Saskia Baltrusch

142 Chapter 5 4.3 Functional Testing The users impression of the device as assessed in the Users Impression Questionnaire show very good results for the categories “ROM” and “Interference with tasks” and good to moderate values for the categories “Reduction of back loading,” “Support of tasks,” and “Overall impression” (Table 2). We contrasted our results with the results of the study from Baltrusch et al. (2018) [26], to indicate improvements in the prototype compared to the Laevo device, based on user’s impressions. Table 2: Users impression assessed by VAS scales: Numbers in brackets indicate the results of the study measured with Laevo in the study of Baltrusch et al. (2018) [26]. The Perceived task difficulty decreased when wearing the exoskeleton in one of the tasks to assess the supportive character of the device and did not change in the other one. Tasks to assess the extent of restricted hip flexion showed no change or a slight increase in perceived task difficulty when wearing the prototype. Participants perceived the range of motion tasks as slightly more difficult, with the exception of forward bending, which was perceived easier to perform with the exoskeleton (Figure 12A). We again contrasted these results to the values of Baltrusch et al. (2018) [26] assessed when testing the Laevo device (Figure 12B), by comparing the median change in perceived task difficulty. Hence, values above zero indicate support by the device, whereas values below zero indicate hindrance by the device when performing the task. With regard to discomfort levels, the physical user interface shows promising results. Participants reported low discomfort, ranging from 0.6 cm on the VAS scale for wide stance up to 4.4 cm for walking. Problems that were still mentioned are touching of the leg pads during walking, friction on the side of the neck and pressure on the hips.