Your posture is determined by your arm swing. If you swing up and down on a two plane swing then you should stand more upright. If you swing your arms around on a one plane swing then stand more bent over on the balls of your feet.
The same arm motion that is important in the one plane swing should be used when putting to create a consistent repetitive putting stroke
Mike started his daughter out playing softball before she moved on to golf. The baseball swing is identical to the one-plane golf swing; the only difference is that in golf the strike zone is on the ground where your ball is.