Man, I really hope Sunny will have her knee fixed in the near future.. To my selfish mind, she shouldn't be performing dance routines at all while she has the inflammation, but I guess the culture of Kpop is a lot harder then anything I'm used to :/ Notice when she gets off the chair at 2:12, her right foot treads normally, while she walks on the balls of her toes with her left.. Being active with a damaged knee is not healthy in the long run... Best of luck Sunny