Decreased Bone Density Pls..answer, Its About Bone Density..im Running Frm Tomorrow!!?

Pls..answer, its about bone density..im running frm tomorrow!!? - decreased bone density

Hi guys ..
I have my wood, so I thought, I begin each day to lose weight.
I know what the bone density, and I know that the child .. Bones are weaker UR.
As always ready to play sports that have a high degree of danger to physical health ... I started tennis wen .. I have a tennis elbow and I began skateboardin Wen .. i broken leg and arm --

and now it works .. Neways back to the point ..
I Wish U to answer the following questions

1. The increased use or reduced bone density?
2.Is desity bones have something wrong?
3.How do u avoid that low bone density

now .. in freaking out .. starting to run scared Cuz I wannna in case problems arise with bone ..

thnx a lot ur time to answer my questions ...

Cheers
xoxoxo
mwa