Blog Post #3: Bone Loss in Space

Trabeculae in the spongy bone of the femur.
Source: http://www.gla.ac.uk/t4/~fbls/files/fab/tutorial/generic/bonet.html

On Earth, bones like the long bones in our femurs and the vertebrae in our spines change shape based on the amount of gravity applied to them. Inside those bones is specific bone called trabeculae. Trabeculae is
lightweight and thin, but very strong and supportive. Trabeculae are what make up the spongy bone in bones.

An astronaut lifting weights in space.
Source: http://www.tested.com/science/space/456642-
iss-experiments-cause-bone-loss-space/.

In space, the human body recognizes there is no gravity and bones begin to change. Since the same applied forces are not continuously applied to our bones, the trabeculae start to thin. In a 50 year-old woman on Earth that has not been diagnosed with any bone diseases, can lose up to 2% of the trabeculae in her hip bones. An astronaut can lose that same amount in one month. NASA has designed special exercise equipment and an exercise program for their astronauts while they are up in space so their bones can stay strong and healthy. The astronauts lift weights and work out for 2.5 hours a day for six days out of the week. It takes a person three times as long to regain the lost support in their bones as it does to lose the bone, so it is important that astronauts apply pressure to their bones while flying in space.



Source for this article: http://www.nasa.gov/exploration/humanresearch/index.html#.UugXV2Qo7-k