Correlation of results of three methods OCRA Index, Strain Index, ACGIH HAL to evaluate the risk of upper extremity musculoskeletal disorders

Three methods of OCRA Index، Strain Index and ACGIH HAL are proposed to assess risk factors of upper extremity musculoskeletal disorders. These methods are important in work environments to evaluate musculoskeletal disorders. Thus the aim of this study is to determine the correlation between the results of the above mentioned methods. In this cross - sectional study، a total of 150 job tasks studied in four industries. For each task، not only video taping was used to record the duration of a full cycle but also tasks were evaluated according to instructions. The correlation coefficient and the coefficient of agreement were analysed using SPSS16 and R software. Correlation between the results of risk assessment methods OCRA and SI for right and left hand، were acceptable correlation (0. 751) and (0. 726) respectively. Also the result of agreement between the methods OCRA and HAL for right and left hands، were (0. 526) and (0. 595) respectively. This study showed that none of the two methods do not fully agree. One of the source of differences is the number and types of variables and their effects on the final score of the methods.