• 한국안전학회지
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• 제23권2호
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• pp.51-56
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• 2008

In these days, work-related musculoskeletal disorders(WMSDs) is one of the issues in the shipbuilding industry. As the number of injured workers and demands for worker's compensation have rapidly increased, improvement of work conditions and environments to prevent WMSDs has been more demanded. To reduce WMSDs' hazards in the shipbuilding industry, simulation technique which showed it's ability of increasing the manufacturing productivity was applied, because simulation technique has the evaluation ability for a worker's danger level of production process by RULA(Rapid Upper Limb Assesment). In this research, worker's altitude had modeled and worker's action has simulated. After the caution level was evaluated, we pointed out clues which had high workload. To reduce work-load, we applied ergonomic principles for improving working conditions and environments. Improved working conditions and environments were simulated using human modelling and simulation and their workload were evaluated again.

• 한국안전학회지
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• 제21권5호
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• pp.84-91
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• 2006

The purpose of this study was to find out morbidity rate and pattern of occupational disease and affect of variables related disease of Fishing sailors'. The subjects this study were 624 fisheries sailors' who took a safety education course in Korea Institute of Maritime and Fisheries Technology. This questionnaire was focused on finding the basic data for prevention of occupational disease and promotion health on the fishing sailors'. The collected data were analyzed by using descriptive statistics, Chi-square, cross tab by SPSS package. The result of this study are as follow. 1) The morbidity rate within recent 12 months was 70.2%. There were significant differences of occurred disease in age, rank, perceived health status, fatigue symptoms, rest time, workload, overtime duration 2) The more aging(p<0.01), perceived fatigue(p<0.01), workload(p<0.01), overtime(p<0.05) and the less perceived health status(p<0.01), rest time(p<0.01), the higher morbidity rate. 3) Considering disease unable to work more than 4 hour, the number of those who had musculoskeletal disease were 20.9%, which revealed the highest rate, digestive disease 14.3%, traumatic disease 13.5%.

• 한국전문물리치료학회지
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• 제14권3호
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• pp.9-15
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• 2007

The purpose of this study was to investigate electromyographic activities of the flexor digitorum superficialis (FDS) and the flexor carpi ulnaris (FCU) by the shape of the ultrasound head. Twelve healthy subjects participated and performed ultrasound therapy with a round head and a long handled head during each 5-minute application. Electromyographic activities of the FDS and FCU were recorded by surface electrodes and normalized by maximal voluntary isometric contraction (MVIC) values. There was no difference in the muscular fatigue of FDS and FCU as determined by the shape of the ultrasound head (p>.05). Without the shape of head, the mean power frequency decreased with the time. There also was no difference in %MVIC of the FDS and FCU as determined by the shape of the ultrasound head (p>.05), but the force exerted exceeded 20%MVIC. There was however a significant difference in the amount of cumulative workload of the FDS and FCU as determined by the shape of ultrasound head (p<.05). The workload was however not affected by the shape of the ultrasound head. Constant static grasp of ultrasound transducer head during ultrasound therapy is considered a high risk factor of work-related musculoskeletal disease.

• 문화기술의 융합
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• 제7권3호
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• pp.155-161
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• 2021

27개 사업장, 1897 근로자를 대상으로 근골격계질환 증상조사표를 받아 근골격계증상과 근로자 개인적 특성과의 상관관계를 분석하였다. 근로자의 근골격계질환 증상 유무는 한국산업안전보건공단의 근골격계부담작업 유해요인조사 지침에 따라 관리대상자 이상을 기준으로 했으며 개인적 특성으로는 작업자의 연령, 업무부담, 가사부담, 직장경력, 여가종류, 성별, 결혼유무로 구분하였다. 조사는 업무부담, 가사부담, 직장경력의 서열변수는 이분형 로지스틱 회귀분석을 통해 상관관계를 조사하였으며 그 외 명목변수는 교차분석과 카이제곱분석으로 해당 결과의 유의성을 확인하였다. 그 결과 작업자의 연령이 낮을수록, 업무부하와 가사부담이 높을수록, 여성일 경우, 여가활동을 가지지 않을 경우 근골격계질환 증상발현율이 높아진다는 것을 확인하였다. 그러나 본 연구의 결과를 다른 연구결과와 비교한 결과 조금씩 결과가 다른 점을 미루어볼 때 본 연구의 자료를 근골격계질환 예방의 개략적인 지표로써 활용할 수는 있지만 정량적 지표로써 활용하가 전 추가적인 연구가 필요할 것으로 사료된다.

• 대한인간공학회지
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• 제31권3호
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• pp.445-453
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• 2012

The aim of this paper was to prove that if the risk level in combined tasks was improved through evaluation of postural load of liquid weight measurement process, the workload level and ratio of exposure time would be changed, and the time of process would be seen concurrently. Background: According to results of epidemiological studies conducted by Korea Occupational Safety & Health Agency, 122 musculoskeletal disorders occurred during 1992 to 2008, in which manufacturing industry covers 96(78.7%) of total. However, this is an insufficient level and only occupies 39% based on the South Korea's manufacturing standard industrial classification(246 industries). Method: Firstly, the number of batches weighed on one day(460min) was investigated based on the work performed and Weight measured weekly. VCR recording was taken based on the level of liquid ingredients prescribed for 1batch using the Camcorder. After dividing a 356 sec video into 1 sec using the screen capture function in Gom player, the job classification was performed by analyzing the change of working postures, which revealed 148 working postures. Time measurement was decided by time of the postures was being maintained. Then, the REBA analysis was performed for the working postures. The ratio of Exposure time was calculated based on the measurement time and REBA Score. In addition, the recommendations were designed and implementation was carried out for the working postures with REBA Score higher than 3. Finally, after the intervention, REBA measurement, time measurement, and ratio of exposure time were calculated for the comparison of works before and after improvement. Results: The number of work elements was decreased by 30.4% from 148 to 103 after improvement. The results of time measurement showed that the time was reduced by 46.3% from 356 sec to 191 sec. And the ratio of exposure time was also improved by 52.1% from 0% to 52.1% after improvement. Conclusion: The reduction of time was found to improve the productivity of management. Furthermore, because the reduction of ratio of exposure time and the improvement of workload level are the improvement of discomfort, it would contribute to the improvement of the worker's psychological working posture. Application: These results would contribute to musculoskeletal disease prevention and management performance. Further studies for other industries would be needed based on this case study.

• 대한인간공학회지
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• 제30권6호
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• pp.749-755
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• 2011

Objective: The purpose of this study is to assess the reducing effect of workload on developed electro-motion scissors. Methods: To achieve this, we measured the pressure distribution, Joint angle of fingers and JSI(Job Strain Index) for electro-motion scissors and hand-operated scissor in objective assessment and surveyed the uncomfortable degree in subjective assessment. Results: As a result, The peak of pressure in the electro-motion scissors was generally lower than the hand-operated scissors. JSI and overall joint angle of fingers for the electro-motion scissors were remarkably lower than the hand-operated scissors. Also, the subjective uncomfortable degree showed that the uncomfortable point of electro-motion scissors were generally lower than the hand operated scissors. Conclusion: The impact of reducing the work load as well as distributing the pressure around the hand by using electro-motion scissors during grapes pinching was confirmed.

• 한국안전학회지
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• 제26권3호
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• pp.75-82
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• 2011

The objective of this study was to identify risk factors associated with the occurrence of musculo-skeletal symptoms of cashiers and provide suggestions for an improved workspace design. Workload and exertion of each task were measured using job analysis and posture analysis. The three most time-consuming tasks were waiting (43.8%), scanning (23.5%) and payment transaction (22.9%). It was analyzed that the workspace can be improved by applying Korean anthropometric data to the design of the desk height. The most common posture was a standing posture with neutral back, and bent lower arms and hands. Finally, it was revealed that 'scanning' and 'payment transaction' seemed more stressful than other operations. The result of the ergonomic evaluation would be a useful basis for designing an improved workspace.

• 한국안전학회지
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• 제23권5호
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• pp.119-124
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• 2008

Many automobile assembly workers often do several cycles of tasks continuously, i.e., without breaks, to get a longer break. This is not recommended since the dose of fatigue increases exponetially with time and it takes much longer time to recover. In this study, a laboratory experiment was conducted to investigate the effect of work/rest schedules on workload of a repetitive upper-limb task. Eleven male subjects participated in the experiment, in which simulated screw driving tasks were carried out repetitively with 3 different work/rest schedules: standard breaks(1 cycle of work at a time, 60 20-s breaks), medium breaks(5 cycles of work at a time, 12 100-s breaks), and long breaks(10 cycles of work at a time, 6 200-s breaks). The result showed that medium- and long-breaks schedules significantly increased the level of perceived discomfort and %HRR as compared to the standard-break schedule. The subjects' preference was not statistically different among work/rest schedules, which might be caused from the absolutely low level of workload of the experimental tasks. From the results, it is recommended to have frequent and shorter breaks rather than infrequent and longer breaks to decrease the level of physical workload. A more expanded studies, however, should be carried out to provide more practical safety guidelines on the work practice of continuous working without breaks among automobile assembly workers.

• Safety and Health at Work
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• 제12권2호
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• pp.225-229
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• 2021

Background: The socioeconomic burden of musculoskeletal disorders (MSDs) is significant, and kitchen work is a high-risk occupation for MSDs due to the intensive manual workload and repetitive movements that are involved. However, there are very few studies on MSDs and rest breaks as a workplace intervention among kitchen workers. This study examined the relationship between insufficient rest breaks and increased MSD risk among Korean kitchen workers. Methods: Sociodemographic and occupational factors of 1,909 kitchen workers were collected from the 3rd-4th Korean Working Conditions Survey data. Five items on rest breaks at work were categorized into two groups, "sufficient" and "insufficient." The number of MSDs and work-related MSDs (WMSDs), an outcome variable, was obtained from the sum of MSDs/WMSDs in three anatomical sites (back, neck, and upper limb, lower limb). The association between rest breaks and MSDs was estimated using zeroinflated negative binomial analyses, with adjustments for age, education level, and weekly working hours, and the analyses were stratified by sex. Results: After adjustment, significant associations were found between insufficient rest breaks and an increased risk of MSDs (odds ratio [OR] 1.68 95% confidence interval [CI] 1.11-2.54) and WMSDs (OR 1.40 95% CI 1.01-1.96) among female kitchen workers. Insufficient rest breaks were significantly associated with MSDs in female kitchen workers in all three anatomical sites. Conclusion: This study emphasizes the need for rest breaks as a workplace intervention for preventing MSDs in kitchen workers. Further studies to reveal the causality of this relationship are required.

• 한국산학기술학회논문지
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• 제13권9호
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• pp.3999-4008
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• 2012

본 연구는 물리치료사의 직무에 따른 Work-Related Musculoskeletal Disorder(WMSD)s에 대한 증상을 파악하기 위하여 통증치료군(56명), 성인 운동치료군(53명), 소아 운동치료군(22명)을 대상으로 근골격계 증상조사표와 Rapid Upper Limb Assessment(RULA)를 사용하여 근골격계 증상 및 작업의 유해도를 알아보기 위해 실시하였다. 그 결과 통증치료군 69.6%, 성인 운동치료군 84.9%, 소아 운동치료군 81.8%, 평균 77.9%의 자각 증상 호소율을 보였다. RULA를 이용한 인간공학적 위험 평가에서 Final Wrist & Arm Score와 Final Score에서 성인 운동치료군이 단위 시간당 작업 부하량이 가장 많은 것으로 나타났으며 Action Level은 통증치료군이 평균 $3.0{\pm}0.9$, 성인 운동치료군은 $3.3{\pm}0.6$, 소아 운동치료군은 $3.2{\pm}0.8$로 성인 운동치료군에서 가장 높았다. 근골격계 증상에 영향을 미치는 요인 중 키, 가사 노동, 육체적 부담정도, 과거 사고가 통계적으로 유의하였다. 이에 따라 물리치료사의 WMSDs를 방지하기 위한 장비 및 교육시스템이 보급되어야 할 것으로 사료된다.