Stop sitting up straight!
There! I said it. I know it goes against everything you've ever been told and that everyone always says about workplace setups. But I think it’s unrealistic to expect busy people to focus on a Yogi like, iron straight spine all day at work.
What is best for our body is to move. Standing all day, sitting all day, lying down all day, hopping on one leg all day, nothing is good if you do it too much. Moderation remember. But when it comes to your job it’s also unrealistic that you move around every 30 minutes unless you’re a chair based fitness instructor. What I am suggesting is that you actually try to relax at your desk. You need a chair that slopes backwards and has a lumbar support. This way you can lean back into the chair and it will keep your spine in a “straight” neutral position but also relaxed so that you don't get fatigued and end up in pain.
The issue with sitting up straight is that most people don't have the muscular endurance to hold them up all day so what happens? Gravity happens. And you end up collapsing forward. You know the position I’m talking about. In fact, you’re probably doing it right now. The screen slump position. This position also puts an increased pressure on your lumbar intervertebral discs which can lead to increased wear and tear on the discs and even potential disc herniations and protrusions.
Below is a graph that shows the amount of muscle activation (left column) required depending on the angle of the backrest of your chair (bottom row) which suggests as I said earlier, that sitting upright requires more muscular endurance and will lead to muscle fatigue and eventually pain.
How posture affects disc pressure in your spine
The image above shows that sitting upright at 90° actually puts a lot more stress on the disc. You can also see the most pressure on the lumbar discs is when you are slumped forward in your chair. Standing up and reclining to around 110° put very little extra stress on the lumbar vertebrae.
So if you are getting pain in your back when you are sitting at your desk and you have tried sitting upright it may be time to try reclining your chair and relaxing at the desk or even having a sit-stand desk where you can also stand up for a portion of the day.