## 3 Results
### Tissue Oxygen  
TSI\({}_{\text{Base}}\) averaged 57.2 (5.7) % for all test conditions before occlusion was applied or pHMI was closed. There was no significant difference in TSI\({}_{\text{Base}}\) for all test conditions. Table 3 lists TSI\({}_{\text{Base}}\) for each test condition. Figure 7A shows the mean TSI trajectories of the test conditions in resting posture with closed exoskeleton interfaces against TSI trajectories of the standardized Vascular Occlusion Tests. Figure 7B shows the mean TSI trajectories of the dynamic exoskeleton conditions against the standard Vascular Occlusion Test trajectories. The downslope of TSI (TSI\({}_{\text{Slope1}}\)) averaged \(-\)2.1 (1.4) %/min over all resting conditions. There was no significant difference between all resting conditions in TSI\({}_{\text{Slope1}}\); see Table 4. In dynamic test conditions, TSI\({}_{\text{Slope1}}\) averaged \(-\)7.3 (4.1) %/min over all exoskeleton conditions. The TSI\({}_{\text{Slope1}}\) values for each dynamic condition can be found in Table 3. The multifactorial ANOVA revealed a significant difference for TSI\({}_{\text{Slope1}}\) between resting and dynamic test conditions (movement), whereas no significant difference was found for the exoskeleton design and the interaction between pHMI design and movement; compare Table 5. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline  & \multicolumn{4}{c}{**Resting Posture**} & \multicolumn{4}{c}{**Dynamic Movement**} \\  & **Art. Occ.** & **Ven. Occ.** & **Lucy** & **Paexo** & **Skelex** & **Lucy** & **Paexo** & **Skelex** \\ \hline Mean pressure [mmHg] & 200.1 (1.8) & 52.6 (0.4) & 16.1 (6.5) & 38.3 (14.3) & 23.8 (11.8) & 24.3 (12.9) & 55.7 (21.4) & 39.3 (10.7) \\ TSI\({}_{\text{Base}}\) [\%] & 58.3 (3.1) & 60.7 (2.8) & 55.8 (8.0) & 57.3 (6.3) & 56.4 (5.8) & 56.4 (6.9) & 57.2 (5.3) & 56.4 (5.9) \\ TSI\({}_{\text{Slope1}}\) [\%/min] & \(-\)2.1 (1.1) & \(-\)1.5 (0.5) & \(-\)1.6 (1.0) & \(-\)2.5 (2.2) & \(-\)2.7 (1.5) & \(-\)5.9 (3.6) & \(-\)9.0 (4.5) & \(-\)7.0 (4.3) \\ TSI\({}_{\text{Slope2}}\) [\%/min] & 35.6 (18.4) & 6.5 (5.7) & 6.7 (5.9) & 7.7 (5.9) & 7.0 (5.5) & 46.1 (33.3) & 58.7 (25.4) & 51.6 (36.8) \\ TSI\({}_{\text{Overshoot}}\) [\%] & 9.8 (4.2) & \(-\)1.2 (2.7) & 1.6 (2.7) & 1.4 (1.7) & 1.4 (2.4) & 11.8 (6.4) & 9.6 (5.7) & 10.3 (5.8) \\ \hline \end{tabular}
\end{table} 
Table 3: Descriptive data of the measurements (mean (standard deviation)). Figure 7: Mean TSI curves of VOTs and resting posture conditions (**A**) and dynamic conditions (**B**). The upslope of the oxygen level (TSI\({}_{\text{Slope2}}\)) after reopening the tourniquet or pHMI averaged at 35.6 (18.4) %/min for arterial occlusion, at 6.5 (5.7) %/min for venous occlusion, at 6.7 (5.9) %/min for Lucy, at 7.7 (5.9) %/min for Paexo Shoulder, and at 7.0 (5.5) %/min for Skelex 360 in resting condition; see Table 3. Repeated-measures ANOVA for the resting conditions revealed a difference between arterial occlusion and venous occlusion as well as between arterial occlusion and Paexo Shoulder; see Table 4. There was no difference between venous occlusions and the exoskeleton conditions as well as among the exoskeletons. In dynamic conditions, TSI\({}_{\text{Slope2}}\) averaged at 51.9 (31.4) %/min for all exoskeleton conditions. The multifactorial ANOVA revealed a significant difference for movement but not for pHMI design or the interaction of the two factors for the dependent variable TSI\({}_{\text{Slope2}}\); see Table 5.