What happens to your intervertebral discs when you sit?
What happens to your intervertebral discs when you sit? 16 Sep 2019
Sitting in office chairs for long periods of time not only affects your muscles but impacts the disks in your spine.
In humans over 5 years of age, there is no direct blood supply to the jelly like nucleus of the intervertebral discs.
The intervertebral discs therefore rely upon fluid inflow and outflow for their nutrition: when you lie down, the pressure comes off the discs and they expand, absorbing water and nutrients as they do so (rather like a sponge expanding and sopping up a spill on the floor).
Unloaded Disc Filling with nutrient rich liquid
When you stand up, the discs are compressed and their watery component is squeezed out, thus removing waste products at the same time.
Loaded Discs Being Compressed
Similar squeeze/expand cycles are occurring every time that we move, both day and night. This means you must move in order to “feed” your discs and keep them healthy. The disc squeeze/expand cycle is crucial to spinal health. It is well proven that your degenerative disc "disease" progresses faster over time if your discs can't alternate compression with expansion. As sitting more than half the time at work is associated with herniated discs (or slipped discs) and sciatic nerve pain in those older than 35, so try to get up and move as much as possible.