rojcewiczj wrote:What though is the use of the pelvis? It is only to keep every movement within the energetic frame of the pelvic structure.
Sorry, I have no idea what is the meaning of "keep every movement with the energetic frame of the pelvic structure".
Regardless, your response doesn't seem to address the point I made, that the use of the pelvis shown in the Wing Chun video you posted is different than how the pelvis is used in at least some of the "internal" martial arts.
The body is comprised of a number of (semi) rigid linkages that are connected at joints, the whole of which can be arranged to form a chain. The chain of linkages are connected via connective tissues. These tissues can allow one linkage to move relative to another, or hold the linkages in place, one relative to the next. The "pelvis" is part of that connected chain of linkages. Without the involvement of other parts of the chain, "the pelvis" is unsupported. It is one part of a number of parts that form a structure. One might argue that "the pelvis" is more important than other parts of the chain, or the structure it forms, but one can't ignore the rest of the chain. "Internal" martial arts usually stress the importance of getting those individual linkages all working together, often from the point of application to the ground.
As an aside, when you refer to "the pelvis" are you discussing the hip joints, the musculature of the abdomen, the lower spine or something else?