Personally, I can't get into the 'proper' position when sitting at all, my arms are too long. I'm 6'2" ~190lb and when sitting in an ergonomic chair with proper posture, my elbows are within an inch of the top of my quads. Attempting to sit properly at a desk requires my quads to be jammed into the underside of the desk which is horribly uncomfortable. The only thing that is comfortable when sitting is raising the desk up a lot and extending my arms way into the desk to the point where my arms are nearly at shoulder height.