• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.05a
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• pp.307-312
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• 1998

In forklift operations, awkward postures due to backward driving may put drivers to the risk of CTD or low back pain. In this research, 6 forklift drivers were surveyed with OWAS for objective posture evaluation and bodymaps for self-report evaluation. The backward driving happened more frequently than forward driving as expected, and, as work hours passed by, the drivers naturally tended to assume the easier work postures in inverse proportion to the frequency of the backward operations. According to the results of OWAS, 60 % of the work postures in the forklift operations belonged to the category II, III, and IV classified serious. Especially, in the backward driving, the postures with the neck twisted over $45^{\circ}$ occupied 82.4 %. In addition, discomfort on the neck, left shoulder, and low back was frequently reported in the self-reports.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.108-113
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• 2006

The Work-Related Musculoskeletal Disorders(WMSDs) have been an rising issue since the 1970s. So many manufacturing companies have been tried to improve the work environments for the control and the prevention of the WMSDs. Specific risk factors associated with WMSDs include repetitive motion, heavy lifting, forceful exertion, contact stress, vibration, awkward posture and rapid hand and wrist movement. But recently it has reported that besides working conditions, job stress is the important hazard causes which lead to WMSDs. This study investigates the relation between WMSDs and Job stress from 1426 workers in Heavy Industry. Job stress was evaluated by Karasek's model. Job stress was associated with job satisfaction. Job demand was associated with the WMSDs, but job control was not associated with the WMSDs. The results can be used to design the management program for the WMSDs and the job stress.

• Journal of the Korean Society of Safety
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• v.27 no.1
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• pp.111-116
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• 2012

Workers who work with his neck bent backward in the standing posture have often complained of their musculoskeletal stress. The objective of this study was to find how much stress there was for workers who worked with their neck bent backward. The subjective evaluation and electromyography(EMG) were used to check the level of the stress. It was found that all subjects felt extreme pain after working with the neck bent backward and alternating 1 minute work and 0.5 minute rest for 30 minutes. The EMG level(amplitude) of neck muscles increased 80 percent on the average and the center frequency of EMG shifted to the lower frequency level which indicated fatigue of neck muscles. Thus, the intervention of this musculoskeletal stress is strongly recommended.

• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.69-78
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• 2009

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 autoparts 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 RULA, OWAS 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.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.77-86
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• 2004

Observational methods to evaluate postural load have an intrinsic week point that is the problem of reliability in observing postures subjectively, although they have been widely used in assessing risk factors of work-related musculoskeletal disorders in the industry. In this study, observational reliability was discussed based on reviewing several previous studies. Practical guidelines was presented to reduce the observational errors when using video recording for the assessment of risk factors. In addition, previous studies on observational reliability were summarized and analyzed according to body parts to be observed, media for observation, objective measures, analysis, statistics, etc. It is expected that this basic study can be used to increase the applicability and accuracy of the observational methods.

• Journal of the Korea Safety Management & Science
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• v.6 no.4
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• pp.99-106
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• 2004

In developing criteria for establishing workstation reach limits, it is essential to select the appropriate anthropometric stereotype for solving a specific design problem. The most important factor for comfortable workstation is to eliminate trunk flexion from the neutral (upright) posture. A solution to this design can be developed using population stature and link length data. This paper provides a methodology for design of comfortable workstation using anthropometric stereotype. Application of this methodology can be utilized in various designs for work space including standing and sitting workplace. For the purpose of this study, the data are measured by some parts on body such as stature, arm length, wrist height, elbow height, and shoulder hight. The samples for this study are randomly chosen from university students in Seoul and Kangnung during sixteen months (2003.3-2004.6).

• Journal of the Korea Safety Management & Science
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• v.9 no.2
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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.

• Journal of the Korean Society of Safety
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• v.16 no.2
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• pp.117-120
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• 2001

Low back pain has been known as the most frequent musuculoskeletal disorders in modern industrial society and cost by low back pain is increasing mon and more. The asymmetric lifting has been identified as a major risk factor of low back pain. In this study, the muscle activity and muscle exertion level during asymmetric load handling (without trunk flexion) was estimated. The results of normalized MVC measurement were decreased about 16％, 24％, 34％ respectively as the asymmetric angle was $30^{\circ}$, $60^{\circ}$, $90^{\circ}$. From the results of EMG measurement contralateral muscles were more active than ipsilateral muscles. RMSEMG values of right erector spinae muscles were decreased as the work posture went to 90$^{\circ}$ and those of left erector spinae muscles were increased until the asymmetric angle was 40$^{\circ}$ but decreased continually over 40$^{\circ}$. And for seven of subjects, activities of left and right latissimus dorsi muscles were maintained constantly, while for remainer, those were irregular.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.41-46
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• 2014

The design of a 7 degree of freedom motion capture device(MCD) has been presented. The newly designed MCD overcomes the shortcomings of the existing CADEN-7 exoskeleton robot by implementing various ergonomic design. To improve ease of operation, light-weight high-strength materials such as carbon pipes and engineering plastics were used to reduce weight of the MCD and arm-length adjustment mechanism was also added. The MCD showed consistent measurement results in designed experiments involving change of arm posture from nominal configuration to either elbow-side or arm-front configurations. Furthermore, captured motion in more natural tennis swing appeared to agree well with visual observations made.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.105-110
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• 2008

This study focused on the decreased effect of the work load on using the lower extremity supporter in kneeling posture. Fatigue measures included subjective discomfort ratings through the use of the Borg's CR-10 scale based parameters. The resting period and work method were considered as independent variables. The break time conditions are grouped into 10 seconds after work for 1 min and not exist break time. The method of work conditions are divided into four types. There are kneeling with the lower extremity supporter, kneeling with the knee protector, just kneeling and squatting. The result of the ANOVA of the shift value of subjective discomfort showed the followings: 1) There were differences as regards to the method of the work, the break time and the part of body($p{\leq}0.05$). 2) The lower extremity supporter showed the least subjective discomfort in other part of body except the upper leg.