A recent journal article discussed the effects of spaceflight or lack of gravity; on the spine. The journal article “From the International Space Station to the Clinic: how prolonged unloading may disrupt Lumbar Spine stability” published by Jeanne Bailey and others in January 2018 highlights the benefits of weight bearing.


Exposure to space causes muscles to get smaller (atrophy) and bones to lose calcium. Astronauts who return from space are at increased risk of developing low back pain (LBP). NASA studies have found a 43% incidence of LBP in astronauts during spaceflight and nearly 3X increase in herniated discs after returning to the earth!!!

Low Back Pain

Interestingly, astronauts experience “spinal lengthening” or swelling of the intervertebral discs, causing people to become taller while in space. This finding is because space has no gravity. Remember, the biggest reason the elderly get shorter is because our discs begin to flatten and degenerate which is related to gravity’s effect on humans.    http://drpaulsaiz.com/lumbar-disc/

Dr. Paul Saiz

The study followed prospectively 6 NASA astronauts before and after going to space. The researchers found that the muscle shrinking (atrophy) around the spine was strongly associated with post-flight loss of the normal low back posture and loss of range of motion. They concluded that the muscle shrinking specifically involving the multifidus; was the main reason astronauts were at risk for LBP. “Multifidus atrophy appears associated with spinal flattening and increased stiffness.”

These findings are important for targeting low back muscles here on earth, for people who have LBP. Ultimately, weight-bearing exercise and CORE muscle training is one of the best ways to decrease your risk of LBP.  Click here to learn more. 


Paul Saiz, MD


Bailey J. et al: “From the International Space Station to the clinic: how prolonged unloading may disrupt lumbar spine stability.” The Spine Journal: January 2018