We do focus on balance, and there is one move where we balance on one foot. I tried it last week and it was a toughie! My poor knees were screaming. So before class today, I asked her what I could do instead, and she said she would show an alternate balance pose that used two feet. When we came to the balance portion of class, she gave us a choice between one foot, or two? Guess what? Everyone chose two, not so much because it was hard, but because of the same reason, we are in pain and we know its not gonna get better.
So the lesson in all of this? Speak up, chances are likely that you are not the only one having trouble!
I found a great chair yoga version of the Sun Salutation, love this, what a great total body stretch for after my morning tai-chi.