There are actually different stances other than prone, crouch, and standing. If you press Ctrl+w/s you can go through several stances of varying heights and poses and Ctrl+A/S to do extended leans and lay on your sides.

@arziben I by no means am comparing this to Call of Duty, just referencing where this technology has been implemented. I do not prefer to hate on any company or organization and therefore use the brand name freely. But back to the point:

I just wish to have this for convenience sake,to help out people like me who wish to make a movie or playback key moments in a battle without to tediousness of recording every minute of game play. However it is only an extra bonus to the already great game coming out; like I said, it's only a suggestion.

They stated in demonstrations that vehicle weight and physics will have an important role in the environment, so they probably haven't fully implemented it in the Alpha, wait for the beta and they may end up fixing it.