I actually skip the entire pose – it seems that just tree aggravates my knee. I am pretty inflexible and never made it to toe stand anyway. But skipping this pose and skipping fixed-firm pose has resolved my knee problems. Sometimes when my instructor takes notice of my skipping these poses he says “well maybe bikram is not for you”, and I just ignore him. Maybe I will become more flexible and in the future be able to do them, but for now the remaining 24 postures do me wonders.