I think the whole gesture is moving the way it's moving already, changing the palm a bit is not really going to make any difference, just make the animation less focused. the hand that's producing the pillar is clearly the one punching the ground, involving the other one would be inconsistent.
We've seen games have people punching the ground and pillars coming out anywhere the characters want by now, besides the fact the previous hit is the same color as this one.
if you feel like you really have to do something to imply it maybe just give him eyes and point them towards the pillar as he punches the ground, or hell, slightly make his whole torso turn towards the pillar as it comes out, sort of reacting to it...you know like the way you sort of straighten up in your seat when you make a char jump in a videogame.
also, since you added movement to that arm I noticed that you kinda just shortened it, it's not really bent or in perspective or anything it's just short...do fix that