Ideally you aren’t slamming all of your weight on your ankles with every step though. If you do that at human scale with normal human weight, there won’t be much of your ankles left either. Your muscles work as a spring to catch most of the force and they also grow cubicly. So i think the law cannot be applied this directly to biological systems. Of course you are right, that King Kong would probably not just be a scaled up Gorilla, but also altered in his shape.