Passive Stiffness Values Average ± St.Deviation (N/mm) | AXIAL loading | ||||
---|---|---|---|---|---|
 |  | negative direction | positive direction | both directions | overall |
TWIN RING module | ± 3 mm | 67.2 ± 0.2 | 69.1 ± 0.2 | 68.2 ± 1.1 | 71.4 ± 3.0 |
 | ± 5 mm | 70.2 ± 0.2 | 75.1 ± 0.1 | 72.7 ± 2.6 |  |
 | ± 7 mm | 75.3 ± 0.2 | 71.2 ± 0.2 | 73.2 ± 2.1 |  |
SINGLE RING module | ± 3 mm | 92.3 ± 0.2 | 92.2 ± 0.4 | 92.2 ± 0.3 | 94.4 ± 2.9 |
 | ± 5 mm | 98.0 ± 0.2 | 95.1 ± 0.2 | 96.6 ± 1.5 |  |
 | ± 7 mm | 98.0 ± 0.2 | 91.1 ± 0.3 | 94.5 ± 3.6 |  |