All power comes from the ground. While many techniques are taught as if the power comes from the hips, the hips are able to generate power because support from the legs into the ground. What JW is saying is correct, but take that further.... the energy begins at the point of grounding to the ground, it then travels through the legs, to the hips, then to the upper body, finally to the point where the technique ends. If you think about each technique as beginning at the ground, you may discover new ways of thinking about how power is generated.