Table 1. Ranges of motion (ROM) and neutral zones (NZ) of the thoracic spine (T1-T12) are shown for the single specimen conditions (IC = intact condition, W/o IM = without intercostal muscles, MST = after median sternotomy, W/o ARC = without anterior rib cage, W/o RH 6–8 = without 6th-8th right rib head, W/o RH = without all rib heads) in the single motion planes for 2 Nm pure bending moment (n = 6).
| Specimen condition | Flexion/extension | Lateral bending | Axial rotation | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| M ± SD (°) | PC (%) | IC (%) | M ± SD (°) | PC (%) | IC (%) | M ± SD (°) | PC (%) | IC (%) | ||
| IC | ROM | 10.5 ± 4.0 | 14.9 ± 3.9 | 20.4 ± 7.4 | ||||||
| NZ | 7.9 ± 3.4 | 11.8 ± 4.3 | 2.4 ± 1.1 | |||||||
| W/o IM | ROM | 11.8 ± 5.0 | + 11.7 a | 18.3 ± 5.4 | + 22.4 *b | 25.0 ± 9.5 | + 22.6 *b | |||
| NZ | 8.9 ± 4.0 | + 12.6 *a | 15.3 ± 5.6 | + 30.0 *b | 3.0 ± 1.3 | + 21.7 *a | ||||
| MST | ROM | 13.2 ± 5.6 | + 11.9 *a | + 25.0 *b | 19.3 ± 5.2 | + 5.7 a | + 29.3 *c | 30.5 ± 11.1 | + 21.9 *b | + 49.4 *c |
| NZ | 9.2 ± 4.1 | + 3.2 | + 16.2 *a | 16.3 ± 5.9 | + 6.8 a | + 38.8 *c | 4.1 ± 2.0 | + 37.1 b | + 66.9 *c | |
| W/o ARC | ROM | 16.0 ± 6.6 | + 21.1 *b | + 52.2 *c | 21.2 ± 5.7 | + 9.8 *a | + 42.0 *c | 39.7 ± 13.4 | + 30.1 *c | + 94.4 *c# |
| NZ | 11.5 ± 5.4 | + 25.3 *b | + 45.6 *c | 18.1 ± 6.1 | + 10.9 *a | + 54.0 *c | 7.0 ± 3.3 | + 72.5 *c | + 187.8 *c# | |
| W/o RH 6–8 | ROM | 17.0 ± 7.5 | + 6.3 | + 6.3 | 22.3 ± 5.7 | + 5.3 a | + 49.6 *c# | 44.3 ± 15.2 | + 11.7 *a | + 117.1 *c# |
| NZ | 12.5 ± 6.4 | + 8.9 | + 8.9 | 19.4 ± 6.1 | + 7.3 a | + 65.2 *c# | 8.3 ± 3.9 | + 18.5 a | + 240.9 *c# | |
| W/o RH | ROM | 16.9 ± 7.3 | - 0.6 | - 0.6 | 23.6 ± 6.4 | + 5.7 a | + 58.0 *c# | 46.9 ± 16.1 | + 5.8 * | + 129.7 *c# |
| NZ | 11.7 ± 5.9 | - 6.3 | - 6.3 | 20.6 ± 7.0 | + 6.3 a | + 75.5 *c# | 8.6 ± 4.6 | + 4.1 a | + 254.9 *c# | |
M = mean, SD = standard deviation, PC = variation compared to previous condition, IC = variation compared to intact condition
* p < 0.05
a small effect (0.2 < d < 0.5
b mean effect (0.5 < d < 0.8)
c strong effect (d > 0.8)
# high power (1-β > 0.8)