Evaluation of ergonomic risk factors by OCRA method in assembly industry

In order to assess specific factors There are several risk assessment methods including occupational repetitive action (OCRA) which is used in industries with repetitive motion, increased force, awkward posture, and lack of recovery periods.These risk factors exists in assembly lines, and the purpose of this investigation is assessment of ergonomic risk factors by OCRA method in assembly lines. Job analysis was done by observation and each job was degraded to tasks, actions and movements. Nordic standard questionnaire (NMQ) was used for demographic data and upper limbs MSD complaints in 10 factories. Two assembly lines were assessed and 166 OCRA indices were obtained and analyzed with OCRA software and SPSS software using chi square and paired t- test. The results showed that in line B the highest risk in right hand was 66% (low risk), and in line Awas 44% (high risk). In line B the highest risk in left hand was 53.19% (low risk) and in line A was 38% (low risk). The mean value of right and left hand exposure indices was insignificantly different (p<0.001). There was significant relationship between UEMSDs and hand type (p<0.001) and between UEMSDs and age (p<0.001). Line Ahad more risk than line B with respect to repetitive movements. In line A the highest risk was in the right hand whereas in line B highest risk was seen in the left hand. As the most prevalent complaints were in wrists and fingers. We conclude that these parts are more involved upper limbs in assembly line. Finally the OCRA method can be a useful method for evaluation of UEMSDs in repetitive tasks of the assembly industry.