The ballroom dance frame is typically thought of as the traditional closed Waltz frame. This is true in International Standard dancing because the two partners remain in constant three point frame contact with each other throughout the whole dance. There are, however, a variety of partnership frame connections in American Smooth, American Rhythm and International Latin dancing. These dances can transition between a full three point frame connection, to a two point connection, to a one point connection, to no connection (solo movements), during a single dance. You are a two-headed four legged animal as long as there is a physical connection between the two dancers. When you have no connection, you revert back to a two legged animal. It isn't easy (or normal) to bounce back and forth between two and four legs.
Dancers, in general, have problems maintaining a usable frame when they are not in a closed three point connection. The tendency is for dancers to use the arms and hands separately from the body. As we all know, the hands and arms are part of the body and the body moves the frame. An example is the crossover break (one point connection) in Rumba. Dancers typically try to lead the crossover by reaching with their arms instead of turning their body which results in the arms rotating into the crossover. The arms are not frozen, however, there is some action in the arms but it is very limited. The bulk of the movement is initiated from the body.
One of the major difficulties in maintaining the frame connection is transitioning between a three point connection to any of the others and then returning to the three point connection. The problem is usually that the dancers are reaching toward each other with their hands and arms to make the connection instead of letting their body movements bring their arms and hands back to the frame position. It must be remembered that no matter what positions the arms are in, it is still a frame and the frame is moved by the body.
The concept of the lady having continuous motion until the leader ends the movement accommodates the action of the body to connect the frame. An example would be a rumba crossover break to a butterfly. The rotation of the partner's bodies toward each other after the crossover break brings the open side of the frame toward each other so the patty-cake hand connection can be established to power the butterfly (fifth position) action. The body's rotation creates the pressure of the connection not a reaching of the arm and hand. The arm and hand is what stops the body rotation to create the frame pressure. If the patty-cake connection is initiated by the hand and arm, it is difficult to use your partner's power to execute the butterfly action.
The whole point of this article is that the bodies create the connection of the frame. The arms and hands just happen to be between the bodies when the connection is made. The arms and hands act as shock absorbers between the two bodies to create a smooth moving two-headed four-legged animal. The difficulty is maintaining a consistent connection while transitioning between the three point frame to the solo position and back to the three point frame. The hand and arm actions by themselves just don't work very well. The body must be the motivating force for the frame connection.