
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• pp.255-268
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• 2019

Taking top-coal caving mining face (TCCMF) as research object, this paper considers the combination of top-coal and immediate roof as cushion layer to build the solution model of support resistance based on the theory of elastic foundation beam. Meanwhile, the physical and mechanical properties of coal-rock combination influencing on strata behaviors is explored. The results illustrate that the subsidence of main roof in coal wall increases and the first weighting interval decreases with the increase of top-coal and immediate roof thicknesses as well as the decrease of top-coal and immediate roof elastic modulus. Moreover, the overlying strata reflecting on support has negative and positive relationship with top-coal thickness and immediate roof thickness, respectively. However, elastic modulus has limit influence on the dead weight of top-coal and immediate roof. As a result, it has similar roles on the increase of total support resistance and overlying strata reflecting on support in the limit range of roof control distance. In view of sensitive analysis causing the change of total support resistance, it can be regards as the rank of three components as immediate roof weight > overlying strata reflecting on support > top coal weight. Finally, combined with the monitoring data of support resistance in Qingdong 828, the validity of support resistance determined based on elastic foundation beam is demonstrated, and this method can be recommended to adopt for support type selecting in TCCMF.