• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.56
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• pp.93-102
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• 2000

Today, the number of automated machine has rapidly increased in industrial workplaces. Nevertheless, workers are often required to handle materials manually. Technical information for using the revised NIOSH lifting equation to evaluate a variety of two - handed Manual Material Handling (MMH) tasks was investigated. The NIOSH suggested the Lifting Index that provides a relative estimate of the level of physical stress associated with a particular manual lifting task. To measure operator's workload in lifting task, Lifting Index Simulator(LIS) was developed based upon the revised NIOSH lifting equation in this study. The purpose of this study was to develop LIS and use the NIOSH lifting equation in our workplace.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.106-110
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• 1995

A local manufacturing companyin which low back pain(LBP) complaints were frequently reported was selected, and regularly perfomed lifting tasks were investigated using questionnaires and the 1991 NIOSH lifting guide. Among several processes of manufacture in the company, three processes-forming, heating and packing-were studied, where most of tasks were perfomed through manual materials handling (MMH). Questionnaire surveys showed that anthropometric data such as stature, weight and someatotype did not affect and weight of load influenced significantly the incidence of LBP, and workers who expwrienced LBP was older than the inexperienced. In addition, safety education conducted at the company was found to be ineffective in preventing LBP injuries. Lifting indexes(LI) was ranged from 0.86 to 17.0 with an average of 4.49, which revealed that tasks performing in the selected factory were in danger of LBP, and should be ertonomically redesigned. The critical factor reducing LI was found to be the horizontal component in all three processes, and most of weight of load was heavier than load constant(23kg) of the 1991 NIOSH lifting equation in heating process and packing.

• 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 the Ergonomics Society of Korea
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• v.14 no.1
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• pp.91-96
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• 1995

The purpose of this study was two-fold : (1) to investigate the difference between the lifting capacities based on three different ergonomic approaches; a) the biomechanical, b) the physiological, and c) the phsychophysicalo approach, and the 1991 revised NIOSH Equation, and (2) to develop a comprehensive model for deter- mining maximum weight of lift.

• Journal of Industrial Convergence
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• v.1 no.2
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• pp.17-31
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• 2003

Many risk factors with the onset of Low Back Pain(LBP) have been identified, however, lifting out of Manual Material Handling(MMH) was the most important factor to the LBP. Injuries due to lifting took account for 34.0%(227,291) out of the total overexertion in MMH(668,084). The weight, vertical location, twist angle, lifting frequency, and lifting posture were reviewed in this study. Technical information for using the revised lifting equation to evaluate a variety of two - handled manual material handling tasks was suggested. To measure worker's fatigue in lifting task, Lifting Index Simulator(LIS) was create under the revised NIOSH(National Institute for Occupational Safety and Health) lifting equation. For the implementation of the LIS, data was collected in A company manufactures various paints in Si-Wha industrial complex, Kyunggi-Do. The results of the Lifting Index(LI) were analyzed by MANOVA to find the relation with lifting variables collected. It was found that horizontal distance, vertical distance, travelling distance and frequency were significant at the 0.01 level and weight was significant at the 0.05 level. The purpose of this paper is to reduce the chronical low back pain for the manual material handlers.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.50-54
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• 1999

In the process of designing a wheel balancer an ergonomic evaluation model has shown that manual tire handling onthe machine was often the major problem, The root of the problem lay in the design of machine's shaft which is influenced by the opeative handling task. Several methods were reviewed for determining the correct shaft' sizes but the Revised NIOSH Equation and the Lifting Stress Calculator were found to be the only suitable models for this study. An application of these mathematical models has shoed that the shaft length and the shaft height were the most critical measurement By analyzing these conclusion s the correct shaft size parameters became clearly defined.

• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.3
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• pp.284-289
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• 2006

In 2003, Korean government made the 11 scopes of overburdened work[Ministry of Labor(MOL), Notification No. 2003-24] to prevent musculoskeletal disorders(MSDs). MOL Notification was established based on 'Washington Administrative Code 296-62-051, Ergonomics'. When initially investigating the contents, the labor unions and the specialists pointed out the possibility of devaluation on risk factors of MSDs. The present study aimed to compare the result of the NIOSH revised lifting equation(NLE) analysis with the MOL Notification(No.8, 9, 10) on manual lifting tasks. A study sample of 568 manual lifting tasks (automobile parts, foods, and tire manufacture) were evaluated for this study. All 502 tasks exceed lifting index(LI) of 1.0, but 276 tasks(55.0%) out of 502 tasks were evaluated non-over burdened work for musculoskeletal system by the MOL Notification. Particularly, 47 tasks(30.9%), in spite of exceeding LI of 3.0, were evaluated non-over burdened work. This study has shown the possibility of devaluation on risk factors of MSDs, when evaluated by MOL Notification. Therefore, it will be necessary to repeal or complement the scope of over-burdened work(MOL Notification) to prevent musculoskeletal disorders.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.2
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• pp.104-113
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• 2005

A variety of ergonomic assessment methods of lifting tasks known as a major cause of work-related lower back pain have been used. But there is a limited information in choosing the most appropriate assessment method for a particular job and in finding out strengths and weakness of the methods. The purpose of this study was to assess and compare the ergonomic risks of lifting tasks in a marine diesel engine production industry by three lifting ergonomic assessment tools widely used: the National Institute for Occupational Safety and Health(NIOSH) Revised Lifting Equation(NLE), the Washington Administrative Code 296-62-0517(WAC), and the Snook Tables. Lifting index(weight of load/Recommended Weight Limit) of NLE($LI_{NLE}$) was above 1 at 34 tasks(75.6%) of a total number of 45 lifting tasks. LI of WAC($LI_{WAC}$) was above 1 at 11 tasks(24.4 %). LI of Snook Table($LI_{Snook}$) was above 1 at 29 tasks(64.4%). Thus, LI was high in orders of $LI_{NLE}$ > $LI_{Snook}$ > $LI_{WAC}$. There were significantly high correlations among three Lls(p<0.01). The correlation coefficients between $LI_{NLE}$and the other three Lls($LI_{WAC}$ and $LI_{Snook}$) were r=0.93 and r=0.88, respectively. The linear regression equations were y = 0.444x + 0.11(r=0.93) between $LI_{NLE}$ and $LI_{WAC}$, y = 0.93x + 0.008(r=0.88) between LI(NLE) and $LI_{Snook}$. The LI values by WAC was significantly lower than those by the other tools. The compared features, strength and limitation among these tools were described in this paper.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.3
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• pp.239-247
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• 2008

Low back disorders (LBDs) have been the most common musculoskeletal problem in Korean workplaces. It affects many workers, and is associated with high costs to many companies as well as the individual, which can negatively influence even the quality of life of workers. The _evaluation of low back disorder risk associated with manual materials handling tasks can be performed using variety of ergonomic assessment tools such as National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (NLE), the Washington Administrative Code 296-62-0517 (WAC), the Snook Tables etc. But most of these tools provide limited information for choosing the most appropriate assessment method for a particular job and in finding out advantage and disadvantage of the methods, and few have been assessed for their predictive ability. The focus of this study was to _evaluate spinal loads in real time with lifting and pulling heavy cow leathers in variety of postures. Data for estimating mean trunk motions were collected as employees did their work at the job site, using the Lumbar Motion Monitor. Eight employees (2 males, 6 females) were selected in this study, in which the load weight and the vertical start and destination heights of the activity remained constant throughout the task. Variance components (three dimensional spaces) of mean trunk kinematic measures were estimated in a hierarchical design. They were used to compute velocity and acceleration of multiple employees performing the same task and to repetitive movements within a task. Therefore, a results of this study could be used as a quantitative, objective measure to design the workplace so that the risk of occupationally related low back disorder should be minimized.