Physiotutors
INTERVERTEBRAL DISCS NEED LOADING TO BE HEALTHY!

A recent publication from the NASA showed an increased incidence of intervertebral disc (IVD) herniations in US astronauts of 10% (32/321) with the highest incidence (19%) within 1 week directly after spaceflight.
Control group incidence on normal population on earth: 3,5%.
Incidence in the cervical spine was 21.4 times higher than in the lumbar spine.

Belavy et al. (2016) reason in their narrative literature review that the most likely cause of IVD herniations is swelling of in the unloaded condition during spaceflight due to hyperhydration.
According to them, the IVD is especially vulnerable to increased pressure from flexion in this state.
However, they could not find an explanation why IVD herniations in the cervical spine occured way more than in the lumbar area.
Research covers the lumbar spine more extensively than the cervical spine, especially when it comes to spaceflight.

On top of the changes in the disc, the authors argue that muscle function due to atrophic changes usually takes months to recover. This can lead to impaired sensorimotor control, which can decrease the protection of the IVD by the muscular system.

Vertebral body bone loss in spaceflights may influence the IVD as well, because loss of bone mineral density has been demonstrated in astronauts after spaceflight as well.

Of course a narrative literature review will not enable us to draw any conclusions. However, one message that we derive from this is:

A HEALTHY SPINE NEEDS LOADING!
This is a great study to tell our patients who are afraid of lifting!
More info @ http://ift.tt/2ntRCbS
Automated post from Douglas Physiotherapy & Sport Injury Clinic – http://ift.tt/1BNPfjC
April 02, 2017 at 04:03PM