Occupational Repetitive Action Index Research Articles

IMPROVEMENT OF WORK METHOD TO REDUCE REPETITIVE WORK IN PT. TRIJAYA PLASTIK UTAMA WITH OCRA METHOD

PT. Trijaya Plastik Utama is a company that manufactures raincoats. Based on the results of interviews with workers in 3 production departments, most experienced complaints in the upper limbs, especially the neck, back, and hands. Most of the work does repetitive activities with long cycles, so the nature of the work is suspected to cause musculoskeletal disorders for the operator. This study aims to identify the presence of musculoskeletal risks due to repetitive work using the Occupational Repetitive Action (OCRA) method. Based on the identification results of each department section, the packing section has the highest OCRA index value with a value of 3.86 for the right hand and 3.01 for the left hand. Improvement efforts to reduce risk due to repetitive work is to apply the concept of Eliminate, Combine, Re-Arrange and Simplify (ECRS) and the proposed design of work facilities. As a result, the OCRA index value dropped to 0.95 for the right hand and 0.85 for the left hand where the conditions were optimal

Effects of OCRA parameters and learning rate on machine scheduling

In this paper, the effects of Occupational Repetitive Actions (OCRA) parameters, learning rate on process times, and machine scheduling were investigated. We propose that Work-Related Musculoskeletal Disorder (WMSD) risks should be taken into account in machine scheduling. To the best of our knowledge, none of the earlier methods simultaneously considered effects of WMSD risks and the learning rate on processing times. The OCRA index method was employed for WMSD risk assessments. In this context, OCRA parameters such as duration, recovery, force, posture, and repetitiveness were analyzed. Observed process times of each factor were obtained from video records. Statistical analysis (ANOVA) revealed a positive (r=0.616) relationship on processing times with OCRA indexes in independent t-tests at significance level 0.05. To investigate the effects of WMSD risk, our Scheduling with Learning Effect under Risk Deterioration (SLE&RD) model was compared with six existing machine scheduling models in the literature. Detailed machine scheduling instances of 9 jobs with WMSD risks revealed that job sequences and makespan varied under different scenarios. This means that WMSD risks and OCRA factors affect machine scheduling with a deterioration effect. The results confirmed that when WMSD risks are included, actual process time and makespan move closer to observed process times. To obtain more accurate machine scheduling, which is close to real-life applications, WMSD risks, and learning rates should be considered simultaneously. The SLE&RD model is promising in machine scheduling for real-life problems and presents a holistic view of machine scheduling and WMSD risks.

Occupational Risk Evaluation Through Infrared Thermography: Development and Proposal of a Rapid Screening Tool for Risk Assessment Arising from Repetitive Actions of the Upper Limbs.

Risk analysis is one of the main tools for preventing the occurrence of Work-Related Musculoskeletal Disorders. New methods of risk analysis should seek to be more agile and simplified, encouraging them to be widely applied in work environments. This paper aimed to develop a rapid tool for assessing the risk of developing Work-Related Musculoskeletal Disorders (WMSDs) arising from repetitive actions of the upper limbs, while using a thermographic camera to measure skin temperature variation. A workstation was developed in an environmentally controlled laboratory, representing the five levels of risk presented by the Occupational Repetitive Actions Index (OCRA) Index, which were performed by 32 participants for 20 min. each level. There was a significant change in forearm skin temperature at all risk levels (p < 0.001), with a positive linear correlation (r = 0.658 and p < 0.001), which led the authors to perform linear regression analysis for the forearm region. The Predicted OCRA Index calculation equation was successfully developed (R = 0.767 and R² = 0.588), while using as independent variables: air temperature and temperature variation of the forearm skin. The Predicted OCRA Index can be applied as a screening tool for large numbers of workers in the same company or sector, due to its speed of application and the determination of risk level, but it does not replace the original OCRA Index.

The prevalence of musculoskeletal discomforts and its relation with work posture in Carpet Weavers, Boshruyeh City

Introduction: Carpet industry is one of the most important, dangerous and traditional industries in Iran. Non-Ergonomic factors such as non-standard work tools, inappropriate physical postures, long hours of work and insufficient rest of carpet weavers can lead to musculoskeletal disorders. The purpose of this study was to determine the prevalence of musculoskeletal discomfort and its relationship with posture in rural carpet weavers in Boshruyeh city.&#x0D; Methods: This study is descriptive, analytical and cross-sectional. The sampling method was census-based and included all rural carpet weavers in Boshruyeh city who were active at least 6 months prior to the beginning of the study and were willing to cooperate (62 people). In order to investigate musculoskeletal discomforts, used from Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) and for posture assessment, The Occupational Repetitive Action Index (OCRA) method was used. The collected data by using SPSS software IBM 24 (Pearson correlation test) was analyzed.&#x0D; Results: The results showed that 98.39% of the workers felt discomfort at least in one of the 20 assessed regions. The most common discomfort of carpet weavers was 72.88% in the lower back region and the lowest incidence of discomfort was 9.68% in the hip/buttocks. There was a significant statistical relationship between scores of musculoskeletal discomforts in 11of 20 assessed regions with OCRA score (p &lt;0.05), There was also a significant statistical relationship between age, work hours and work experience with CMDQ score (p &lt;0.05).&#x0D; Conclusions: It seems Insufficient rest, Repetitive work, and incorrect posture are of factors affecting the musculoskeletal discomfort.observe the principles of ergonomics, especially having proper postures and regular rest along with stretching can be helpful in reducing the incidence of discomfort and musculoskeletal disorders.

The comparison of ergonomic risk assessment results using job strain index and OCRA methods

Musculoskeletal Disorder (MDSs) is a real problem in terms of ergonomics. MSD is a muscle/pain disorder which is frequently undergone by operators after doing work, e.g. in the press line of a printing company. Some activities in press line are lifting books, reaching out the engine levers, and turning the engine levers. Many MSDs are undergone by operators, such as aches in the upper arms, hands, feet, and back. This is caused by excessive burdens and wrong posture when doing work. This study is aimed to compare the assessment results of operators’ body posture by using OCRA and JSI methods. OCRA (Occupational Repetitive Action) Index is a method used to evaluate and analyze a job. Meanwhile, Job Strain Index (JSI) is a method used to estimate the risk of pain in the upper body. Evaluation is carried out on repetitive activities. Based on the calculation results, the OCRA values obtained are 3.35 for the right hand and 1.13 for the left hand. Meanwhile, JSI value for the right hand is 9 and the left hand is 4.5. The results of the assessment indicate that these activities are categorized as high-risk so and need to be corrected. The author’s recommendation is by adding the number of operators on the press line.

Assessment of exposure packaging worker and designing work methods using OCRA index in fertilizer producer company

Repetitive tasks carried out by packaging workers of fertilizer producer company. These task led to some complains of pain and fatigue on upper body part of the workers based on Nordic Body Maps (NBM) questionnaire. This is because the workers work continuously for eight hours per shift and no recovery period. This study aims to determine risk level of musculoskeletal disorders and break time calculation. In this study, using Occupational Repetitive Actions (OCRA) index to reduce the risk level. The samples according to expert judgement criteria are three workers (packer clamper, packer tailor and loader). The improvement in this study is designing work methods with break time calculation. This improvement shows the risk reduction on the left hand of the packer clamper from 4,2 to 3,4 and the right hand from 9,9 to 8,2. Risk reduction on the left hand of the packer tailor from 3,44 to 2,2 and the right hand from 5,7 to 2,26 while the risk level on the left hand of loader from 1,4 to 0,87 and in the right hand from 2,17 to 1,18.

The problem of assigning rest times to reduce physical ergonomic risk at assembly lines

Line balancing and job rotation have been recently found to be effective methods to reduce workers’ ergonomic risks since the design/planning phase of assembly lines, and at the same time to limit performances deterioration and/or costs increments. As far as we know, there are no papers in the literature that deals with the problem of assigning rest times to workers in assembly lines with the aim to reduce their ergonomic workload. In the paper the problem of assigning rest times to workers in assembly lines is considered (Rest Time Assignment Problem). We show how rest times assignment affects ergonomic risk of workers in mixed-model assembly lines when this is evaluated through the Occupational Repetitive Action index (OCRA), and suggest and approach to simultaneously find solutions for the Assembly Line Balancing Problem and the Rest Time Assignment Problem.

Ergonomic Analysis of the Work Condition in Aluminum Crafts Industry

Indonesia has plenty of abundant natural wealth. This natural wealth produces natural materials that can be utilized as a craft product. The craft workers generally still work manually and the work is done repeatedly in one cycle so it is very susceptible to musculoskeletal disorders. Musculoskeletal disorders will cause decrease of worker’s effectiveness and efficiency in completing the task. Thus, this fact has some adverse impact for the company. The purpose of this study is to analyze some task in manufacturing a traditional cooking tool (griddle) which encompasses mold of the griddle, refine of the griddle and the finishing touch by using the Occupational Repetitive Action Index (OCRA index) method. This method consists of high frequency movements, large forces, awkward postures, insufficient resting time and other factor such as vibration. Result of this study shows that in the molding operation, the worker has uncertain and medium risk on right hand in manufacturing small and large size of griddle with OCRA index is 2.5 and 5.3 respectively. In the refining operation the worker has light and medium risk on left hand in manufacturing small and large size with OCRA index is 3.6 and 5.8 using grinding machine and 5.8, 5.2, 6.3 and 5.0 using miser tool. In finishing operation, the worker has high risk on right hand in numbering of code griddle and has medium risk on right hand and medium on left hand in labeling with OCRA index is 9, 6.1 and 6.8 While in assembling operation the worker has no risk. Score that it indicates the risk level of the task in such job. Thus the following actions are to improve the work condition ergonomicly in all operation in alumunium craft.

Beyond OCRA: Predictive UL-WMSD risk assessment for safe assembly design

In terms of occupational safety, one of the most important areas to consider is that of Upper-Limb Work-related MusculoSkeletal Disorders (UL-WMSDs), i.e. work-related disorders due to biomechanical overload of the upper limbs caused by protracted movements and/or repeated efforts throughout the workday. To estimate the risk associated with these disorders, the method known as the OCRA (OCcupational Repetitive Actions) Index is universally accepted; based on observation, it provides an index whose value is related to the expected percentage of pathological cases among the entire working population. This work introduces a different perspective to the problem in order to provide designers with a method – PRASAD: Predictive Risk Assessment for Safe Assembly Design – that makes them aware of the issues related to UL-WMSDs, starting from the earliest stages of the design of a new product and the related assembly workstation, well earlier than observing the activities associated to its production, that is when the assembly workstation is fully set and running. The main advantage of the method lies in the outcome, the PRASAD Index, which is fully comparable with the OCRA Index, so that the proposal leverages on the well-known OCRA standard approach. The new method, aimed at a use in the design phase (of a new workstation for a new product), is potentially useful for a conventional risk assessment of existing workstations as well: it combines the rapidity of a checklist for the initial screening with a level of detail that is characteristic of advanced methods, such as the OCRA Index. Finally, PRASAD represents an innovation in the risk assessment of UL-WMSDs because of its feature of modelling the concept of “Technical Actions”, which enables estimating (and taking into account) the repetitiveness of tasks, based on technical design and production management data.

Analytical characterization of movements of the spinal column and risk assessment due to repeated movements of the upper limbs of building painters

Manual activities of construction workers may induce musculoskeletal disorders. This study on a group of painters aimed to analytically characterize movements of the spinal column by both lumbar motion monitor and television cameras and to determine, using the Occupational Repetitive Actions (OCRA) Index method, the risk exerted by repeated movements of the upper limbs. The main results are: painting with a roller generally exposes workers to a lesser risk for upper limbs than painting with a brush; a roller-stick fixed at the wrong length can lead to stretching of the back at lumbar and cervical levels; to remain within the range of ‘acceptable risk’ (OCRA Index evaluation), a worker should not paint a vertical wall for over 3 h if using a roller and 2.5 h if painting with a brush; and, on average, a painter who paints for 5 h in a day lifts the bucket about 120,140 times.

Ergonomic risk factors in bicycle repairing units at Jabalpur.

Bicycle repairing at Jabalpur in the Madhya Pradesh state of India employs a large number of local youths. In this sector occupational ergonomic issues of Work Related Musculoskeletal Disorders (WMSDs) are a big problem and a threat to this profession. The objective of this study was to identify the different ergonomic risk factors for Work Related Musculoskeletal Disorders (WMSDs) in the job of bicycle repairing. Still photography and video photography was used to record different activities. Different types of non-invasive tools like Rapid Entire Body Assessment (REBA), Rapid Upper Limb Assessment (RULA), and Occupational Repetitive Action Index (OCRA) were used. Psychophysical measures were investigated by rated perceived exertion scale and visual analogue scale. OVAKO scores (4), REBA scores (13/13), RULA scores (8/8) were extremely high, indicating immediate intervention. The results indicate that the different tasks in this profession are in the high risk category and demands immediate ergonomic intervention in the form of re-design of the tools used and work station or/and the design of the work process.

Comparison of risk assessment procedures used in OCRA and ULRA methods

The aim of this study was to analyse the convergence of two methods by comparing exposure and the assessed risk of developing musculoskeletal disorders at 18 repetitive task workstations. The already established occupational repetitive actions (OCRA) and the recently developed upper limb risk assessment (ULRA) produce correlated results (R = 0.84, p = 0.0001). A discussion of the factors that influence the values of the OCRA index and ULRA's repetitive task indicator shows that both similarities and differences in the results produced by the two methods can arise from the concepts that underlie them. The assessment procedure and mathematical calculations that the basic parameters are subjected to are crucial to the results of risk assessment. The way the basic parameters are defined influences the assessment of exposure and risk assessment to a lesser degree. The analysis also proved that not always do great differences in load indicator values result in differences in risk zones.

Assessment of physical risk factors among artisans using occupational repetitive actions and Nordic questionnaire

Aims: The aims of present study is to determine the level of exposure to physical risk factors of work related repetitive movements in the upper limbs among the artisans in Isfahan, using occupational repetitive actions index and the Nordic Questionnaire. Material and Methods: In this cross-sectional study, the study population consisted of 94 males employed in Artisan production. The tools that be used for assessing physical ergonomic risk factors among artisans was Nordic Questionnaire and OCRA index. The different handicraft tasks and work activities included: Simple etching, embossing, reticular embossing, enameling, tiling, illumination, inlay, copper smithing and, miniature painting have been chosen for the study. The Study was carried out on the both left and right hands. The results were analyzed by statistical tests included Chi square, Kruskal Wallis and one-way variance analysis. Results: The highest OCRA index score was related to simple etching job, and the other tasks such as embossing, copper smithing, reticular embossing, tiling, miniature painting, and illumination were in lower risk category. Our finding showed that there are a significant difference between OCRA scores of the various jobs (P value Conclusion: Our assessment showed that in overall there are different physical risk factors among artisans which make them susceptible to musculoskeletal disorders.

Ergonomic Design Issues in Some Craft Sectors of Jaipur

ABSTRACTThis paper investigates the risk factors associated with work-related musculoskeletal disorders in three craft sectors of Jaipur in India. The sectors considered were those of blue pottery, handloom and gota patti. Observational methods like Rapid Entire Body Assessment (REBA), Rapid Upper Limb Assessment (RULA) and OVAKO for postural analysis were applied. The Occupational Repetitive Action Index (OCRA) and Strain Index (SI) were also used to gauge the extent of repetitiveness and strain in the work. These investigations gave valuable insight into the fact that many of the working conditions were hazardous and demanded immediate intervention. It also indicated that the physical design of tools and workstations alone would not solve the problems. The designer needs to look into non-physical design issues like the work/rest cycle, process design, physical exercise and training to effectively control the different risk factors in the genesis of work-related musculoskeletal disorders.

The Risk of Musculoskeletal Disorders for Workers due to Repetitive Movements during Tomato Harvesting

Tomatoes are the most common crop in Italy. The production cycle requires operations in the field and factory that can cause musculoskeletal disorders due to the repetitive movements of the upper limbs of the workers employed in the sorting phase. This research aims to evaluate these risks using the OCRA (occupational repetitive actions) index method This method is based firstly on the calculation of a maximum number of recommended actions, related to the way the operation is performed, and secondly on a comparison of the number of actions effectively carried out by the upper limb with the recommended calculated value. The results of the risk evaluation for workers who manually sort tomatoes during harvest showed a risk for the workers, with an exposure index greater than 20; the OCRA index defines an index higher than 3.5 as unacceptable. The present trend of replacing manual sorting onboard a vehicle with optical sorters seems to be appropriate to reduce the risk of work-related musculoskeletal disorders (WMSDs) and is supported from both a financial point of view and as a quality control measure.

Evaluating ergonomic risk factors in non-regulated stone carving units of Jaipur

Stone carving at Jaipur in Rajasthan state of India, is a traditional craft employing a large number of local youths. As an unorganized sector problems are many ranging from lack of benefits to occupational ergonomic issues of Work Related Musculoskeletal Disorders(WMSDs) and injury to body parts. Twenty five male workers were selected in each of the three sections of a stone carving unit. The focus was to identify different ergonomic risk factors associated in this profession from the field. Still photography and video photography was used to record different activities. Different types of non invasive tools like Rapid Entire Body Assessment (REBA), Rapid Upper Limb Assessment (RULA), Occupational Repetitive Action Index (OCRA) were used. Psychophysical measures were investigated by Body part discomfort map, rated perceived exertion scale and visual analogue scale. Objective measurements (heart arte and skin temperature) were recorded with stop watch and digital thermometer. The working heart rate after 30 minutes of work was 112.4 beats per minute categorizing the work as moderately heavy. Postural analysis by REBA indicated high score (13/13). Similarly postural analysis by RULA showed high score (7/7). These indicate vulnerability of many of the postures to musculoskeletal disorders and injury. The study indicates that majority of the activities are in the high risk category and demands immediate ergonomic intervention in the form of tool, workstation and process design. This could be done by involving different Non Government Organizations (NGOs), political parties, and the Human Rights Department both at the center and at the state level.