Saskia Baltrusch

166 Chapter 6 In the static postural tolerance tasks, the exoskeleton decreased local discomfort significantly in the abdomen (p=0.003), low back (p=0.000), upper back (p=0.03) and hamstrings (p= 0.02) during static forward bending and in the low (p=0.008) and upper back (p=0.02) during 3 point kneeling (Figure 5). Subgroup analysis for static forward bending revealed significantly decreased local discomfort in the low-back pain group, in abdomen (p=0.04), low back (p=0.007), thighs (p=0.04) and hamstrings (p=0.03). For the healthy group, a significant decrease in the low back (p=0.006) was found. For 3 point kneeling, the low-back pain group showed decreased local discomfort in upper back (p=0.02) and low back (p=0.002). Figure 5a: Boxplots of change in local discomfort in different body parts for the static postural tolerance tasks forward bending and 3 point kneeling. *Significant change in local discomfort between exoskeleton (with) and control condition (without). Note that in this figure an increase represents a negative effect and a decrease a positive effect. Figure 5b: Difference in local discomfort between control and exo condition in the subgroups healthy participants compared to participants with low-back pain. *Significant change in local discomfort between exoskeleton (with) and control condition (without) in the respective group. As shown in Figure 6, general discomfort of the exoskeleton ranged from 0 to 9 (0=no discomfort, 10=maximum discomfort), with highest mean values for walking, with a median value of (interquartile range): 2.8 (1.6-4.9) and lowest values for carrying: 0.3 (0.1-1.0).