I have a quick question for you if you do.
Quote from TraDaToR:
The second one of course. I have one at home. It is not that easy and a good exercice for balance.
I bought it 8 years ago when I was reeducating from a knee ACL surgery( snowboard injury ).
It is even better for your ankles, probably one of the best exercice for ankles. I do it every time I roll an ankle skateboarding( 2-3 times a year ).
