This clip was created to show front side usage..Okay, I do not agree but I understand what you are saying. Now let's return to this clip. Does Federer qualify as "maximum leverage with both legs grounded" in this clip?
So you disagree that these 3 clips aren't maximum leveraged against stretching obliques (core) ?
Is it possible there are multiple movement patterns ? Or do you think they are all doing the same thing but different styles ?