When I was doing PT for my knee this summer, they had me doing squats as described above in #'s 1 and 3. When I first started out, they wanted me to hold on to something counter-height to make sure I didn't go down too far. I found that awkward, but I have a treadmill at home, and when the base is folded up, the arms were at the perfect position to grab. And since it would wobble a little, it kept me from attempting to do anything drastic. :->