Table 1.
Changes in lumbar intervertebral foramen dimensions at different levels from neutral to hyperextension supine position (mean ± SD)
| Location | Neutral | Hyper‐extension | Change | P | |
|---|---|---|---|---|---|
| Absolute value | % | ||||
| L1‐2 | |||||
| Area (mm2) | 162.4 ± 26.4 | 130.2 ± 26.8 | 32.2 ± 10.6 | 20.1 ± 6.4 | <0.01 |
| Height (mm) | 19.6 ± 1.9 | 17.7 ± 1.8 | 1.9 ± 0.8 | 9.5 ± 3.7 | <0.01 |
| Width (mm) | 10.4 ± 1.5 | 9.0 ± 1.5 | 1.3 ± 0.8 | 12.8 ± 7.4 | <0.01 |
| L2‐3 | |||||
| Area (mm2) | 170.8 ± 26.4 | 132.3 ± 24.6 | 38.5 ± 12.3 | 22.6 ± 6.6 | <0.01 |
| Height (mm) | 20.4 ± 2.1 | 18.3 ± 1.9 | 2.2 ± 0.9 | 10.5 ± 3.9 | <0.01 |
| Width (mm) | 10.1 ± 1.2 | 8.7 ± 1.2 | 1.5 ± 0.7 | 14.5 ± 7.9 | <0.01 |
| L3‐4 | |||||
| Area (mm2) | 158.0 ± 25.2 | 126.0 ± 21.2 | 32.0 ± 14.5 | 19.9 ± 7.7 | <0.01 |
| Height (mm) | 19.6 ± 1.9 | 17.8 ± 1.7 | 1.9 ± 0.8 | 9.5 ± 4.0 | <0.01 |
| Width (mm) | 9.8 ± 1.3 | 8.5 ± 1.2 | 1.3 ± 0.9 | 13.0 ± 8.8 | <0.01 |
| L4‐5 | |||||
| Area (mm2) | 143.4 ± 16.8 | 117.7 ± 18.3 | 25.7 ± 10.3 | 18.1 ± 7.1 | <0.01 |
| Height (mm) | 18.6 ± 1.8 | 16.8 ± 1.2 | 1.8 ± 0.8 | 9.6 ± 4.3 | <0.01 |
| Width (mm) | 9.5 ± 1.0 | 8.5 ± 1.0 | 1.0 ± 0.6 | 10.4 ± 6.2 | <0.01 |
| L5–S1 | |||||
| Area (mm2) | 124.3 ± 20.7 | 109.0 ± 16.6 | 15.3 ± 6.8 | 12.0 ± 4.5 | <0.01 |
| Height (mm) | 15.5 ± 1.5 | 14.5 ± 1.5 | 1.0 ± 0.6 | 6.1 ± 3.8 | <0.01 |
| Width (mm) | 10.1 ± 1.4 | 9.2 ± 1.2 | 0.9 ± 0.7 | 8.4 ± 6.4 | <0.01 |