new study by Dr. Douglas
G. Chang of University of California, San Diego, and colleagues, published in Spine
that astronauts who embark
on long mission space flights suffer from atrophy of muscles that supports the
spine, taking a toll on their back.
‘Preventive measures such as incorporating core-strengthening exercises to astronaut training programs and practicing yoga could be effective for addressing backache and spinal disc diseases.’
condition does not return to normal even several weeks after their return to
"This could provide helpful physiological
information to support a manned mission to Mars," the researchers write.
The inter-vertebral discs create a cushion between vertebrae in a person's spine. Any change to its shape and size can
affect the spinal column and back.
have been reporting back pain since 1980's during prolonged mission, especially
lower back pain. Around 28% indicated that they experience moderate to severe
Aim of the
The long-term objective of this project
is to promote spine health and prevent spinal injury during space missions and
The goal was to understand factors that
affect lumbar spine strength and the
source of low back pain during long-duration spaceflight, as
well as the how the spine responds after
returning to Earth gravity.
The data for the study
were obtained as part of a NASA-funded research
study, led by Drs. Alan R. Hargens and Jeffrey C. Lotz.
Methods and Findings of the Study
Six NASA crew members were studied before and after spending four to seven months in
"microgravity" conditions on the International Space Station.
Each astronaut underwent magnetic
resonance imaging (MRI) scans of the spine before their mission, immediately
after their return to Earth, and again one to two months later.
It was noticed that astronauts are
at increased risk of spinal disc herniation in the months after returning from
spaceflight, about four times higher than
in matched controls
. In the first year after return
from space, astronauts have 4.3 times higher risk of herniated disc
Though these changes cause an
increase in height by two inches, it is accompanied by weakening of muscles
supporting the spine.
The change in height is due to spinal "unloading" in
which the spinal curve flattens and other changes related to
the lack of gravity.
Astronauts do not use their lower
back muscles much as they do not bend over. This is the reason for pain and
To estimate lean muscle separated
from non-lean muscle components, researchers used an image
Lean muscles play a critical role
in spinal support and movement. The MRI scans indicated
significant atrophy of the paraspinal lean muscle mass during the astronauts'
time in space.
The lean muscle, or
"functional," cross-sectional area of the lumbar paraspinal muscles
decreased by an average of 19% from pre-flight scans to immediate post-flight scans.
The ratio of lean muscle decreased
from 86% pre-flight to 72% immediately.
A month or two later, only about
two-thirds of the reduction had recovered at 81% but was
still less than the preflight value.
"Even after six weeks of training
and reconditioning here on Earth, they are only getting about 68% of their
losses restored," Chang explained.
In contrast, there was no
consistent change in the height of the spinal intervertebral discs. Dr. Chang
and coauthors write, "These measurements run counter to previous
hypotheses about the effects of microgravity on disc swelling."
exercises to the astronaut exercise training
program.Yoga might be another effective approach
for addressing spinal stiffness and reduced mobility.
The results give
insight into back pain and inter-vertebral disc risks,
suggesting possible countermeasures targeted to the lumbar paraspinal
muscles while in-flight and during the preflight and after
The data reveal
lumbar spine paraspinal muscle
after long-duration spaceflight.
Though some functional
cross-sectional area recovery was seen 46 days after
space flight in a terrestrial environment, it remained
incomplete compared to pre-light levels.
Further studies will be needed to
clarify the effects on disc height, and whether they contribute to the increase
in body height during space missions, and to the increased risk of herniated
According to the study authors,
"Whether new exercise countermeasures can prevent in-flight paraspinal
muscle atrophy, improve spinal pain and function, shorten recovery time, and
how such exercise might be performed in a microgravity environment with
available exercise equipment need further study."
study shows that space travel affects spine of astronauts - (https:www.eurekalert.org/pub_releases/2016-10/wkh-nss102516.php)