The Pique Turn

In ballet, we did pique turns across the floor. At the time, I was not thinking torque, but there was certainly a lot of physics at work. So...What keeps a dancer from falling?????

To successfully complete a pique turn, there are certain things that a dancer has to be aware of, such as body placement. We say to bend the knee to push off the ground, pull up, have straight legs, hold the arms up, spot so we know where we're going and to not get dizzy, turn the knee out, hold the head up...
and in physics this would mean...!
In the first step, in order to even get up en pointe and balance, the dancer in the picture has to bend her knee. This provides a force for the dancer to push off the ground. This force is also what helps get the dancer to turn...torque!

By step two, the dancer need to have a center of balance, a center of mass. Everything need to be in line over the box of the shoe (which is the part that the dancer stands on). If the dancer leans to much back, side, or front, then she'll fall because her weight would not be on her center of mass.

During the turn, the dancer can't change any of her body position because that would throw her turn off. If she can hold her placement, she can do multiple turns before landing!

When she lands, she needs to continue to keep everything in line over her center of mass in order to land neatly in a fifth position. By bending her knees, the shock of landing is more easily absorded.