Correlations in between EAWS and OCRA Index concerning the repetitive loads of the upper limbs in automobile manufacturing industries

Upper limbs repetitive tasks are one of the main sources of risk for the workers of the manufacturing industries and the standards ISO 11228-3 and EN 1005-5 addressed this issue since 2007. EAWS (European Assembly Worksheet) is a 1st level ergonomic risk assessment method and it provides in its 4th section a score to measure the load level for the upper limbs based on a traffic light scheme. According to the relevant ISO/CEN standards, the OCRA Index is the preferred system to refer to in the evaluation of the biomechanical stress of hand-harm-shoulder system. This correlation study is based on a 45 workstations sample coming from the automobile manufacturing industry. According to the results, EAWS4 shows an excellent correlation with OCRA index (Spearman's rho correlation index 0.95). Being EAWS based on biometric statistical data distribution, its typical application is the process design phase, but adopting a conservative approach in the interpretation of EAWS4 score for risk mapping purposes, it provides an equivalent "reaction" pattern (countermeasures to be taken in the production phase) with respect of OCRA Index with an Odds Ratio ranging from 0.89 (OR-matched) to 1.00 (OR-conservative).     

Relationship between productivity, quality and musculoskeletal disorder risk among deboning workers in a Chilean salmon industry

The purpose of this ergonomic investigation is to establish a relationship between quality, productivity and risk of musculoskeletal disorder (MSD) in manual bone-removal process in the salmon fish industry. The method consists in a follow up study of 14 workers in a lane that processes salmon steak. Time between each steak (work cycle), quality of the steak's meat through inspection of deepness and length of the gapping generated by the manual bone-removal process and risk for musculoskeletal disorders through OCRA method were considered for this study. IMC and musculoskeletal Nordic Questionnaire of Kourinka were applied to the workers evaluated. Fourteen women worker's completed the evaluation, age 37.67 ± 8.1, with 65.27 ± 34.41 months of experience, with an IMC of 27.18 ± 3.87 (1.52 ± 0.057 meters of height) at the time of the evaluation. Time for deboning per steak averaged 38 ± 14 seconds with 68.33 ± 14.79 steaks per hour per worker. In quality terms, 74% of the steaks were qualified as "premium steaks" and 26% as "grade or industrial" (lower category and cheapest price). OCRA index for the right hand average 13.79 ± 4.59 and 3.59 ± 0.41 for the left hand. From Nordic questionnaire 80% of the workers manifested musculoskeletal symptoms in the right hand/wrist, followed up by shoulder with 60% of the workers and arm/elbow with over 50%. There was no statistically significant relationship between productivity and quality of the steak after manual bone removal process and between quality and MSD risk. However, there was a statistically significant relationship between productivity and MSD risk (p<0.05). Discussion around the results allows to see complementary results that did have strong correlation between MSD risk and the presence of lower grade salmon steaks and between areas that present musculoskeletal symptoms (MSS) and the intensity of the MSS (p<0.05). The results showed that further research is needed to validate these relationships, due to the increasing demands of health-care services from this productive sector, considering its importance for this region.     

Association between repetitive work and occupational cold exposure

Occupational cold exposure is an important risk factor that increases stress at work and can induce many health effects like diseases and symptoms related to cold, including work-related musculoskeletal disorders. The methodological procedures were performed to measure these environmental variables as recommended by the ISO 7726/85. For the analysis of repetitiveness was used the OCRA checklist and evaluation of musculoskeletal morbidity conducted by the Nordic Musculoskeletal Questionnaire. So the objective of this study was to investigate the correlation between cold environmental variables and prevalence of musculoskeletal morbidity in the repetitive work. Was found association between work in cutting and boning sector (occupational cold and repetitive work) and the presence of musculoskeletal morbidity, with a significance of 99%.     

Occupational stress and biomechanical risk in a high fashion clothing company

Psychosocial discomfort may amplify job-related risk factors. The aim of this study is to evaluate job stress in a high fashion clothing company with upper limb biomechanical overload due to repetitive and forceful manual activities. Biomechanical risk was analyzed and in part reduced using the OCRA Check list. A total of 518 workers (433 females and 85 males) were investigated to determine anxiety (by STAI 1 and 2), occupational stress (using the Italian version of the Karasek Job Content Questionnaire) and perception of symptoms. Final biomechanical assessment did not reveal high risk jobs, except for cutting. Although the perception of anxiety and job insecurity was within the normal range, all the workers showed a high level of job strain (correlated with the perception of symptoms) due, probably, to very low decision latitude. It was suggested that job strain may increase the perception of symptoms. Moreover, the result of this study indicates that musculoskeletal overload has to be further analyzed since its low level is not in agreement with the level of discomfort due to the repetitive tasks.     

The reality of the women who make our lives easier: experience in a company that assemblies electric motors in Venezuela

Objective: intervene a workline throughout ergonomic approach to diminish incidence of Carpal Tunnel Syndrome (CTS). Methods and Materials: an ergonomic intervention study was developed in workstations with highest index of musculoskeletal disorder (MED) associated to cumulative trauma. The Deparis method, Reba and Ocra check list methods were used, also morbility reviewes. National and international ethics criteria were carried out. Results: workers identified 3 fundamental issues using the Deparis method: repetitive activities, postures adopted and uncomfortable furniture. The analysis of the workstation with Reba and Ocra methods before the changes, evidenciated that 56% of postures adopted were high risk postures, the 44% remaining were medium and low-risk. Following the active pause program (APP), furniture changes and work rhythm decrease, was noted that the risk of suffering MED decreased. The morbility review, drop in consults of musculoskeletal system (MES) related to CTS observed. The APP was well accepted by women, but not initially men. Discussion: the research show that when the work rhythm decreases, the symptom of MES related to CTS have a remarkable decrease, also that changes in the furniture, generate great ergonomic differences and changes in the work environment are not possible if workers don't empower the tools to make-it.     

Biomechanical overload in multiple tasks with weekly and annual cycle: practical experiences in the field of cleaning and packaging of fruit

The OCRA method is the reference method chosen in ISO (ISO 11228-3) and CEN (EN 1005-5) standards regarding risk assessment and management of upper limbs repetitive movements and exertions. The method consists of two specific tools (OCRA index and OCRA checklist). In this paper special attention will be devoted to the procedures for the analysis of multiple repetitive tasks.When computing the OCRA index (checklist score) considering the presence of more than one repetitive task, a "traditional" procedure has been previously proposed. This approach, whose results could be defined as "time weighted average", seems to be appropriate when considering rotations among tasks that are performed almost once every hour. On the contrary, when rotation among repetitive tasks is less frequent the "time weighted average" approach could result into an underestimation of the exposure level. For those scenarios an alternative approach is based on a concept that the most stressful task is the minimum starting point. A peculiar procedure allows to exactly estimate the resulting index within this range of minimum to maximum values. It is possible to apply this approach also for job rotation with weekly or monthly or annual cycle typical of agriculture, supermarket, cleaning sectors. This paper shows criteria and results in two working situation: cleaning (weekly cycle) and packaging of fruit (annual cycle).     

The ergonomics approach for thin film transistor-liquid crystal display manufacturing process

The thin film transistor-liquid crystal display (TFT-LCD) has been used all over the world. Although the manufacture process of TFT-LCD was highly automated, employees are hired to do manual job in module assembly process. The operators may have high risk of musculoskeletal disorders because of the long work hours and the repetitive activities in an unfitted work station. The tools of this study were questionnaire, checklist and to evaluate the work place design. The result shows that the participants reported high musculoskeletal disorder symptoms in shoulder (59.8%), neck (49.5%), wrist (39.5%), and upper back (30.6%). And, to reduce the ergonomic risk factors, revising the height of the work benches, chairs and redesigning the truck to decrease the chance of unsuitable positions were recommended and to reduce other ergonomics hazards and seta good human machine interface and appropriate job design.     

Relationship between construction workers' musculoskeletal disorders and occupational health service activities

Construction work consists of numerous factors that influence workers' occupational health and that load the musculoskeletal system in particular. Musculoskeletal disorders are responsible for over a third of all sick leaves lasting over nine days in the construction industry. Occupational health services (OHS) were organized for 85% of the construction workers in our study. The proportion of construction workers who had suffered from chronic or repetitive neck and shoulder, shoulder or arm, or low-back disorders was 55.6%, 44.8% and 42.1%, respectively. Those who felt that they had received enough information, advice or guidance from OHS concerning work posture, work performance or work tools were more often those who had not suffered from shoulder or arm disorders (60.9% vs. 39.1%, p=.024, respectively) or low-back disorders (63.6% vs. 36.4%, p=.034, respectively) during the last month than those who had. Those who had received enough support from OHS concerning maintenance of work ability were more often workers who had not suffered from low-back disorders during the last month than those who had (63.3% vs. 36.7%, p=.004, respectively). OHS should focus more on workers who would really benefit from their activities at a particular time and in a particular situation (primary, secondary or tertiary prevention) and who are themselves devoted to improving their health.     

Psychosocial indicators among aircraft maintenance workers with and without neck and shoulder musculoskeletal symptoms

In the aircraft maintenance industry, most of workers performs manual handling tasks of different materials, varying from small objects up to large pieces of the aircraft. It can increase the occurrence of work-related musculoskeletal disorders (WMSDs), which are strongly associated with high physical demands required by the task. Moreover, psychosocial demands are considered as risk factors for musculoskeletal disorders in both the upper limbs and lumbar spine. Thus, the objective of this study was to assess psychosocial indicators among aircraft maintenance workers according to the presence of neck and shoulder musculoskeletal symptoms. Eighty workers of an aircraft maintenance company were evaluated (32.69 ± 8.25 years, 79.8 ± 13.4 kg, 175 ± 7 cm). According to physical examination, 50 workers were classified as asymptomatic (AS - 4.1 ± 3.17 positive signs) whilst 30 workers were classified as symptomatic (SS - 26.72 ± 11.44 positive signs). AS and SS have shown similar profile of demand (p = 0.62), control (p = 0.66) and social support (p = 0.74) according to the Job Content Questionnaire. However, the groups are different when considering work engagement variables. In general, SS have higher scores than AS (p < 0.05).     

Exposure assessment in different occupational groups at a hospital using Quick Exposure Check (QEC) - a pilot study

In order to test the feasibility and sensitivity of the ergonomic exposure assessment tool Quick Exposure Check (QEC), a pilot-study was conducted. The aim was to test QEC in different occupational groups to compare the exposure in the most common work task with the exposure in the work task perceived as the most strenuous for the neck/shoulder region, and to test intra-observer reliability. One experienced ergonomist observed 23 workers. The mean observation time was 45 minutes, waiting time and time for complementary questions included. The exposure scores varied between the different occupational groups as well as between workers within the occupational groups. Eighteen workers rated their most common work task as also being the most strenuous for the neck/shoulder region. For the remaining five workers, the mean exposure score were higher both for the neck and shoulder/arm in the most common work task. Intra-observer reliability shows agreement in 86% of the exposure interactions in the neck and in 71% in the shoulder/arm. QEC seems to fulfill the expectations of being a quick, sensible and practical exposure assessment tool that covers physical risk factors in the neck, upper extremities and low back.     

Developing a framework for assessing muscle effort and postures during computer work in the field: the effect of computer activities on neck/shoulder muscle effort and postures

The present study, a part of the PROOF (PRedicting Occupational biomechanics in OFfice workers) study, aimed to determine whether trapezius muscle effort was different across computer activities in a field study of computer workers, and also investigated whether head and shoulder postures were different across computer activities. One hundred twenty participants were measured continuously for two hours each while performing their own computer work. Keyboard activities were associated with the highest intensity of left and right trapezius muscle efforts, and mouse activities were associated with the smallest variability in left and right trapezius muscle efforts. Corresponding trends in head and shoulder postures included that the greatest head flexion and left and right shoulder internal rotation was observed during keyboard activities, and that the smallest variability in head flexion, head lateral tilt, and right shoulder internal rotation was observed during mouse activities. Identifying which muscle efforts and postures are different across computer activities is the first essential step for developing prediction rules for muscle efforts and postures, which can be used to link muscle efforts and postures to musculoskeletal symptoms in epidemiological studies.     

Long periods with uninterrupted muscle activity related to neck and shoulder pain

The aim was to analyze the relationship between periods with uninterrupted neck muscle activity for ≥ 4 min and neck and shoulder pain. The trapezius muscle activity was recorded bilaterally on 40 young workers and students during a full shift. Neck and shoulder pain, mechanical work load and decision control were reported at the same time as the muscle activity recording and 6 months later. A dose-response relationship was found between uninterrupted muscle activity and neck and shoulder pain, with a ten-fold higher risk for the group with more than half, compared to less than a third, of the shift with uninterrupted muscle activity. Self-reported mechanical work load showed a small but protective effect related to pain. Gender and decision control did not emerge as important risk factors in this model. In conclusion, this study indicates that work or other exposures that contains long periods with uninterrupted neck muscle activity of 4 min duration or longer should be minimized to reduce risk of neck and shoulder pain.     

Biomechanical modelling and evaluation of construction jobs for performance improvement

Occupational risk factors, such as awkward posture, repetition, lack of rest, insufficient illumination and heavy workload related to construction-related MMH activities may cause musculoskeletal disorders and poor performance of the workers, ergonomic design of construction worksystems was a critical need for improving their health and safety wherein a dynamic biomechanical models were required to be empirically developed and tested at a construction site of Tata Steel, the largest steel making company of India in private sector. In this study, a comprehensive framework is proposed for biomechanical evaluation of shovelling and grinding under diverse work environments. The benefit of such an analysis lies in its usefulness in setting guidelines for designing such jobs with minimization of risks of musculoskeletal disorders (MSDs) and enhancing correct methods of carrying out the jobs leading to reduced fatigue and physical stress. Data based on direct observations and videography were collected for the shovellers and grinders over a number of workcycles. Compressive forces and moments for a number of segments and joints are computed with respect to joint flexion and extension. The results indicate that moments and compressive forces at L5/S1 link are significant for shovellers while moments at elbow and wrist are significant for grinders.     

Participatory ergonomics and new work: reducing neck complaints in assembling

A participatory ergonomics approach is used to create a new work environment, which is aimed at reducing neck complaints in a cell phone assembly. The participatory ergonomics program included an initiative, problem identification, a selection of solutions, an implementation and evaluation. Twenty-eight women, all operators on an assembly line of cell phone boards, voluntarily participated in the design and evaluation of a device before implementing the device to all 215 employees performing that job. Prior to and after the intervention, RULA, comfort experiences and interviews were used. After introducing an adjustable angled small counter, these measurements showed both posture and comfort improvements. 90% of the 215 workers preferred the new work station and the neck complaints were reduced in 75% of the group. It also showed that the initial prototype needed to be modified as to reduce its sharp edges/compression points for the forearm. This project shows the importance of iterative testing and that an initiative by workers enlarges the chance of successful implementation.     

Application of the OCRA Method in the sugar cane harvest and its repercussion on the workers' health. Preliminary study

In Brazil the sugar ethanol industry has had strong growth in the last 10 years, sometimes due to the growing sugar exportation, sometimes due to the alcohol production for automobile fuel and for exportation. Despite the growing mechanization of the raw material harvest (sugar cane), the manual work still persists. The development of this article was based in the application of the OCRA Method in the sugar cane harvesting process, to evaluate the risks to the upper limbs by repetitive movements and epidemiologically prove the ratio risk x harm to the heath of the workers, as well as the probability of developing improvements in the working conditions. The analysis process consists of studying the work organization, the risks to the health of the worker and the distribution of the recovery periods during the working day.     

The risk of developing repetitive stress injury in seamstresses, in the clothing industry, under the perspective of ergonomic work analysis: a case study

This study presents the sewing task with the approach of the ergonomic analysis of the work, in the seam activity in a clothing industry to identify the relationship between the use of different sewing machines and the activity of sewing pants and blouses, which brings larger risk for the development of work related musculoskeletal disorders. It was done a study of transverse and exploratory cut, in that was used a methodology control of multiple analysis of variables. The population objective was the workers that exercise the activity in the section of makings, with 93 workers, being 54,8% sewing auxiliary and 45,2% dressmakers. Most is single (75,3%), has the 2nd complete degree (58,0%) and the medium age was 25 years old. As results were observed that the machines serger, zig zag and traveti are classified as of high risk of developing work related to musculoskeletal disorders, that the postures assumed during the execution of the tasks were classified as bad or terrible, and that the workstations were just classified as reasonable. It was concluded then, that a relationship exists among the task of sewing pants and blouses, and the risk of the development of work related to musculoskeletal disorders.     

Effect of ergonomic and workstyle risk factors on work related musculoskeletal disorders among IT professionals in India

'Workstyle' can be described as a mechanism by which ergonomic and psychosocial risk factors interact to affect the development, exacerbation and/or maintenance of upper limb pain and functional limitations. Workstyle is associated with the increase in the work demand. In today's life use of computer in the workplace is very common and it causes to increase the work demand among the workers who are working with computer. As work demand increase, according to the characteristic of workstyle, risk of the development of musculoskeletal disorders also increased. This study aimed at to findout the association between ergonomics risk factors, workstyle and WRMSD. Two hundred IT professionals participated in this study. Result revealed that most prevalenet body regions were lower back (20%), Upper back (16%) and shoulder (14%). Study result says that there is a positive association between workstyle score with musculoskeletal pain (r=0.85). Also it revealed that posture and regional pain is associated (r=0.62), per day use of computer and musculoskeletal pain (r=0.46), micro breaks and pain (r=0.87) and productivity and the pain (r=0.95). This study further validates these observations and extends support for the assessment of working postures and workstyle behaviors during the design of WMSD treatment.     

Members of the human body prone to musculoskeletal damages: a comparison between the sector of transportation and footwears production

This study present areas of the body more prone to develop diseases by musculoskeletal efforts, ie, RTD, in two companies of Paraiba, Brazil. To this end, was made a comparative analysis with respect to the type of work performed (standing, sitting) and the parts that suffer most discomfort after a day's work in a footwear industry and a bus transportation company. The quanti-qualitative research was conducted through semi-structured interviews with 227 employees in the period 2008 to 2009, having as methodological the tool diagram of painful areas of Corlett and Manenica. It was concluded that the areas most affected by musculoskeletal disorders are located in the neck (9,2%), backs (23,6%), shoulders (14,5%) and legs (11,3%), being usually caused by inappropriate postures, repetitive movements and work station no adequate the anthropometry of the users. Thus, we recommend the adoption of ergonomic measures that enable a healthy and safe environment for workers.     

Factors contributing to work related low back pain among personal care workers in old age

This study aims to preliminary explore the work related and individual factors that contributed to the occurrence of low back pain (LBP) that affected work activities of Personal Care Workers (PCWs). A cross-sectional study was conducted to 36 PCWs in an old age home of Hong Kong. The study is divided into three parts: 1) a questionnaire to document the workload exposure factors and the musculoskeletal symptoms survey of the PCWs, 2) work posture evaluation; and 3) an evaluation of the physical fitness and lifting capacity of the PCWs. Univariate analyses were used to explore the risk factors associated with LBP that affected work activities. The results indicated that individual physical profile and lifting capacities did not contribute to occurrence of low back pain at work. For the work demand factors, the perceived physical demands in lifting and lowering heavy objects, awkward sustain neck and back postures, loading on the back, and perceived effort of cleaning task contributed to the occurrence of LBP. For the physical environment factors, thermal stress and improper ventilation were associated with the occurrence of LBP cases. For the individual factor, LBP cases were associated with workers' self perceived muscular effort, and perceived risk of mental illness in response to work requirements.