ارزیابی ارگونومیکی

Musculoskeletal disorders are one of the most common causes of occupational injuries that mainly affect the low back, neck, and upper limbs. Preventing these discomforts requires assessing workplace posture using ergonomic job analysis methods. The aim of this study was to determine the rate of musculoskeletal injuries of mechanical repairs using REBA method in 2018 in Sarcheshmeh copper mine.

In this descriptive-analytical study, the workplace posture of 65 mechanical repairs were evaluated using REBA method. The prevalence of musculoskeletal disorders was also obtained using the Nordic questionnaire. The collected data were analyzed by SPSS 20.

In this study, the prevalence of wrist discomfort was 43.07%, neck 18.46%, shoulder 33.84%, low back 53.85%, and leg 27.70%. Regarding the risk level of the right limb, 9.25% of the subjects were at a low level, 46.15% at a medium level, 32.30% at a high level, and 12.30% at a very high level. Also, regarding the risk level of the left limb, 4.62% of the subjects were at a low level, 64.61% at a medium level, 26.15% at a high level, and 4.62% at a very high level.

These results indicated that the workplace posture of the subjects needed to be improved. To prevent the occurrence of these disorders, education is required to recognize biomechanical risk factors and correct methods of working, use of appropriate tools and appropriate to the work process, and improvement and control of stressors and environmental factors.

In recent years, due to the rapid growth of metropolitan cities and the shortage of urban public transport means, including urban bus transportation, many people are forced to travel in a standing position when using these vehicles. This situation may cause pain and discomfort and non-collision injuries for passengers. The purpose of this study was ergonomic assessment of the sit-standing seat in passengers standing on urban buses.

To do this study, 8 young people with a mean age of 25.25±2.12 years were enrolled. For evaluation and assessing the effect of sit-standing seat two methods of surface Electromyography (sEMG) and Borg scale scores were applied in Fall 2018. The data was analyzed using SPSS 24.

In all body parts, except for the hip, the mean scoring of Borg’s scale for perceived discomfort in sit-standing position was less than standing position. Also, the amount of contractile activity of the leg muscles in sit-standing position was significantly lower than the standing position (P<0.05).

Considering the results obtained from the Borg scale scores and the contraction activity of the leg muscles as a result of the use of the mentioned seat, which led to a reduction in the level of discomfort and the leg muscles contraction, it is recommended to apply the sit-stand seat instead of being in a standing position.