To be loose means to be relax but with peng energy which just react when your opponent pushes you and you deliver the same amount of energy so he can not get in. If you really want to issue energy, that energy should come from your feet to your kua and then to the contact point of your opponent. Our upper part should be like a rope and our legs and kua are like a trunk with which we hit. We should attain the level to be able to use always a leverage. Only use a minimum of energy to create a powerful action and that comes front rotation of our kua.