I like how the author developed it. The first couple of strong kicks knocked him down each time, but he gradually become able to remain standing while wobbling and losing his balance a bit, and then finally was able to withstand the strong kicks to the point that he could stay standing while also remaining close to his original position with minimal wobble.
Of course, that last power kick also knocked him down, and his thighs and ass will be so bruised that he won't be able to sit for a week, but eh.