We used to think that there was such a thing as “good and bad posture”
Can certain postures lead to problems, yes. But this has more to do with lack of mobility and strength to tolerate that particular posture, and the specific person than with the “bad” posture.
Lack of changing positions leads to more problems than the position itself. What is a bad posture for some is a position of relief for someone else.
If a posture is inefficient it can lead to issues, especially if you load it with exercises or prolong positioning and if you have certain positions that are painful, you should avoid it until you have build up enough mobility and stability to make that posture more efficient.
Myth: Bad Posture Causes Pain
No evidence to support it. It’s very person-specific
Myth: Perfect Posture Prevents Injuries
Again, there is no evidence for it. People with good posture can still have injuries and overuse problems if they don’t change their position regularly
What Can I Do?
The most important thing you can do is to change positions regularly. If you have been slouching, try to sit up straight for a while. If you have been standing for a while, sit down. Interrupt sustained positions!