ergonomical study of the postures of doing in tailors, shoe makers, saddlers and carpet makers by OCRA[1] analysis method

ABSTRACT

Among the work-rated musculo skeletal disorders, those of upper limbs cover the most. This is caused because of tenderness and vulnerability of these limbs compared with lower limbs from one hand, and more involvement of these limbs to the activities from the other. As a consequence the limbs are more exposed to dagerous factors causing musculoskeletal disorders, thus more likely to be affected by musculoskeletal disorders. One of the methods to analyse the dangerous factors causing upper limbs musculuskeletal disorders is occupational repetitive actions [OCRA]. The method is a job analysing tool which is applied to perform a total and effective estimation toward various risky factors affecting upper limbs [ie. shoulders, elbows, wrists, hands and fingers]. The present study is carried out in an attempt to surveying and ergonomic analysing the work done postures of tailors, shoe makers, saddlery and carpet makers in the some present workshops of Tehran province prisons by OCRA Index method. This study is of analytic - descriptive type which is done on a sectional basis [cross - sectional]. The target population were chosen as 496 prisoners to carry out NORDIC questionnaire method and also OCRA Index. In questionnaire method four job as tailoring [203 prisoners], shoe making [211 prisoners], saddlery [67 prisoners] and carpet making [15 prisoners] were analysed and in OCRA method, 17 job/tasks as tailoring [7tasks], shoe making [5 tasks], saddlery [4tasks] and carpet making [I task] were analyzed for right hand and also 17 job/tasks for left hand. The results of this study that acquired by x[2] test, Me Nemar test,Kruskal-Wallis test and independent t-test, as follows; unequality in ratio of musculuskeletal disorders of upper limbs in the four mentioned jobs [P value = 0.003], unequality of means of OCRA index between the above four jobs [P value < 0.001], present a significant relationship between level of OCRA index and the kind of job, were proved. [P value < 0.001]. The highest OCRA index numbers were achieved for the Carpet making task and Overall, Carpet making was assessed as the most dangerous job and Shoe making, Tailoring and Saddlery came in next grades of risk, respectively [P value< 0.001]