"Frame" comes up a lot with Aunkai folks. It's sort of a shorthand for all the connection/internal/structure work that the exercises help to develop. Mabu/the cross/shintaijuku/spear thrusting all serve to develop the frame. I find that "frame" also comes with a lot less baggage than "internal skills", or "IT".
I actually like using kettle bells for some connection/frame training since almost all of the basic KB exercises pass movement through the core of the body out to the limbs and also reinforce dynamic balance.