Amare has physical limitations that limits his post game. He lacks good center of gravity. The guy is very top heavy so it is hard for him to back some of the bigger guys down. This also has contributed to his knee injuries since his lower body has trouble handling the abuse his upper body puts on it. This isn't something that can be physically corrected, it is just they way he is built.
Even Clyde has pointed this out numerous times during the pre-season.