• International Journal of Clinical Preventive Dentistry
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• 제14권4호
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• pp.235-240
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• 2018

Objective: The purpose of this study is to examine about dental hygienists' myofascial pain syndrome, lower back pain, carpal tunnel syndrome (CTS), medial and lateral epicondylitis, hand-arm vibration syndrom and work-related musculoskeletal syndrome (WMSD) experience and hygienists' posture, motion. Methods: The self-administered questionnaire was surveyed from June 1 to September 30 of 2018 targeting 280 dental hygienists in Gyeongnam province and 266 dental hygienists' answers were analyzed. Results: The average daily working hours of a dental hygienist was more than eight hours 59.0%, with an average of 33 patients per day. The average number of patients who receive treatment for more than 30 minutes is 15. The angle of motion of the subjective evaluation was above 60%. Medical position and form of movement were more than 50% above the standard level. Symptoms of posture and motion that cause WMSD were hand-arm vibration syndrome 68.1%, myofascial pain syndrome 58.6%, lower back pain 51.1%, CTS 50.4% in order. Experience WMSD related symptoms which dental hygienists experience were myofascial pain syndrome 92.9%, CTS 57.9%, lower back pain 56.4%, medial and lateral epicondylitis 37.2%, hand-arm vibration syndrome 24.4%. Conclusion: The above results showed the posture and motion of dental hygienists and were found that the experience rate which dental hygienists experience WMSD of myofascial pain syndrome, Lower back pain, and CTS was significantly more than 56%.

• 한국산업보건학회지
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• 제15권3호
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• pp.250-260
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• 2005

This study was designed to find the symptom prevalence rates of musculoskeletal disorders and the risk factors of musculoskeletal disorders among selected hair dressers. Methods; The survey were conducted from July 1 to 30, 2004 for 459 hair dressers working in Seoul and Gwangju using self-administration questionnaire. The risk factors on musculoskeletal disorders have analysed by multiple linear regression analysis. The results of this study are summarized as follows: The experience rate of musculoskeletal disorders symptom in the last one year was 56.4%. The experience rates of each body parts were 36.4% on the shoulders, 30.5% on the legs and the feet, 28.5% on the low back, 27.0% on the hand and the fingers, 23.3% on the neck and 17.0% on the arms and the elbows. The prevalence rate of musculoskeletal disorders symptom in the last one week was 40.5%, those of each body parts were 24.0% on the legs and the feet, 21.4% on the shoulders, 20.7% on the low back, 15.7% on the hand and the wrists, 15.0% on the neck, 9.4% on the arms. The risk factors on musculoskeletal disorders were working posture(${\beta}=0.32$), perceived stress(${\beta}=0.19$), working period(${\beta}=0.16$), standing working over 10 hour(${\beta}=0.16$), hard working(${\beta}=0.11$). The adjusted determinant coefficient($R^2$) of this regression model was 0.267. Based on the results, in order to prevent musculoskeletal disorders of hair dressers, working posture shall be improved and leisure opportunities to relieve stress, and health management program shall be provided.

• 대한인간공학회지
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• 제32권5호
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• pp.469-474
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• 2013

Objective: The purpose of this study was to analyze the risk factors of MSDs for the types of office work. Background: Physical risk factors of VDT(Video Display Terminal) associated with shoulder and neck musculoskeletal disorders(MSDs) include static work postures and workstation status. Method: In this study, office work was divided into data search, data entry and design work(drawings, etc.), and then we were surveyed 7 major work places which was included these works. We recorded working postures and obtained still images, depending on the types of office work. Then, RULA(Rapid Upper Limb Assessment) and ROSA(Rapid Office Strain Assessment) were used to analysis the risk factors. Results: The results of RULA showed that design work was under risk levels and required change, but ROSA showed that data entry and design work were high risk. The RULA is to evaluate the level of risk factors based on the working posture; on the other hand, the ROSA is to consider the use of peripheral, same as chair, keyboard/mouse, monitor and computer workstations. Conclusion: Conclusions of this study, the office work is necessary to identify the risk factors caused by the use of peripheral, as well as working posture.

• 대한안전경영과학회지
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• 제16권1호
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• pp.119-127
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• 2014

This study tried to develop a basis for quantitative index of working postures associated with WMSDs (Work-related Musculoskeletal Disorders) that could overcome realistic restriction during application of typical checklists for WMSDs evaluation. The baseline data(for a total of 603 jbs) for this study was obtained from automobile manufacturing company. Specifically, data for back posture was analyzed in this study to have a better and more objective method in terms of job relevance than typical methods such as OWAS, RULA, and REBA. Major statistical tools were clustering, logistic regression and so on. The main results in this study could be summarized as follows; 1) The relationship between working posture and WMSDs symptom at back was statistically significant based on the results from logistic regression, 2) Based on clustering analysis, three levels for WMSDs risk at back were produced for flexion as follows: low risk(< $18.5^{\circ}$), medium risk($18.5^{\circ}{\sim}36.0^{\circ}$), high risk(> $36.0^{\circ}$), 3) The sensitivities on risk levels of back flexion was 93.8% while the specificities on risk levels of back flexion was 99.1%. The results showed that the data associated with back postures in this study could provide a good basis for job evaluation of WMSDs at back. Specifically, this evaluation methodology was different from the methods usually used at WMSDs study since it tried to be based on direct job relevance from real working situation. Further evaluation for other body parts as well as back would provide more stability and reliability in WMSDs evaluation study.

• 대한안전경영과학회지
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• 제10권4호
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• pp.21-30
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• 2008

The psychosocial stress and musculoskeletal disorders(MSDs) have been one of major health problems for hospital workers. This study tried to understand the relationship between symptoms associated with MSDs and risk factors such as working posture, job stress, psychosocial stress and fatigue. A total number of 655 hospital workers participated in this study. Specifically, REBA was applied for evaluating working posture and a checklist prepared by KOSHA(Korean Occupational Safety and Health Agency) was used for symptom survey. A questionnaire from KOSHA was also used for collecting data associated with job stress, psychosocial stress and fatigue. All these data were formulated and modeled by path analysis which was one of major statistical tools in this study. Specifically, path analysis for the data we collected came up with several major findings. The risk scores from working posture based on REBA had indirect effects via fatigue factor(MFS) as well as direct effects on symptoms. The factors associated with job stress (KOSS) and psychosocial stress(PWI-SF) had significant effects on symptoms. Specifically, indirect effect of job stress factors via fatigue factors(MFS) had bigger than that of direct effect of job stress on symptom.

• 한국산림과학회지
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• 제90권3호
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• pp.388-397
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• 2001

작업환경의 개선이 불가능한 임업에 있어서 올바른 작업자세는 불필요한 체력의 낭비 및 누적된 특정부위에서 피로로 유발되는 상해발생 예방, 체력 저하로 인한 주의력 감소로 야기되는 휴먼에러 예방 등의 직접적인 효과를 가져 올 수 있을 것으로 판단된다. 이에 본 연구는 OWAS분석기법을 이용하여 체인톱을 이용한 간벌작업, 체인톱을 이용한 피해목벌채작업, 손톱을 이용한 임내정리작업, 낫을 이용한 덩굴제거작업, 고지절단톱을 이용한 가지치기작업, 낫을 이용한 어린나무가꾸기작업에 대하여 작업자세분석을 실시하였다. 주요 작업 중, 체인톱과 낫을 이용한 작업에서 근골격계에 약간의 해를 끼침으로 가까운 시일 내에 작업자세의 교정이 필요한 수준(수준 III)의 코드비율과 근골격계에 매우 심각한 해를 끼침으로 즉각적인 작업자세의 교정을 필요로 하는 수준(수준 IV)의 코드비율이 높게 조사되었다. 체인톱을 이용한 벌목작업에서 미숙련자와 숙련자의 작업자세를 비교해 본 결과, 수준 IV의 경우 중간 수준의 숙련자가 5.1%로 14.1%의 미숙련자 보다 낮은 것으로 조사되었다.

• 한국안전학회지
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• 제26권5호
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• pp.81-88
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• 2011

The goal of this study was to determine whether food industry workers are exposed to musculoskeletal loads due to the work time, frequency, awkward postures and inappropriate workspace design. Three catering workers were evaluated based on job analysis and posture analysis. The results showed that the four most time-consuming tasks were arranging(17%), cooking(16%), handling before cooking(15%) and cutting(15%), and the four most frequent tasks were arranging(21%), cooking(18%), handling after cooking(16%) and handling before cooking(13%). The most common posture was a standing posture(73%) with neutral back(73%), and bent head(50%), left lower arm(71%), right lower arm(78%) and right hand(60%). The comparative analysis of subtasks for the risk levels of musculoskeletal disorders was conducted using the work time, frequency and cumulative time of the postures. The 'displaying' and 'handling after cooking' showed higher risk levels than other subtasks. In addition, the height and length of the tables were evaluated to be inadequate for the workers. It can be concluded that the working environments for catering workers of restaurants should be improved due to the high cumulative time of awkward postures of upper extremities.

• 대한인간공학회지
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• 제30권5호
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• pp.637-644
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• 2011

Objective & Background: When applying various evaluation tools that analyze work posture risk through observation, accurate measurement of body flexion angle is very important. Method: This study investigated differences and appropriateness of 5 different existing reference points commonly used in the analysis of the work posture. Twenty five ergonomist and trained professionals were participated in this study. A Same flexion angle was utilized for the evaluation of risk assessment of musculoskeletal disorders using five different reference points to investigate the degree of difference between them. To investigate how different the observers' preferred flexion angle measuring methods were compared to the ISO 11226 Reference Posture, a virtual body model was constructed using the Poser 6.0 program. Six types of body flexion postures were constructed, and since neck flexion differs according to body angle, five types of neck flexion postures were constructed with the trunk bending $20^{\circ}$ forward, making up a total of 30 virtual flexion postures. Results: Results showed that the observers used personally preferred reference points instead of reference points recommend in the evaluation tools. Also the results revealed the their seems to be 6 types of flexion angle for the trunk and 11 types of measurement methods for the neck flexion angle in the form of personally preferred reference points. The results showed that a mean difference of $14^{\circ}$($4{\sim}23^{\circ}$) occurred in the trunk, and a mean difference of $20^{\circ}$($-8{\sim}51^{\circ}$) occurred in the neck. To increase accuracy when using the 5 evaluation tools in combination, the ISO 11226 standards, observers' preferred flexion posture standards, and common flexion posture standards of the evaluation tools were compared with the reference points of the 5 evaluation tools. Results showed considerable variance in angle difference for each evaluation tool. Conclusion: According to the results of this study, considering the angle difference between the flexion angle reference points of the evaluation tool and the reference points selected by the observers, it is concluded that instead of personally preferred reference points, the standardized reference points to enhance the accuracy and the objectivity. Application: The result of this study can be used as reference guide to develop the standardized reference point in the future.

• 대한인간공학회지
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• 제30권6호
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• pp.695-703
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• 2011

Objective: This study was to investigate the effects of coordinated upper-limb body postures on the subjective discomfort rating, heart rate, and muscle activities. Background: Although generally many checklists such as OWAS, RULA, and REBA were applied to evaluate various body postures, the body postures were might be overestimated or underestimated because each body part(i.e., back, shoulder, and elbow etc.) was evaluated separately, and then added all rates of individual body parts to assess an overall risk level for the body posture in these methodologies. Methods: A total of 20 participants maintained 14 postures which were combinations of back, shoulder, and elbow flexion angles and then muscle activities, subjective discomfort, and heart rates were collected every three minute during a sustained 15 minute and 0.5kg weight holding task. Four muscle groups were investigated: erector spine, anterior deltoid, upper trapezius, triceps brachii. Results: Results showed that subjective discomfort was the lowest when the angle of back and shoulder were both $0^{\circ}s$, while the body posture with $45^{\circ}$ of back angle and $45^{\circ}$ shoulder angle was rated as the most subjective discomfort posture. In general, the subjective discomfort ratings increased as back and shoulder flexion angles increased. It was noted that, however, the subjective discomfort of body posture with a $45^{\circ}$ back angle and $45^{\circ}$ shoulder flexion angle was lower than that of body posture with a $0^{\circ}$ back and $45^{\circ}$ shoulder flexion angle. The research findings of heart rates and muscle activities showed similar results for the analyses of subjective discomfort ratings. Conclusions: The possible limitations of the current ergonomics evaluation techniques which assessing a body posture with summing all body part score after individually analyzed in this study. Based on the analyses of subjective discomfort, heart rate, and muscle activities, it was recommended that a use of effects of coordinated upper-limb body postures would be considered when one evaluates work-load for various working postures. Application: These findings can be used for developing a more accurate assessment checklist for working posture as well as preventing musculoskeletal disorders of workers in workplaces.

• 대한안전경영과학회지
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• 제9권2호
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• pp.33-48
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• 2007

The goal of this study is to propose the effective method of investigating the injurious factors and making improved plans that prevents the workers against musculoskeletal disorders at an autopart company and the same business field with similar working conditions and process. A questionnaire were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an ergonomic assessment method such as QEC, RULA, S.I were performed to find out harmful factors of workplace and working posture. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. It can be concluded that the method and process described in this paper could be helpful for diagnosing the musculoskeletal disorders and making improvement plans to the autopart company and the same business field with similar working conditions and process.