Counter: sitting position and different seats

According to the Swiss Health Observatory, we sit for an average of almost 6 hours a day. A quarter of the Swiss population spends as much as 8.5 hours sitting. Hence the importance of adopting the right posture, as poor posture can have consequences for our health. But how can we be sure we're sitting in the right position? What can you demand of your employer in terms of workstation layout? And how can we force ourselves to stand up?