Table 5.
Mechanical properties in femora and tibiae. Values are means (±SEM).
| 1-Week | 2-Week | 4-Week | 8-Week | |||||
|---|---|---|---|---|---|---|---|---|
| L1 | C1 | L2 | C2 | L4 | C4 | L8 | C8 | |
| Femur | n=12 | n=12 | n=12 | n=11 | n=12 | n=12 | n=12 | n=12 |
| YL (N) | 82.4 (1.2) | 86.2 (1.8) | 95.2 (4.2) | 87.1 (5.6) | 101.5 (2.7) | 101.4 (6.9) | 117.8 (4.4) | 99.1 (3.5)** |
| FL (N) | 67.1 (3.4) | 76.8 (3.2)* | 86.6 (1.9) | 86.8 (4.4) | 115.4 (3.0) | 119.3 (3.5) | 126.7 (4.1) | 111.9 (3.2)** |
| YE (mJ) | 39.8 (1.6) | 41.0 (4.6) | 40.7 (2.8) | 35.9 (2.8) | 25.5 (2.5) | 28.4 (3.2) | 36.4 (2.4) | 27.7 (2.7)* |
| FE (mJ) | 79.6 (4.4) | 75.3 (4.1) | 75.2 (7.7) | 66.7 (6.7) | 50.4 (3.3) | 54.8 (3.1) | 48.5 (3.0) | 42.1 (2.6) |
| PYE (mJ) | 39.8 (4.6) | 34.3 (4.2) | 34.5 (6.2) | 30.8 (6.3) | 24.8 (3.7) | 25.8 (3.3) | 12.1 (2.0) | 14.4 (2.9) |
| Stiffness (N/mm) | 107.1 (4.2) | 104.2 (5.2) | 154.9 (12.1) | 141.3 (15.7) | 315.2 (18.7) | 265.0 (22.6) | 267.0 (18.7) | 271.5 (21.5) |
| YS (MPa) | 118.9 (4.5) | 117.3 (5.4) | 138.2 (7.7) | 126.0 (9.3) | 120.3 (5.3) | 130.1 (9.0) | 131.2 (5.7) | 116.0 (5.5) |
| YT (mJ/mm3) | 3.27 (.22) | 3.38 (.32) | 3.26 (.25) | 2.90 (.24) | 1.74 (.15) | 2.03 (.22) | 2.32 (.15) | 1.87 (.21) |
| EM (Gpa) | 2.73 (.16) | 2.51 (.10) | 4.10 (.37) | 3.74 (.47) | 6.41 (.50) | 6.34 (.49) | 5.31 (.58) | 5.58 (.46) |
| Tibia | n=12 | n=12 | n=12 | n=12 | n=12 | n=12 | n=12 | n=12 |
| YL (N) | 56.7 (2.2) | 60.5 (3.0) | 68.6 (3.4) | 70.3 (2.4) | 81.2 (2.5) | 79.4 (2.5) | 90.0 (2.53) | 85.1 (3.7) |
| FL (N) | 67.6 (3.4) | 66.6 (2.6) | 70.4 (4.8) | 71.8 (3.4) | 86.4 (3.3) | 82.2 (3.6) | 98.6 (2.49) | 88.9 (2.4)** |
| YE (mJ) | 18.3 (1.1) | 21.4 (1.8) | 27.0 (2.3) | 27.2 (1.8) | 26.1 (2.2) | 25.6 (1.5) | 28.4 (1.98) | 30.2 (3.4) |
| FE (mJ) | 53.9 (5.7) | 58.2 (4.1) | 60.6 (5.9) | 76.3 (9.9) | 75.2 (12.1) | 68.3 (5.5) | 65.5 (4.39) | 61.1 (7.1) |
| PYE (mJ) | 36.1 (6.8) | 36.8 (3.2) | 35.8 (6.9) | 49.9 (11.5) | 49.1 (11.1) | 42.8 (4.6) | 37.1 (3.83) | 31.0 (4.8) |
| Stiffness (N/mm) | 109.0 (5.0) | 107.7 (5.7) | 115.6 (19.2) | 106.1 (9.3) | 171.2 (11.7) | 156.5 (9.3) | 183.2 (9.3) | 162.9 (12.1) |
| YS (MPa) | 139.1 (5.5) | 155.0 (11.1) | 179.6 (7.9) | 173.1 (9.5) | 175.5 (7.2) | 173.4 (4.1) | 183.1 (5.1) | 187.4 (3.7) |
| YT (mJ/mm3) | 2.28 (.15) | 2.74 (.21) | 3.18 (.29) | 3.06 (.25) | 2.53 (.22) | 2.46 (.15) | 2.72 (.20) | 2.94 (.28) |
| EM (Gpa) | 5.35 (.31) | 5.50 (.52) | 6.55 (.68) | 6.07 (.50) | 8.46 (.90) | 7.77 (.47) | 8.00 (.52) | 8.17 (.63) |
* and ** denote p ≤ 0.05 and 0.01, respectively, between landing group to the time-matched sedentary control group. EM, elastic modulus; FE, fracture load energy; FL, fracture load; PYE, post-yield energy; YE, yield energy; YL, yield load; YS, yield stress; YT, yield stress.