I was going though some article on spine and what kind of posture affects what and I found something interesting.

If you are sitting continuously for longer hours it is harder on backs then standing because when you stand the spine is in a state called lordosis - with pressure evenly distributed along the 24 vertebrae of your backbone. Blood flow along the spine is fee and unobstructed. When you bend the body at a right angle in sitting, you flatten the lumbar (lower section) of your back.

In fact, sitting is harder on your back than standing.

Most people think your backbone supports your body. It doesn’t. Your body actually supports your backbone!!.

Your back’s 24 vertebrae and its jelly-like disks offer you flexibility, but not much strength.

The less we move while sitting, the less our bodies are able to supply parts of our bodies with vital nutrients. When your lumbar area is nutrient-deprived, those fluid-filled disks harden.
As they become less flexible, your body is more vulnerable to injuries caused by motion.

And sitting incorrectly, essentially crunching your lumbar area, will gradually erode the disks in your back over time.

Sitting for just 20 minutes can so reduce the flow of nutrients to your disks that they begin to harden. So if your chair is too soft and fluffy, your body doesn’t really move much.

It’s almost like being encased in a foam-rubber body cast. No movement. No nutrients. And your disks pay the price.