Average distances, in cm, between spinous processes at interspaces for 5 cadavers (n = 5) in physiologic extension and flexion positions, with relative percent increases. The designated percent increase was calculated by a paired methodology whereby the increase was calculated in a single ligament moving from flexion to extension prior to being averaged.
| Level | Extension, Mean ± SD | Flexion, Mean ± SD | Increase %, Mean ± SD |
| T9-T10 | 1.48 ± 0.22 | 1.34 ± 0.30 | 2.72 ± 10.11 |
| T10-T11 | 1.37 ± 0.38 | 1.38 ± 0.22 | 8.16 ± 17.38 |
| T11-T12 | 1.91 ± 0.30 | 1.89 ± 0.52 | 6.34 ± 12.83 |
| T12-L1 | 1.45 ± 0.29 | 1.80 ± 0.28 | 26.86 ± 18.12 |
| L1-L2 | 1.44 ± 0.33 | 1.68 ± 0.21 | 19.07 ± 16.63 |
| L2-L3 | 1.22 ± 0.26 | 1.89 ± 0.32 | 58.75 ± 25.11 |
| L3-L4 | 1.38 ± 0.59 | 2.06 ± 0.24 | 63.36 ± 41.88 |
| L4-L5 | 1.30 ± 0.50 | 1.81 ± 0.54 | 45.74 ± 37.25 |
| L5-S1 | 1.29 ± 0.66 | 1.72 ± 0.76 | 40.61 ± 28.13 |