Table 3 Group comparison of change from baseline in thicknesses of rectus abdominis, diaphragm, combined lateral abdominal muscle and each individual muscle by assessment session. Data are summarised as mean ± SD (n). Active versus control analysed using a least square mean difference based on a mixed effects model for repeated measures. p values based on a mixed effects model for repeated measures. NE not estimable
Assessment session | Active | Control | Active–control | p value |
|---|---|---|---|---|
Change from baseline in rectus abdominis thickness (mm) by assessment session | ||||
 Day 3 | 0.33 ± 0.909 (6) | − 0.10 ± 0.451 (9) | 0.61 (− 0.13, 1.35) | 0.099 |
 Day 5 | − 0.03 ± 0.871 (5) | 0.29 ± 0.759 (6) | − 0.11 (− 0.96, 0.74) | 0.785 |
 Day 12 | 0.68 ± 0.165 (2) | 0.35 ± 0.453 (4) | 0.09 (−1.07, 1.25) | 0.877 |
 Day 19 | NE | 1.22 ± 1.167 (2) | NE | NE |
 Day 26 | NE | 1.37 ± 0.813 (2) | NE | NE |
 Day 33 | NE | 2.90 ± 0.071 (2) | NE | NE |
Change from baseline in diaphragm thickness (mm) by assessment session | ||||
 Day 3 | − 0.17 ± 0.274 (7) | − 0.18 ± 0.207 (6) | 0.06 (− 0.23, 0.36) | 0.652 |
 Day 5 | − 0.11 ± 0.404 (7) | − 0.18 ± 0.225 (4) | − 0.04 (− 0.38, 0.30) | 0.794 |
 Day 12 | − 0.13 ± 0.305 (4) | − 0.03 ± 0.336 (4) | − 0.07 (− 0.44, 0.31) | 0.698 |
 Day 19 | NE | 0.30 (1) | NE | NE |
 Day 26 | NE | − 0.72 (1) | NE | NE |
 Day 33 | NE | 0.08 (1) | NE | NE |
Change from baseline in combined lateral abdominal muscle thickness (mm) by assessment session | ||||
 Day 3 | 2.51 ± 2.535 (4) | − 0.01 ± 2.113 (9) | 3.05 (− 0.35, 6.44) | 0.074 |
 Day 5 | 0.63 ± 0.701 (4) | 0.28 ± 2.186 (7) | 1.23 (− 2.29, 4.75) | 0.463 |
 Day 12 | 1.55 (1) | − 0.88 ± 2.902 (5) | 3.66 (− 1.96, 9.28) | 0.183 |
 Day 19 | NE | 0.22 ± 3.005 (2) | NE | NE |
 Day 26 | NE | 4.12 ± 4.419 (2) | NE | NE |
 Day 33 | NE | 3.75 (1) | NE | NE |
Change from baseline in external oblique thickness (mm) by assessment session | ||||
 Day 3 | 0.52 ± 0.685 (4) | − 0.05 ± 1.153 (9) | 1.08 (− 0.07, 2.23) | 0.064 |
 Day 5 | 0.09 ± 0.954 (4) | − 0.35 ± 0.881 (7) | 0.95 (− 0.24, 2.13) | 0.108 |
 Day 12 | − 1.14 (1) | − 0.49 ± 0.248 (5) | − 0.68 (− 2.57, 1.20) | 0.450 |
 Day 19 | NE | 0.35 ± 0.071 (2) | NE | NE |
 Day 26 | NE | 0.77 ± 0.177 (2) | NE | NE |
 Day 33 | NE | 2.20 (1) | NE | NE |
Change from baseline in internal oblique thickness (mm) by assessment session | ||||
 Day 3 | 0.79 ± 1.718 (4) | 0.13 ± 0.936 (9) | 1.08 (− 1.24, 3.40) | 0.335 |
 Day 5 | − 0.43 ± 1.040 (4) | 0.58 ± 1.694 (7) | − 0.37 (− 2.74, 2.01) | 0.746 |
 Day 12 | 0.09 (1) | − 0.05 ± 2.385 (5) | 1.61 (− 2.16, 5.39) | 0.375 |
 Day 19 | NE | 0.50 ± 1.838 (2) | NE | NE |
 Day 26 | NE | 2.33 ± 2.722 (2) | NE | NE |
 Day 33 | NE | 1.75 (1) | NE | NE |
Change from baseline in transversus abdominis thickness (mm) by assessment session | ||||
 Day 3 | 0.85 ± 1.065 (4) | − 0.12 ± 0.849 (9) | 1.04 (0.10, 1.98) | 0.032 |
 Day 5 | 0.56 ± 0.775 (4) | 0.10 ± 0.532 (7) | 0.68 (− 0.32, 1.68) | 0.168 |
 Day 12 | 1.74 (1) | − 0.11 ± 0.318 (5) | 2.28 (0.50, 4.06) | 0.016 |
 Day 19 | NE | − 0.18 ± 0.742 (2) | NE | NE |
 Day 26 | NE | 0.78 ± 1.025 (2) | NE | NE |
 Day 33 | NE | 0.35 (1) | NE | NE |