Table 2

Correlation between the impact exercise at 0-3, 0-6 and 0-12 months and bone geometry changes

Average daily numbers of impacts at different acceleration levels

0-3 months

0-6 months

0-12 months

0.3-

1.0 g

1.1-

2.4 g

2.5-

3.8 g

3.9-

5.3 g

5.4-

9.2 g

0.3-

1.0 g

1.1-

2.4 g

2.5-

3.8 g

3.9-

5.3 g

5.4-

9.2 g

0.3-

1.0 g

1.1-

2.4 g

2.5-

3.8 g

3.9-

5.3 g

5.4-

9.2 g

Mid-femur

Bone

circumference

-0.02

0.17

0.07

0.22

0.45⁽*⁾

0.01

0.21

0.35

0.37

0.45*

0.04

0.23

0.39*

0.41*

0.45*

Cortical

CSA

0.08

0.37

0.35

0.28

0.06

0.33

0.26

0.41⁽*⁾

0.39⁽*⁾

0.12

0.36

0.26

0.41⁽*⁾

0.43*

Cortical

attenuation

0.08

0.43⁽*⁾

0.41⁽*⁾

0.52⁽*⁾

0.49⁽*⁾

0.10

0.47⁽*⁾

0.51*

0.54*

0.51*

0.18

0.52*

0.54*

Max

cortical

CSMI

0.27

0.38⁽*⁾

0.29

0.34

0.39⁽*⁾

0.29

0.41⁽*⁾

0.39⁽*⁾

0.38⁽*⁾

0.42⁽*⁾

0.38⁽*⁾

0.46*

0.42*

0.43*

0.45*

Cortical

thickness

0.04

0.40⁽*⁾

0.33

0.31

0.26

0.00

0.38⁽*⁾

0.30

0.44⁽*⁾

0.39⁽*⁾

0.05

0.41*

0.30

0.44*

0.41*

g acceleration of gravity (9.81 m·s^-2), CSA cross-sectional area, CSMI cross-sectional moment of inertia.

* p < 0.05, after Benjamini-Hochberg correction for multiple comparisons

⁽*⁾the association did not remain significant in multivariate analysis after adjustment for impacts at later months and other confounding factors.

Pearson's correlation coefficients (r) between the impact exercise at different acceleration levels in 0-3, 0-6 and 0-12 months, and changes in cortical bone geometry measured with quantitative computed tomography. N = 35

Ahola et al. BMC Musculoskeletal Disorders 2009 10:138 doi:10.1186/1471-2474-10-138