Saskia Baltrusch

246 Chapter 9 the factors mentioned in the previous paragraph, a field study should be done, as an essential step before implementing the device in industry. A context-dependent exoskeleton in the rehabilitation setting would mean an exoskeleton that is individualized to the needs of the patient. Gradual adjustment of support or patient-dependent support could be a way of providing a more individualized exoskeleton. However, finding the optimal support for different users is challenging, as responses to the same device can differ considerably due to physiological and neurological differences between users [15,16]. Furthermore, those responses can change substantially, when adapting to the device [17]. A potential approach to find the optimal support for different users, might be the ‘human in the loop optimization’, a method that allows for optimizing exoskeleton characteristics in real-time and providing a support-pattern, that is customized to the user’s needs [18]. Certainly, this approach would be much more complex for a passive trunk exoskeleton, such as SPEXOR, compared to the ankle exoskeleton used in the study by Zhang et al. (2017) [18]. Still, it would provide an adjustable and self-optimized support, that might improve performance in various patients, suffering from low-back pain. Another implication that can be drawn from the results of this thesis is the need for assessing the long-term effects of the passive SPEXOR exoskeleton. The current thesis only addressed instantaneous effects on experienced load and performance. How these affect prevention and/or development of low-back pain remains to be established. Concerns mentioned by the healthcare professionals and patients, such as loss of muscle strength or overloading once the device is taken off, could be addressed in such a study. Also, given the fact that pain relief is such an important factor for low-back pain patients, as described earlier, assessing pain levels over a longer period of time when using the exoskeleton would be of added value. Conclusion This thesis investigated the potential of using a passive trunk exoskeleton (SPEXOR) for low-back pain prevention and vocational reintegration and gives insight into factors that can influence the usability and acceptability of an exoskeleton. It was shown that exoskeletons are of benefit for lifting and static postures, that involve mechanical loading on the back. Employees feel