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.