Analyse des Einflusses von passiven Exoskeletten für Überkopftätigkeiten auf die Haltezeiten von Werkzeugen, die lokale physiologische Beanspruchung und den Bewegungsraum der oberen Extremitäten

Abstract

Analysis of the influence of passive exoskeletons for overhead activities on tool holding times, local physiological strain and the range of motion of the upper limbs Objectives: This paper presents three laboratory studies on the second stage of the Institute of Ergonomics (Institut für Arbeitswissenschaft, IAD) concept for the application of passive exoskeletons in practice. An analysis is conducted on objective and subjective outcomes in relation to changes in loading/strain, holding times and range of motion when using three selected exoskeletons for overhead activities. Methods: Surface electromyography (EMG) is used to determine physiological muscular strain. Relevant muscles in the arm-shoulder area and in the back are selected for this purpose on the basis of reference literature and preliminary studies. Subjective outcomes concerning the discomfort of the test subjects during overhead activities with and without exoskeleton are recorded by means of the Corlett-Bishop scale. The neutral-zero-method was used to determine the range of motion. Results: The IAD concept for the analysis and evaluation of physical stress and strain when using passive exoskeletons in overhead work in the laboratory and in practice is described. On the basis of the laboratory studies carried out, it was found that muscular strain is significantly reduced when using the analysed exoskeletons in the arm-shoulder system, but increases at the same time in the back. Similarly, holding times were shown to be longer depending on the holding position. The range of movement in the area of overhead work is not restricted by the exoskeleton. In the case of free movements, it could be shown that the arms were held above shoulder height to an increasing degree when using an exoskeleton. Conclusions: The three studies carried out provide information on changes in stress and strain, holding times and range of motion when using three passive exoskeletons for overhead activities. Implications are derived for the use of passive exoskeletons in practice. The aim should be to produce further findings from practical field studies with working persons as well as with adapted ergonomic analysis methods. Keywords: passive exoskeletons – overhead work – strain – holding time – range of motion – surface electromyography (EMG)