Collected SWV data from volunteer subjects, including interspinous distances in physiologic extension and flexion, percent increase between the positions, and SWV in both positions.
| Level | Subjects, N | Extension Distance, cm | Flexion Distance, cm | % Increase | Extension SWV, m/s | Flexion SWV, m/s | % Increase |
| T10-T11 | 7 | 1.34 ± 0.12 | 1.48 ± 0.28 | 11 | 2.50 ± 0.97 | 3.28 ± 1.20 | 31 |
| T12-L1 | 9 | 1.02 ± 0.32 | 1.61 ± 0.30 | 58 | 1.71 ± 0.59 | 4.08 ± 1.13 | 139 |
| L2-L3 | 9 | 0.96 ± 0.27 | 1.86 ± 0.34 | 93 | 1.70 ± 0.36 | 5.01 ± 1.58 | 195 |
| L4-L5 | 9 | 0.84 ± 0.31 | 1.91 ± 0.46 | 127 | 1.53 ± 0.37 | 4.59 ± 2.31 | 200 |
Abbreviation: SWV, shear wave velocity.