You’re either going to lean hard against your left palm as it rests on the control panel which isn’t comfortable for very long or, like most people, you’re going to grab the side of the game and hold on tight. You have to or you’ll lose your balance. You can’t take the sharp corners smoothly and quickly without doing this, ether. You need the extra stabilization to move Pac-Man around the corners accurately.
All of these different "stances" speak to the legacy of the game