Lifting Index Research Articles

Lifted flame property and interchangeability of natural gas on partially premixed gas burners

The relationship between lifted flames and burner head temperature of partially premixed gas burners supplied by various natural gas sources was investigated, and the application of AGA(American Gas Association) lifting limit for Chinese domestic gas burners was studied. Results showed that lifted flames became more seriously with the burner head temperature decreasing, also with the increase of lift height of flames, it would lead to reduce the burner head temperature, eventually the burner head would reach the thermal equilibrium state which maintained stable flames and temperature. The lifting limit curve of partially premixed gas burners was only one under the same gas source, and it only depended on the burner structures and gas source characteristics, but nothing to do with the burner head temperature. The gas source with lower Wobbe index and calorific value made the burner appearing lifted flame more easily. Comparing with the experiment results and AGA lifting index prediction, it suggested that the limits of AGA lifting index IL≤ 1.10 should be change into IL≤ 1.05 using in China.

The lean ergonomics in green design of crude palm oil plant

Ergonomics can help manufacturing and industrial engineersmaximum work output without physical harm to workers.Physiology, biomechanics, anthropometrics, and allocation are the areas of ergonomics most useful to manufacturing in apllying the concept of Lean and Green in manufacturing. These systems require efficient production and low use of resources such as energy and material. Its philosophy encourage worker to look at waste. This concept is applied in one of national plant of Crude Palm Oil (CPO) that located in North Sumatera. The problem found in the company are the working posture and excessive workload of the workers. These conditions are affects to the their job performance. The study was carried out by evaluated the worker body position using the Work Posture Assesment (WPA) and Biomechanics method. The WPA results shows the operator’s working position was mostly bent more than 30 degrees. This indicates that almost all workers are felt musculoskeletal disorders during work hours. While the biomechanics analysis found the significant relation between the values of Recommended Weight Limit (RWL) and Lifting Index (LI) which the increase of RWL value will decrease the LI value. This indicated that the recommended load for a worker under certain circumstances affects the appointment made so as not to contain the risk of spinal injury. In fact these condition are due to in-efficiency in production which can be maintaned the green design of CPO plant by improving the existing work.

Ergonomic risk assessment of manual material handling at an automotive manufacturing company

This study investigates ergonomic risks faced by manual material handling (MMH) workers performing repetitive loads carrying, holding, lifting, lowering, pushing and pulling activities. A total of 11 MMH workers was recruited to participate in the study. Methods used to collect data were Modified Nordic Questionnaire (MNQ), Rapid Entire Body Assessment (REBA) and NIOSH Lifting Equation. MNQ result showed the MMH workers’ body parts that suffered pain are shoulders (63.6%), upper back (54.5%) and lower back (45.4%). The movements, which recorded high REBA score (i.e. 9) are twisting, lowering and lifting, which is considered as high risk. Based on NIOSH Lifting Equation, the value of RWL for MMH tasks is 15.82 and the lifting index (LI) is 0.73. The recommended control measures to be implemented in Company X include to limit the working time, administrative control, training, and reduce the weight of the load carried and lifted by the MMH workers.

Analisis Manual Material Handling Pada Pekerja Borongan Di PT. JC dengan Metode NBM dan RWL

PT. JC is a company that uses means of transporting goods to the manual process, or so-called Manual Materials Handling (MMH) is done by workers in the Department of Warehouse. In addition to the process of moving goods by using aids such as forklifts manual removal is still needed in this company because it has advantages compared to using the tool for material removal manually can be done in a limited space.
 
 In the process of manual material handling led to several complaints that arise and can be analyzed using a Nordic body map (NBM). The use of nordic body map is an appropriate method to use because by analyzing the map of the body aimed at any part of the body feels pain.
 
 Besides complaints can also be known value Recomended Weight Limit (RWL) as recommended by NIOSH (National Institute of Occupational Safety and Health) on estimates possibility of stretching further to the value of Lifting Index (LI) aims to determine the estimated value relative to the voltage level of physical processes manual material handling. From manual material handling processes that cause the symptoms of musculoskeletal disorder completion technically be done to minimize the effects on workers.

The ergonomics body posture on repetitive and heavy lifting activities of workers in aerospace manufacturing warehouse

Warehouse is an important entity in manufacturing organizations. It usually involves working activities that relate ergonomics risk factors including repetitive and heavy lifting activities. Aerospace manufacturing workers are prone of having musculoskeletal disorder (MSD) problems because of the manual handling activities. From the questionnaires is states that the workers may have experience discomforts experience during manual handling work. Thus, the objectives of this study are; to investigate the body posture and analyze the level of discomfort for body posture of the workers while performing the repetitive and heavy lifting activities that cause MSD problems and to suggest proper body posture and alternatives to reduce the MSD related problems. Methodology of this study involves interviews, questionnaires distribution, anthropometry measurements, RULA (Right Upper Limb Assessment) assessment sheet and CATIA V5 RULA analysis, NIOSH lifting index (LI) and recommended weight limit (RWL). Ten workers are selected for pilot study and as for anthropometry measurement all workers in the warehouse department were involved. From the first pilot study, the RULA assessment score in CATIA V5 shows the highest score which is 7 for all postures and results after improvement of working posture is very low hence, detecting weight of the material handling is not in recommendation. To reduce the risk of MSD through the improvisation of working posture, the weight limit is also calculated in order to have a RWL for each worker. Therefore, proposing a guideline for the aerospace workers involved with repetitive movement and excessive lifting will help in reducing the risk of getting MSD.

Mechanical lifting energy consumption in work activities designed by means of the "revised NIOSH lifting equation".

The aims of the present work were: to calculate lifting energy consumption (LEC) in work activities designed to have a growing lifting index (LI) by means of revised NIOSH lifting equation; to evaluate the relationship between LEC and forces at the L5-S1 joint. The kinematic and kinetic data of 20 workers were recorded during the execution of lifting tasks in three conditions. We computed kinetic, potential and mechanical energy and the corresponding LEC by considering three different centers of mass of: 1) the load (CoML); 2) the multi-segment upper body model and load together (CoMUpp+L); 3) the whole body and load together (CoMTot). We also estimated compression and shear forces. Results shows that LEC calculated for CoMUpp+L and CoMTot grew significantly with the LI and that all the lifting condition pairs are discriminated. The correlation analysis highlighted a relationship between LEC and forces that determine injuries at the L5-S1 joint.

PERBAIKAN FASILITAS PEMINDAHAN BAG PAKAN UDANG DI DEPARTEMEN PACKAGING GUNA MENGURANGI RESIKO CEDERA TULANG BELAKANG

Manual Materials Handling (MMH) activities still widely used in a job. This is because in this activity has a high flexibility, inexpensive, and easy to apply. However, these activities also constitute a risk when applied to the inadequate environment, less support of tool, and bad posture of work. Therefore, measurement of safety limit in doing the job by using a calculation based on the equation of NIOSH Lifting Index. The case study at PT. Central protein Prima Surabaya is the removal of shrimp feed bag that still use manual way. Acquisition of STRWL calculation results obtained for the removal of shrimp feed bag stacks 1, 2, 3, 4, 5, 6, and 7 from 5,003 Kg to 67,41 Kg. Actual load which worker must lifted in this case study on a pile of 1 to 7 is 25 kg. Load is lifted for the removal of shrimp feed bag bigger than STRWLmake it not feasible. CLI obtained in shrimp feed bag removal activity is 6.041 which value exceeds 3. Therefore CLI in this case study may create a risk of spinal cord injuries and to do their job changes. By measuring the changes in safety limits and do the work, expected reduced risk of injury to workers. After measuring the safe limit for the removal of bag obtained load is lifted workers have the risk of spinal injury, so it is given recommendations for improvement is by doing a redesign on a conveyor in the form of additional elevation (vertical) 57 cm at the end of the conveyor, as well as shortening the horizontal distance between the worker's body with a bag of shrimp feed time of transfer. With these recommendations obtained a decrease CLI becomes 1.795, which means that the risk of injury is between 1 <CLI ≤ 3 and can be reduced.

The Adequacy of NIOSH Equation to to Determine the Rate of Stresses Exerted on the Back Based on Compressive Force Estimation

Background: Manual handling may cause workers to deal with various risk factors. Workers performing such tasks repeatedly for a long time are more prone to bodily injuries and physical problems such as back pain. Objectives: The current study aimed to assess the compressive loads estimation and analysis of forces exerted on the workers’ back in manual load lifting tasks using the national institute for occupational safety and health (NIOSH) equation and compare them with the recommended weight limit (RWL). Methods: It was a cross-sectional study in a laboratory setting on 15 healthy male workers in 2015. The participants were required to randomly perform 25 tasks with four iterations. The lifting index (LI) was calculated by NIOSH equation in simple tasks and compressive loads on the low back (L4/L5) for each task were calculated using the 3DSSPP. Data were analyzed using SPSS version 16. Results: The results showed that the highest compressive force exerted on the back was equal to 4002 N and the lowest force 1425 N. Moreover, 76% of the tasks were reported to have the highest compressive force greater than the recommended limit; 72% of the tasks had an LI 1 - 3 and 28% of them had an LI less than 1. There was a weak direct correlation between compressive force and RWL. Conclusions: The NIOSH equation and compressive force estimation function were partially similar to identify high-risk tasks, however, by the compressive force estimation, biomechanical analysis of tasks can be done better since it is quantitative and can determine the exact amount of forces exerted on the back.

Primary air ratio change and gas interchangeability index correct for domestic gas cooker burning multi-source natural gases

In this paper, the influences of burner head temperature and gas properties on primary air ratio change of domestic gas cooker were studied, when natural gases interchange. Then though experimental test, the equation of AGA Lifting Index was modified and its interchangeability limits for Chinese natural gas interchangeability prediction was redefined. From results, when natural gases interchange, the original calculation equation of primary air ratio change should be corrected by temperature. The temperature correction coefficient m values1.1, when poor gas substitutes rich gas. As well as m values 0.9 when rich gas substitutes poor gas. And m values 1.0 when similar quality gases interchange. No flash-back and yellow tip were observed for all 17 domestic gas cookers under 11 test natural gases. Unfortunately, there were about half substitute natural gases appearing lifting, but all these gases were in the limit of AGA Lifting Index. Hence it verified that AGA Lifting Index IL can't be totally suitable when it's used to predict Lifting for Chinese natural gas interchangeability. According to natural gas interchangeability experiment on Chinese domestic gas cookers, it corrected the interchangeable limit of AGA Lifting Index IL as follows: total interchangeable, IL ≤ 1.09; interchangeable, 1.09＜IL＜1.13; un-interchangeable, IL ≥ 1.13.

Variable Lifting Index for Manual-Lifting Risk Assessment

The aim of this study was to evaluate the efficacy of the new Variable Lifting Index (VLI) method, theoretically based on the Revised National Institute for Occupational Safety and Health [NIOSH] Lifting Equation (RNLE), in predicting the risk of acute low-back pain (LBP) in the past 12 months. A new risk variable termed the VLI for assessing variable manual lifting has been developed, but there has been no epidemiological study that evaluates the relationship between the VLI and LBP. A sample of 3,402 study participants from 16 companies in different industrial sectors was analyzed. Of the participants, 2,374 were in the risk exposure group involving manual materials handling (MMH), and 1,028 were in the control group without MMH. The VLI was calculated for each participant in the exposure group using a systematic approach. LBP information was collected by occupational physicians at the study sites. The risk of acute LBP was estimated by calculating the odds ratio (OR) between levels of the risk exposure and the control group using a logistic regression analysis. Both crude and adjusted ORs for body mass index, gender, and age were analyzed. Both crude and adjusted ORs showed a dose-response relationship. As the levels of VLI increased, the risk of LBP increased. This risk relationship existed when VLI was greater than 1. The VLI method can be used to assess the risk of acute LBP, although further studies are needed to confirm the outcome and to define better VLI categories.

The Cumulative Lifting Index (CULI) for the Revised NIOSH Lifting Equation: Quantifying Risk for Workers With Job Rotation.

The objectives were to: (a) develop a continuous frequency multiplier (FM) for the Revised NIOSH Lifting Equation (RNLE) as a function of lifting frequency and duration of a lifting task, and (b) describe the Cumulative Lifting Index (CULI), a methodology for estimating physical exposure to workers with job rotation. The existing FM for the RNLE (FME) does not differentiate between task duration >2 hr and <8 hr, which makes quantifying physical exposure to workers with job rotation difficult and presents challenges to job designers. Using the existing FMs for 1, 2, and 8 hr of task durations, we developed a continuous FM (FMP) that extends to 12 hr per day. We simulated 157,500 jobs consisting of two tasks each and, using different combinations of Frequency Independent Lifting Index, lifting frequency and duration of lifting. Biomechanical stresses were estimated using the CULI, time-weighted average (TWA), and peak exposure. The median difference between FME and FMP was ±1% (range: 0%-15%). Compared to CULI, TWA underestimated risk of low-back pain (LBP) for 18% to 30% of jobs, and peak exposure for an assumed 8-hr work shift overestimated risk of LBP for 20% to 25% of jobs. Peak task exposure showed 90% agreement with CULI but ignored one of two tasks. The CULI partially addressed the underestimation of physical exposure using the TWA approach and overestimation of exposure using the peak-exposure approach. The proposed FM and CULI may provide more accurate physical exposure estimates, and therefore estimated risk of LBP, for workers with job rotation.

Evaluation of the Impact of the Revised National Institute for Occupational Safety and Health Lifting Equation.

The objective of this article is to evaluate the impact of the Revised National Institute for Occupational Safety and Health Lifting Equation (RNLE). The RNLE has been used extensively as a risk assessment method for prevention of low back pain (LBP). However, the impact of the RNLE has not been documented. A systematic review of the literature on the RNLE was conducted. The review consisted of three parts: characterization of the RNLE publications, assessment of the impact of the RNLE, and evaluation of the influences of the RNLE on ergonomic standards. The literature for assessing the impact was categorized into four research areas: methodology, laboratory, field, and risk assessment studies using the Lifting Index (LI) or Composite LI (CLI), both of which are the products of the RNLE. The impact of the RNLE has been both widespread and influential. We found 24 studies that examined the criteria used to define lifting capacity used by the RNLE, 28 studies that compared risk assessment methods for identifying LBP, 23 studies that found the RNLE useful in identifying the risk of LBP with different work populations, and 13 studies on the relationship between LI/CLI and LBP outcomes. We also found evidence on the adoption of the RNLE as an ergonomic standard for use by various local, state, and international entities. The review found 13 studies that link LI/CLI to adverse LBP outcomes. These studies showed a positive relationship between LI/CLI metrics and the severity of LBP outcomes.

Ergonomic Assessment for DHM Simulations Facilitated by Sensor Data

The digital factory with its innovative tools is experiencing an increasing importance, not only in experimental but also productive domains. One of these tools is the digital human model (DHM). In the field of production, the focus of using DHMs lies in the planning and evaluation of processes and products in terms of plausibility, productivity and ergonomics.Up to now, ergonomic assessment within DHM simulations have been mostly limited to static evaluations of reachability and postures.INTERACT is a running R&D project, working on the main weak points of DHM software tools. The industry-driven requirements are mainly the reduction of input effort, the increase of movement quality and a quick and intuitive way to create simulation variations in a workshop environment.The utilization of sensor data to create high quality simulations is another point of development.Next to the addressed improvement in productivity and plausibility, these latest advancements also enable automatic ergonomic assessments, including process oriented standards like EAWS, OCRA and NIOSH lifting index. The inclusion of these standards will allow a more holistic ergonomic assessment and therewith expand the fields of application in the industrial environment.This paper will give an insight in the latest developments and the performance of current implementations of automatic ergonomic assessment within digital human models.

Variable Lifting Index (VLI): A New Method for Evaluating Variable Lifting Tasks.

Objective:We seek to develop a new approach for analyzing the physical demands of highly variable lifting tasks through an adaptation of the Revised NIOSH (National Institute for Occupational Safety and Health) Lifting Equation (RNLE) into a Variable Lifting Index (VLI).Background:There are many jobs that contain individual lifts that vary from lift to lift due to the task requirements. The NIOSH Lifting Equation is not suitable in its present form to analyze variable lifting tasks.Method:In extending the prior work on the VLI, two procedures are presented to allow users to analyze variable lifting tasks. One approach involves the sampling of lifting tasks performed by a worker over a shift and the calculation of the Frequency Independent Lift Index (FILI) for each sampled lift and the aggregation of the FILI values into six categories. The Composite Lift Index (CLI) equation is used with lifting index (LI) category frequency data to calculate the VLI. The second approach employs a detailed systematic collection of lifting task data from production and/or organizational sources. The data are organized into simplified task parameter categories and further aggregated into six FILI categories, which also use the CLI equation to calculate the VLI.Results:The two procedures will allow practitioners to systematically employ the VLI method to a variety of work situations where highly variable lifting tasks are performed.Conclusions:The scientific basis for the VLI procedure is similar to that for the CLI originally presented by NIOSH; however, the VLI method remains to be validated.Application:The VLI method allows an analyst to assess highly variable manual lifting jobs in which the task characteristics vary from lift to lift during a shift.

The Application of NIOSH Lifting Equation to Prevent Musculoskeletal Disorder Risks

The objective of the study was to reduce musculoskeletal disorder risks by applying the NIOSH lifting equation variables include the horizontal location, the vertical location, the vertical travel distance, the asymmetric, the lifting frequency and the coupling classification. The 17 specific samples from 4W and ZECP division were selected by the weight of box 15.4 - 28.7 pounds. The standardized Nordic questionnaire for the analysis of musculoskeletal symptoms with pain scale from 0 (no pain) to 10 (worst pain) was used to self-report feeling. The ergonomics redesigns trained for the workers included: 1) brought the load closer to the worker by training; 2) raised the height of objects placed to reduce the vertical distance between the origin and destination of the lift; and 3) moved the origin and destination of lift closer together to reduce the angel twist. The new procedures were trained to all participated workers. The result found that the lifting index was safer (

Association between lifting and use of medication for low back pain: results from the Backworks Prospective Cohort Study.

To evaluate relationships between lifting and lowering of loads and risk of low back pain resulting in medication use (M-LBP). At baseline, worker demographics, psychosocial factors, hobbies, LBP history, and lifting and lowering (quantified using the Revised NIOSH Lifting Equation) were assessed. A cohort of 258 incident-eligible workers was followed up for 4.5 years to determine new M-LBP cases and changes in lifting/lowering requirements. Proportional hazards regression with time-varying covariates was used to model associations. Factors predicting M-LBP included peak lifting index (PLI) and composite lifting index (PCLI), LBP history, anxiety, and housework. In adjusted models, PLI and PCLI showed exposure-response relationships with peak hazard ratios of 3.8 and 4.3, respectively (P ≤ 0.02). Lifting of loads is associated with increased risk of M-LBP. The PLI and PCLI are useful metrics for estimating the risk of M-LBP from lifting.

0319 Biomechanical Comparison of Lumbar Risk Assessment in Manual Material Handling Work

ObjectivesIn this study, lifting index (LI) by NIOSH lifting equation (NLE) and biomechanical load by lumbar motion monitor (LMM) were determined to assess low-back disorder (LBD) risk associated with manual...

Efficacy of the Revised NIOSH Lifting Equation to Predict Risk of Low-Back Pain Associated With Manual Lifting

The objective was to evaluate the efficacy of the Revised National Institute for Occupational Safety and Health (NIOSH) lifting equation (RNLE) to predict risk of low-back pain (LBP). In 1993, NIOSH published the RNLE as a risk assessment method for LBP associated with manual lifting. To date, there has been little research evaluating the RNLE as a predictor of the risk of LBP using a prospective design. A total of 78 healthy industrial workers' baseline LBP risk exposures and self-reported LBP at one-year follow-up were investigated. The composite lifting index (CLI), the outcome measure of the RNLE for analyzing multiple lifting tasks, was used as the main risk predictor. The risk was estimated using the mean and maximum CLI variables at baseline and self-reported LBP during the follow-up. Odds ratios (ORs) were calculated using a logistic regression analysis adjusted for covariates that included personal factors, physical activities outside of work, job factors, and work-related psychosocial characteristics. The one-year self-reported LBP incidence was 32.1%. After controlling for history of prior LBP, supervisory support, and job strain, the categorical mean and maximum CLI above 2 had a significant relationship (OR = 5.1-6.5) with self-reported LBP, as compared with the CLI below or equal to I. The correlation between the continuous CLI variables and LBP was unclear. The CLI > 2 threshold may be useful for predicting self-reported LBP. Research with a larger sample size is needed to clarify the exposure-response relationship between the CLI and LBP.

Benefit of Adjustability When Depalletizing

Manual material handling is very prevalent in warehousing and large home improvement stores. Product is often shipped on pallets and then loaded to carts or pallet jacks. The objective of the current study was to evaluate two potential interventions: an adjustable pallet carousel and adjustable cart, using the NIOSH lifting index. Thirteen experienced males completed de-palletizing tasks under 4 conditions: pallet to flat cart, pallet to adjustable cart, carousel to flat cart, and carousel to adjustable cart. The carousel reduced the LI by about 20% while the adjustable cart had limited impact. Based on the NIOSH LI, the carousel provide a reduction in risk but remained elevated (e.g. LI&gt;3.0) and the adjustable cart was less effective (LI&gt;4.6). Caution is needed to interpret these results as the spine loads may be significantly reduced and provide a different picture.

The NIOSH Lifting Equation and Low-Back Pain, Part 2

The aim of this study was to investigate the relationship between the revised NIOSH lifting equation (RNLE) and risk of seeking care for low-back pain (SC-LBP). The RNLE is commonly used to quantify low-back physical stressors from lifting/lowering of loads in workplaces. There is no prospective study on relationship between RNLE and SC-LBP. A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current low-back pain were obtained at baseline. The cohort was followed monthly to ascertain SC-LBP and quarterly to determine changes in physical exposure. Associations between SC-LBP and both the peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. SC-LBP lifetime prevalence at baseline was 31.9%, and there were 24 incident cases during follow-up. Factors predicting SC-LBP included job physical exposure (PLI and PCLI), history of low-back pain, age, female gender, and lower body mass index. In adjusted models, risk (hazard ratio [HR]) increased per unit increase in PLI and PCLI (p = .03 and .02, and maximum HR = 23.0 and 21.9, respectively). Whereas PCLI suggested a continuous increase in risk with an increase in PCLI, the PLI showed elevated, though somewhat reduced, risk at higher exposures (HR = 14.9 at PLI = 6). Job physical stressors are associated with increased risk of SC-LBP. Data suggest that both the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.