Muscle volume changes in the lower leg, anterior thigh
| Group | Baseline | Bed-rest | Recovery | ||||
| 28 days (%) | 89 days (%) | 13 days (%) | 90 days (%) | 180 days (%) | 360d (%) | ||
| Anterior tibial muscles | |||||||
| Inactive | 252.1 (24.9) | −7.0 (4.0)‡ | −13.6 (4.9)‡ | −5.1 (3.9)‡ | −0.3 (3.9) | 0.1 (3.9) | 0.4 (4.7) |
| Flywheel | 246.9 (11.8) | −5.1 (4.0)‡ | −11.2 (4.0)‡ | −3.0 (4.6) | 0.5 (4.5) | 1.2 (4.2) | 0.4 (4.5) |
| Flexor digitorum with tibialis posterior | |||||||
| Inactive | 136.6 (25.3) | −11.4 (7.4)‡ | −19.0 (10.4)‡ | −7.3 (6.7)‡ | 1.8 (5.4) | 0.5 (4.2) | 0.9 (4.0) |
| Flywheel | 133.5 (28.5) | −7.1 (6.4)† | −13.0 (7.9)‡ | −6.0 (7.2)* | −1.2 (5.0) | −0.5 (4.6) | 1.0 (5.1) |
| Flexor hallucis longus | |||||||
| Inactive | 80.2 (13.4) | −9.5 (7.0)‡ | −19.6 (8.9)‡ | −14.7 (9.8)‡ | 0.0 (6.5) | 1.8 (7.5) | 2.1 (9.0) |
| Flywheel | 78.3 (8.7) | −8.8 (9.8)* | −15.5 (8.4)‡ | −10.1 (8.4)‡ | −4.8 (7.1) | −2.9 (8.6) | −2.2 (9.3) |
| Lateral gastrocnemius | |||||||
| Inactive | 132.6 (20.7) | −10.7 (10.3)‡ | −23.3 (13.0)‡ | −11.8 (11.6)‡ | 2.6 (9.6) | 1.1 (10.1) | 3.0 (10.5) |
| Flywheel | 140.2 (15.2) | −4.0 (8.4)) | −12.8 (10.7)‡ | −7.5 (9.8)* | 2.3 (8.4) | −0.8 (7.0) | −1.4 (8.2) |
| Medial gastrocnemius | |||||||
| Inactive | 222.1 (40.6) | −15.6 (7.6)‡ | −28.0 (12.3)‡ | −7.6 (8.4)‡ | 2.7 (6.4) | 2.5 (4.8) | 3.9 (6.0)* |
| Flywheel | 235.2 (30.6) | −5.6 (5.2)† | −13.3 (7.3)‡ | −5.1 (6.6)* | 1.7 (4.0) | 0.9 (3.2) | 0.0 (3.0) |
| Peroneals | |||||||
| Inactive | 136.9 (29.0) | −12.1 (6.4)‡ | −22.5 (11.8)‡ | −12.8 (7.7)‡ | −0.1 (4.6) | 0.7 (4.2) | 1.6 (4.9) |
| Flywheel | 140.9 (29.2) | −10.3 (4.7)‡ | −18.4 (6.3)‡ | −9.0 (6.0)‡ | 0.1 (6.7) | −2.0 (8.1) | −0.5 (7.9) |
| Soleus | |||||||
| Inactive | 449.4 (61.0) | −15.6 (6.1)‡ | −28.6 (8.5)‡ | −5.5 (6.1)‡ | 2.4 (4.6) | 3.9 (3.2)‡ | 4.3 (5.0)† |
| Fly-wheel | 496.4 (64.5) | −10.6 (3.0)‡ | −19.9 (4.5)‡ | −5.5 (4.7)† | 1.3 (3.8) | 0.7 (4.5) | 1.2 (3.5) |
| Vasti | |||||||
| Inactive | 1688.8 (203.7) | −12.1 (6.0)‡ | −20.3 (7.3)‡ | −10.1 (6.7)‡ | 0.9 (7.5) | 1.5 (6.8) | 3.1 (8.5) |
| Flywheel | 1670.2 (115.0) | −1.5 (4.3) | −3.8 (5.8) | −0.5 (6.1) | 1.6 (2.1) | 1.0 (3.2) | −0.5 (2.4) |
| Rectus femoris | |||||||
| Inactive | 259.3 (33.0) | −3.6 (5.3)* | −7.9 (6.2)‡ | −4.2 (6.2)* | −0.8 (6.0) | −0.1 (5.4) | 1.0 (6.9) |
| Flywheel | 285.2 (37.3) | −0.2 (3.5) | −2.7 (3.7) | 0.0 (3.9) | 0.0 (3.8) | 2.8 (10.4) | 0.7 (5.4) |
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.