Old Space: Protecting Young Bones from Weightlessness. A Conversation with Thomas Lang
Thomas Lang
Weightlessness has always seemed liberating, a real and metaphorical escape from our daily burdens, almost as I imagine flying would be.
And astronauts certainly look happy – almost giddy, in fact – when you see them floating freely inside a space vehicle. And why wouldn’t they be happy? Floating in space must be an astonishing, other-worldly sensation for a species like humans, held so firmly in place by gravity.
But we are terrestrial beings. Evolution has shaped us. Our bones and muscles draw strength from the very force pulling against them. We pay a price for leaving Mother Earth. And that price can be measured in dramatic fashion on some of Thomas Lang’s CT scans.
To be precise, says Lang, PhD, crews of a long-duration space mission typically lose as much as 1.5 percent of bone mass from their hips per month of spaceflight. Compare that with age-related osteoporosis, particularly in elderly Caucasian women, where a bone mass loss of less than 1 percent per year is considered serious.
Computed tomography images through the hip of an astronaut showing bone loss and recovery after a 6 month mission aboard the International Space Station. PRE: image taken before flight. POST: Image taken at mission completion. 12: Image taken 12 months after end of mission. The red arrows show regions of high bone loss.
Worse, adds Lang, his 2004 study of space crews revealed that after one year back on Earth, their bone mass had still not recovered fully. True, his imaging technique of choice – known as volumetric quantitative computed tomography – did show that total bone mass had bounced back. But while the hipbones were larger, they were not as dense. In essence, the hipbones had reformed – or remodeled – themselves based on the degree of strain experienced by bone-making cells.
Armed with that data, Lang and his colleagues set out to create a new kind of all-in-one exercise device that future space crews, as well as those living on a proposed lunar base, could use to preserve both bone and their sense of balance. The goal now is to test it on volunteers confined to bed. What they learn could change not only the future of space travel, but also the nature of care for the frail elderly.
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Related Links
- UCSF Center for Molecular and Functional Imaging
- Project Technical Summary: An Integrated Musculoskeletal Countermeasure Battery for Long-Duration Lunar Missions
- National Space Biomedical Research Institute (NSBRI)
- Volumetric Quantitative Computed Tomography: Characterizing the Effect of Long-Duration Spaceflight on the Structure of the Hip (pdf)
- (pp. 14-16) Images, 2006, UCSF Department of Radiology
- No Place Like Home – In Space
- USA Today, April 4, 2007
- Lost in Space: Bone Mass
- Radiology Today, August 2, 2004
- UCSF/Baylor Team Uses New Method to Measure Bone Loss in Astronauts Flying Long Missions
- UCSF News Release, March 8, 2004
- Weightlessness – Health Effects
- Wikipedia