On rumsoakedfist there is a link to “Essence of Combat Science” by Wang Xiangzhai as translated from Chinese by Andrzej Kalisz. Click here to go to the file.
Wang Xiangzhai wrote :-
In shi li there shouldn’t be partial, superficial force, especially there shouldn’t be unbalanced one directional force. You should observe if the whole body force is round, full or not, if it is possible issuing force at any moment, if there is feeling of mutual reaction between body and surrounding air. Intention shouldn’t be broken, spirit shouldn’t be dispersed. Light and heavy are ready to be used. If one moves, whole body follows it. Force should be unified, swift and solid at the same time, round and full. There shouldn’t be anything forgotten or lost on any side.
The above is good advice to keep in mind when practicing how to issue power.
In our Tai Chi tradition we have additional requirements such as :-
a) Have defined intent to control body movements
b) Align and tune the body internally to allow power to flow like a spring gushing out of the ground
c) Prime the 5 bows strongly to enable quick conversion of energy from potential to kinetic
An example of using these three requirements is shown below :-