Many monitors that we buy these days are not positioned high enough to make us sit straight while looking at them. The thing that I found to be very useful to keep my back straight was to put something under a monitor like, for example, a few books. Today, I am very comfortable when sitting in front of my computer. I no longer have to lean on my desk to be able to view properly what is going on on my screen, and my back is not aching anymore. I think that it is very important in what position you sit in front of your computer, especially if you sit many hours per day. If you are still young, you might not feel any pain, but when you get older you might. It is better to take care of those things right now rather than later in life.