Saskia Baltrusch

155 Chapter 6 1 Introduction In spite of extensive research efforts, low-back pain continues to be one of the most prevalent and costly health problems around the globe [1]. As an industrial problem, it represents a high economic burden by affecting 75-85% of workers at some point in their lifetime [2], leading to high numbers of lost working days [3]. The causes of low-back pain (LBP) are known to be multifactorial [4] including physical occupational risk factors, such as heavy physical work, frequent lifting, forward bending, awkward postures and manual materials handling [5-7]. By implementing ergonomic interventions and regulations, companies strive to prevent work-related low-back pain. However, the workplace, being a complex and dynamic environment, encompasses high variability in tasks and movements, which makes it hard to introduce robust preventive strategies. Redesigning the working environment would be the best approach to avoid risk factors. Unfortunately, a modification of workplaces is not always feasible. It might lead to inefficient working or comes at high costs. Moreover, currently available assistive off-body devices, like hoists and palletisers, are often not used since employees perceive them to be disturbing their work flow. In the last 20 years, body worn assistive devices (exoskeletons) have been introduced in the industrial setting, to deal with the problems encountered with off-body lifting aids. A review by de Looze et al. (2016) [8] showed that passive exoskeletons have the potential to considerably reduce occupational risk factors associated with developing low-back pain. Specifically, these exoskeletons decrease spinal loading during lifting, bending, and static holding tasks [9-13] without the need for workers to adapt their work flow. Still, there are multiple drawbacks of the current designs of passive exoskeletons. Several studies have reported substantial discomfort levels when wearing an exoskeleton [10,14,15], which reduce the feasibility of workers wearing it during a whole working day. Moreover, we observed that a currently commercially available exoskeleton had limited versatility [14]. This restricts the application of such a device to stereotypical tasks, which is in contrast to the wide range of work tasks and work environments that can be found in many load-handling professions. It was also shown that restrictions of the device increased metabolic costs when 6