Growing spines in space: The mystery of astronaut height

Growing spines in space: The mystery of astronaut height

The Space Stretch: Why Astronauts Get Taller in Orbit!

Have you ever wished you could be a little taller? Well, for astronauts in space, it actually happens! When they're floating around on the International Space Station, many astronauts report that they become slightly taller. This isn't magic, but a fascinating change that happens to their spine because of the absence of gravity. It's one of the coolest mysteries of human adaptation to space!

Gravity's Squeeze: How Your Spine Works on Earth

On Earth, your spine, or backbone, is made up of many small bones called vertebrae stacked on top of each other. Between each vertebra are soft, jelly-like cushions called intervertebral discs. These discs act like shock absorbers, protecting your spine and allowing it to bend and twist. All day long, gravity gently presses down on these discs, slightly compressing them. This compression is normal and part of what gives you your everyday height.

The Space Un-Squeeze: Spinal Elongation!

In space, there's no gravity to push down on the spine. So, those intervertebral discs, no longer compressed, can actually relax and expand slightly. It's like taking the weight off a spring – it stretches out! This "un-squeezing" allows the spine to lengthen a bit, making astronauts temporarily taller. This phenomenon is called "spinal elongation." Astronauts can gain an inch or two in height while in orbit!

Back to Earth: The Shrinking Return

While getting taller might sound fun, it's not always comfortable. The stretching of the spine can sometimes cause back pain for astronauts. And, just like all the other body changes in space, this one isn't permanent. As soon as astronauts return to Earth, gravity immediately starts to compress their discs again. Within a few days or weeks, their spines return to their normal length, and they go back to their pre-flight height. It's a great example of how our bodies constantly adapt to the forces around us!

Key References:

• Belavy, D. L., & Adams, M. A. (2009). Disc degeneration in microgravity: Does it occur and how does it relate to back pain? Spine, 34(15), 1604-1608. (Discusses spinal elongation and its potential relationship to back pain).

• Bailey, J. V., & Fortney, S. M. (2018). Musculoskeletal System. In Human Physiology in Space (pp. 57-79). Springer, New York, NY. (Includes discussion of spinal elongation as a musculoskeletal adaptation).

• International Space Station (ISS) Official Website: Often includes fun facts and explanations about changes to the human body in space, including height changes.

• NASA Human Research Program: Provides information on spinal health and musculoskeletal changes in microgravity.