Table 2.
Muscle volume changes in the medial thigh, posterior thigh and hip
| Group | Baseline | Bed-rest | Recovery | ||||
| 28d (%) | 89d (%) | 13d (%) | 90d (%) | 180d (%) | 360d (%) | ||
| Adductor brevis | |||||||
| Inactive | 164.1 (24.1) | −1.0 (6.0) | −2.5 (7.3) | −0.8 (8.5) | 5.6 (8.9) | 6.0 (7.1)† | 4.9 (7.5)* |
| Flywheel | 186.7 (20.2) | −8.2 (7.6)† | −4.8 (6.8) | −0.4 (6.0) | −0.6 (5.2) | 0.5 (6.5) | −2.4 (7.1) |
| Adductor longus | |||||||
| Inactive | 159.0 (32.5) | −0.7 (11.3) | −7.1 (12.6)* | −0.9 (14.0) | 2.9 (9.3) | 4.5 (10.7) | 5.8 (12.7) |
| Flywheel | 175.8 (20.7) | −1.4 (7.8) | −2.9 (9.1) | −0.9 (9.7) | 3.2 (11.1) | −0.6 (11.5) | −1.3 (9.9) |
| Adductor magnus | |||||||
| Inactive | 585.8 (78.2) | −7.8 (5.4)‡ | −13.0 (6.2)‡ | −4.7 (4.9)‡ | 1.6 (5.6) | 1.4 (5.2) | 3.0 (5.6) |
| Flywheel | 586.6 (62.5) | −3.0 (4.1) | −6.1 (3.8)‡ | −1.2 (3.9) | 2.2 (2.3)* | 1.3 (4.3) | −0.2 (3.8) |
| Gracilis | |||||||
| Inactive | 101.6 (20.3) | 0.2 (5.4) | −2.6 (5.8) | 1.0 (7.0) | 3.5 (6.4) | 3.3 (5.9) | 6.2 (9.9) |
| Flywheel | 115.2 (27.1) | −2.5 (5.0) | −6.8 (8.5)* | 1.6 (7.4) | 3.9 (6.8) | 2.5 (6.1) | 0.2 (5.5) |
| Sartorius | |||||||
| Inactive | 162.3 (24.2) | −5.9 (4.9)‡ | −9.4 (5.9)‡ | −3.8 (5.8)* | 2.3 (6.5) | 3.8 (5.3)* | 5.0 (6.3)* |
| Flywheel | 172.8 (11.4) | −4.3 (3.3)‡ | −9.1 (4.9)‡ | −1.7 (5.4) | 0.8 (4.0) | 4.9 (7.0) | 0.5 (6.7) |
| Biceps femoris long head | |||||||
| Inactive | 190.2 (24.0) | −10.5 (6.4)‡ | −20.0 (7.8)‡ | −10.5 (7.0)‡ | 2.7 (6.9) | 1.7 (4.9) | 2.2 (6.0) |
| Flywheel | 234.1 (31.3) | −11.8 (3.8)‡ | −21.1 (5.2)‡ | −11.7 (5.9)‡ | 0.9 (6.6) | 0.9 (7.2) | 0.5 (7.3) |
| Biceps femoris short head | |||||||
| Inactive | 97.4 (25.0) | −2.8 (7.5) | −6.3 (8.6)† | −0.2 (7.1) | 4.5 (8.5) | 3.0 (7.8) | 3.1 (8.4) |
| Flywheel | 104.7 (14.9) | −4.4 (3.1)‡ | −6.8 (7.6)* | −0.1 (5.9) | −1.1 (5.8) | −0.7 (3.9) | −1.5 (5.1) |
| Semimembranosus | |||||||
| Inactive | 252.6 (43.9) | −10.4 (4.1)‡ | −18.0 (6.3)‡ | −8.4 (6.5)‡ | 2.4 (4.5) | 2.7 (3.7)* | 4.3 (6.0)* |
| Flywheel | 300.5 (50.0) | −10.7 (6.8)‡ | −18.0 (9.0)‡ | −9.3 (7.5)‡ | 1.2 (6.2) | −0.6 (6.5) | 1.4 (4.7) |
| Semitendinosus | |||||||
| Inactive | 182.3 (19.3) | −4.1 (5.6)* | −7.3 (6.9)‡ | −3.6 (6.0)* | 2.2 (5.8) | 2.2 (6.4) | 2.0 (7.6) |
| Flywheel | 189.5 (11.6) | −6.5 (4.5)‡ | −10.6 (3.2)‡ | −7.1 (4.0)‡ | 0.7 (6.3) | −1.1 (5.4) | −2.7 (6.5) |
| Popliteus | |||||||
| Inactive | 21.0 (4.3) | −1.6 (6.3) | −5.1 (10.2) | −0.4 (8.2) | 2.4 (7.4) | −0.7 (6.2) | 1.8 (8.3) |
| Flywheel | 22.1 (3.7) | −2.6 (7.5) | −4.0 (7.8) | 2.6 (6.0) | −3.4 (8.5) | 0.3 (7.5) | −3.6 (5.9) |
| Lower gluteus maximus | |||||||
| Inactive | 535.6 (96.6) | −4.1 (7.4) | −6.9 (8.5)† | −4.5 (6.4)* | 1.6 (7.2) | 0.8 (8.1) | 5.5 (10.9) |
| Flywheel | 590.4 (80.7) | −0.4 (6.1) | −0.5 (6.6) | −0.3 (7.1) | −2.4 (6.6) | −0.8 (5.5) | −3.5 (7.4) |
| Obturator externus | |||||||
| Inactive | 72.6 (10.2) | 3.5 (6.6) | 1.9 (7.8) | 3.5 (8.3) | 8.6 (8.9)† | 7.6 (8.7)† | 6.4 (7.8)† |
| Flywheel | 73.8 (8.2) | −2.8 (7.2) | −0.7 (9.6) | 3.9 (5.7) | 2.4 (8.4) | 0.2 (3.9) | 3.6 (8.0) |
| Obturator internus | |||||||
| Inactive | 57.8 (8.5) | 5.6 (7.8)* | 3.6 (9.4) | 3.3 (9.2) | 3.1 (9.0) | 2.2 (8.9) | −1.0 (9.4) |
| Flywheel | 60.4 (7.1) | 6.1 (6.6)* | 9.4 (5.0)‡ | 9.2 (6.8)† | 3.0 (6.2) | 0.2 (8.6) | 0.3 (7.8) |
| Quadratus femoris | |||||||
| Inactive | 36.1 (9.5) | −8.8 (13.3)* | −13.5 (12.2)‡ | −7.8 (11.5)* | −4.5 (8.2) | 3.9 (9.5) | 4.7 (10.5) |
| Flywheel | 40.0 (6.7) | −7.7 (10.0)* | −9.8 (11.0)* | −1.0 (10.3) | 2.0 (6.4) | 3.7 (8.0) | −2.8 (9.4) |
| Iliopsoas | |||||||
| Inactive | 71.8 (13.1) | −1.0 (11.3) | −5.9 (11.0) | 0.5 (9.5) | −1.3 (9.0) | 0.4 (10.0) | 1.7 (9.7) |
| Flywheel | 74.0 (16.8) | −5.0 (9.3) | −4.3 (9.8) | −2.1 (12.1) | 0.8 (11.8) | 4.6 (11.1) | −1.7 (10.2) |
At baseline, values are mean (SD) muscle volume in cm³. During and after bed-rest, values are mean (SD) percentage change in muscle volume compared with baseline. *: p<0.05; †:p<0.01; ‡: p<0.001 and indicate significance of difference to baseline. All p values are adjusted for false positives via the ‘false discovery rate’ method.