Work-related musculoskeletal disorders (MSDs) are a major concern in industries and working environments. They cause not only suffering to the employee and decrease in performance, but also high economic losses to the companies and the society. Workers from assembly lines and machine operators are one of the most frequently affected working population. Moreover, one of the main types of MSDs in occupational environments are shoulder injuries. Exoskeletons have been applied and tested in rehabilitation and they are gaining ground in occupational environments as assistive devices to augment human force and minimize loads on muscles and joints. However, more evidence about the effects of several exoskeletons models in assisting different tasks is needed. We measured shoulder muscles activity (AD – anterior deltoid and MD – medial deltoid) of seven automotive workers using the SuitX® upper limb exoskeleton while performing different screwing tasks, at different shoulder levels while handling different tools. We found significant muscle activity reduction for 2 of the 4 proposed tasks, suggesting a task-specificity effectiveness. Therefore, it seems to be a viable option to reduce muscle effort in certain tasks.