Good Question

Kevin Moody asked a good question in response to my "Taking advantage of the topography" post I thought deserved a separate post:

"Just tried some retro & side walking on the treadmill with an incline pitch. Had to slow the speed down for the side walking. Could definitely feel the quads working on the retro walking but wasn't getting much on the side walking. However, I was only experimenting and did not have a lot of time play with it.

Any thoughts?"

That would make sense Kevin.  If you were walking down the hill, the lead (lower) leg would be resisting momentum and abduction.  On the treadmill, there is neither.  In order to get the same effect on  treadmill, I'm thinking you would need to do a tapioca with the affected leg to the rear.  Safety would become an issue; be sure you have a bar to hold onto.  Try it and give me your thoughts.