Re: opening the joints
Well, remember that for clarity's sake on these lists I tend to artificially separate "ki" and the "kokyu/jin" forces. Both of these can be thought of as the Yin and Yang aspects of Ki. Both of them have to get to the extremities. If some part of your body is "closed", the ki won't go there. Does that give you an insight into a different use of the term "open"?