It is true but one does not need a special chair as much as learning how to sit on any chair. If the chair is really comfortable it invites the sitter in really bad unnatural positions and in no time that creates a bad habit. During my 20s, when I basically entered the workforce, I started having serious issues with sitting. I tried a lot of different chairs and while they ameliorated the pain and numbness something was still wrong. Now, almost at twice that age I have very few chair/back related problems. When something hurts I closely pay attention to how I sit. Of course, exercising with proper posture has helped me overcome some of my issues as well. While most chairs are really bad for most of us, I think chasing a perfect chair is not the solution but learning how to sit and have a proper posture is the essential part.