Table 4 Shear forces in the pre- and postoperative conditions for the upright standing posture (left) and forward flexed posture (right) (Fig. 3). P values for non-parametric paired test between pre- and postoperative values (Wilcoxon matched-pairs signed rank). Δ(abs) is the group average of the difference in shear force magnitude between the pre- and postoperative conditions (Fig. 4)
SHEAR | Upright standing posture | 30° forward flexion posture | |||||||
|---|---|---|---|---|---|---|---|---|---|
preop [N] | postop [N] | p | Δ(abs) | preop [N] | postop [N] | p | Δ(abs) | ||
CTRL group | T12/L1 | − 145 | − 116 | 0.021 | - 29.0 | −63 | −49 | 0.284 | - 7.7 |
L1/2 | − 89 | −76 | 0.196 | −12.5 | −29 | −26 | 0.966 | - 0.1 | |
L2/3 | −34 | −32 | 0.551 | - 2.6 | 48 | 32 | 0.004 | - 8.1 | |
L3/4 | 30 | 34 | 0.417 | - 4.6 | 76 | 37 | < 0.0001 | - 38.4 | |
L5/S1 | 309 | 302 | 0.610 | - 6.9 | 401 | 403 | 0.966 | - 8.7 | |
ASD group | T12/L1 | − 180 | − 155 | 0.044 | - 24.4 | −93 | −78 | 0.430 | - 8.0 |
L1/2 | −101 | −90 | 0.246 | - 9.5 | −37 | −31 | 0.870 | - 11.7 | |
L2/3 | −41 | −36 | 0.498 | - 4.9 | 43 | 32 | 0.064 | - 11.6 | |
L3/4 | 39 | 44 | 0.246 | + 3.9 | 90 | 49 | < 0.0001 | - 39.5 | |
L5/S1 | 356 | 348 | 0.189 | - 8.6 | 445 | 436 | 0.409 | + 2.0 | |