Evaluation of Physiological Costs Using Standardized Analysis Methods During Simulated Overhead Work with and Without Exoskeleton

Abstract

In spite of Industry 4.0 and the resulting increased automation of work processes, assembly activities in constrained postures, e.g. overhead work that cannot be performed by robots are still necessary. Here, the passive upper body exoskeleton Airframe® made by Levitate is intended to provide support for overhead work. Thus, it reduces the risk of musculoskeletal disorders of the shoulders, neck and upper back. The aim of this paper is to evaluate the physiological advantages and disadvantages of an exoskeleton during simulated overhead work under laboratory conditions. Twenty subjects, aged between 18 and 64 years, participated in the laboratory study. To determine the physiological costs under variable test conditions, the muscular activity of the muscles trapezius pars descendens, deltoideus pars clavicularis, deltoideus pars acromialis and latissimus dorsi (bilateral in each case) were continuously recorded by surface electromyography. In standardized test sequences, the test persons were asked to perform three partial tests with and without the exoskeleton. This procedure included plugging and screwing activities (by hand and using an electric screwdriver). After each run-through, the current physical condition was assessed using a simple body chart. In addition, a short survey on subjective perception was conducted after each partial test. The results show that the use of the exoskeleton Airframe® particularly favors a reduced muscular activity of the shoulder and neck muscles. The test person’s subjective stress sensation also showed that the use of the exoskeleton had a positive effect on most activities, especially in the shoulder and neck area.