i recently upped my cardio drastically and my knees are suffering. the shoes i'm using are complete dogshit and i'm going out to buy new ones today. i searched and noticed that a lot of people recommended going to a running store and to get my stride analyzed, etc. my question is more directed at what kind of shoe i'll need for uphill treadmill walking. is a different kind of shoe needed for this rather than one for running specifically? should i get a cross trainer instead?