PLIE' : The bending of the knee or knees. It is applied to help develop a sense of balance and help the muscles, joints and tendons soften and become more flexible. There are two types of plie's : Grand plie' and demi plie'. The grand plie' is the full bending of the knees - knees should be bent till thighs are horizontal. In this plie' heels do come off the ground. The demi plie' on the other hand is the half bending of the knees, where feet are planted into the floor and heels do not rise. Plie's are done at the bar and in all five foot positions. To have a correct plie', all plie's must have the legs well turned out and the body weight well distributed throughout the body, having both feet planted firmly into the floor. http://www.youtube.com/watch?v=1To1WWo1Oo0