Table 3 Change of safety condition caused by the change of shapes under the 50 N indentation force
| Shape | Maximum shear stress (kPa) | Endurance time (s) |
|---|---|---|
| Gradient (large) | 36.8 | 453 |
| Actual human shape | 33.9 | 676 |
| Gradient (small) | 29.5 | \(\text{1.32 } \times \text{10 }^{\text{3 }}\) |