I just got my cast taken off for a sprained ankle and now i'm trying to do...

[lolcats]

...pointe ballet? my doctor told me to wait a week before exercising and it's been a week. the back of my knee hurts (like the bottom part where it starts to be my calf) and when i'm on pointe my leg is very weak. it's annoying because after being in my cast for 6 weeks my left leg is stronger than ever yet my right foot is weak! what can i do to strengthen it to get back to regular on pointe? are there exercises i can do to speed up the process? thanks