Comparison the results of workers upper limb musculoskeletal disorders in companies of detergents and assembly with strain index and hand activity level methods

Background: Upper limb musculoskeletal disorders are related with repetitive work activities including force, posture and duration of work. Objectives: The aims of this study were identification of prone occupations to upper limb musculoskeletal disorders, assessment of jobs in two companies of producing detergents and assembly by two methods of strain index (SI) and hand activity level (HAL). Methods: In this study descriptive-analytical and cross sectional that was done in 2015 in Qazvin, 50 subjects from practitioners of all of occupations were randomly selected (25 jobs) from two companies of producing detergents and assembly. Data were collected by body map and assessment methods of the strain index and HAL. Statistical analysis done by Spearman correlation coefficient and chi-square tests in SPSS 16 software. Findings: The most of the prevalence musculoskeletal disorders were reported in the elbow 16.66% and in the wrist and shoulder 23.08% in producing detergents and in assembly factories respectively. According to the investigation by two methods SI and HAL, seven jobs (58.3%) in producing detergents and three jobs (23.1%) in assembly factories were in situation of caution or hazard. The results of the assessment upper limb by two methods showed significant correlation together (r=0.615 in producing detergents and r=0.603 in assembly factories with P<0.001). Also, there was a significant relation between the prevalence of musculoskeletal in hand-fingers with strain index (c2=6.46, df=2, P=0.039). Conclusion: The results of this study shows that the methods of strain index and hand activity level have significant correlation in the assessment of repetitive jobs and risk of upper limb musculoskeletal disorders.