Saskia Baltrusch

235 Chapter 9 guarded movement. Further, they criticized that an exoskeleton only focuses on the mechanical risk factor for low-back pain, whereas chronic low-back pain has a variety of causes. In contrast, patients considered passive exoskeletons as useful support in their rehabilitation, provided the suggested features could be incorporated. Thus, the potential application in the field of rehabilitation is not without debate, and therefore application in the domain of prevention in the occupational field seems more likely at the current moment. Importantly, this study revealed, that an adequate implementation strategy and communication between the user and the professional is essential when aiming to implement an exoskeleton. Part 2: What is the effect of the exoskeleton on functional performance, user satisfaction and aerobic loading? The second part of this thesis focused on evaluating the functional effects of a trunk exoskeleton. A test battery was developed to evaluate both, the potential positive effects in reducing low back load, but also potential negative effects in decreasing functional performance and to assess usability of the exoskeleton. Given the variety of working tasks that can be found in various physically demanding jobs, the test battery consists of work-related daily activity tasks that had to be performed with and without the exoskeleton. In each task, functional performance was assessed based on objective outcome measures and subjectively in terms of perceived task difficulty, discomfort and user satisfaction. In Chapter 3, this test battery was used to assess how a commercially available device, “the Laevo exoskeleton”, affects functional performance and user satisfaction. The aim was to assess potential limitations and to formulate design requirements for the SPEXOR exoskeleton. The results revealed a positive effect of the Laevo exoskeleton in reducing low-back load in static forward bending. In carrying and non-load handling tasks that involved substantial trunk and hip flexion without trunk inclination, objective and subjective performance decreased when wearing this exoskeleton. In Chapter 4 , I assessed the effect of wearing the Laevo exoskeleton on metabolic cost. The exoskeleton seems to effectively unload the user during lifting, by decreasing metabolic cost by 17%. It may hence reduce the development of fatigue and low-back pain risk for this specific task. However, during walking, a task that requires hip flexion, metabolic cost 9