a. (preliminary movement) Standing, heels together, arms limp at sides. Bend to the side, dropping one arm down, and lifting the other up to the hip. Then bend to the other side, with no pause, in a smooth motion. Do this for four full breaths.
b. (the rubbing) Start with hands flat against the hips, fingers pointing down.  When bending to the left, the left palm strokes down the outer side of the thigh as far as the knee.  Simultaneously, the right palm will slide up the side as far as possible towards the armpit.  Reverse this movement when bending to the right.  Do not hold your breath!  As you progress in this movement and it becomes faster, do not neglect the force with which you do the rubbings or the length of the movement.

(excerpt from fan summary)