I do this myself, but I really experience it as bracing myself using my feet, to avoid having my torso and head move forward when the car brakes. The handle is handy (!) for the same purpose.

People always seem to think that I'm "ghost-braking", but I'm pretty certain I'm just trying to stabilize my body because it's uncomfortable to be jostled around. I don't "ghost-blinker" at corners ...