In this video Jeff discusses the exercise "Twist and Coil the Qi."
This exercise is excellent to help develop Peng - or outward expanding pressure, and Jing - elastic energy.
If you are just beginning this exercise, you can practice while standing more upright to keep your knees, hips, and back safe.
As you get stronger you can 'sink into' the posture. Just listen to your body and take your time!