Objectives: Despite the increasing trend of automation and mechanization in the industry, many workers are exposed to high physical workloads, repetitive motions, and unusual body postures. In this regard, assistive technology (AT) is a relatively new and practical solution. This study was conducted to design an assistive arm according to ergonomic principles and investigate its effect on the electrical activity of shoulder muscles.
Methods: This research was fundamental in its approach, using an experimental intervention method. The investigated samples included students studying in the Tabriz University of Medical Sciences, Faculty of Health in 2021, of which 12 participated in the study, half of whom were female and half were male. A prototype of a passive assistive arm was first designed. The electrical activity of muscles was then evaluated at two work heights and two tasks in a simulated workstation with and without the use of an assist arm. The data were analyzed at a significance level of 0.05 using SPSS26 software.
Results: The designed assistive arm reduced the electrical activity of the muscles in the tested heights and tasks, and among the six investigated muscles, the activity of the trapezius and anterior deltoid muscles decreased the most.
Conclusion: According to the results, the designed assistive arm reduces the electrical activity of the shoulder muscles and differentially affects different tasks and work heights. The results generally indicate that the use of an assistive arm can be an effective intervention for overhead tasks.