The behavior will depend if the figure mesh is welded or not. If the mesh in geometry folder is welded then a vertex shared by two body parts is exactly the same and so any morph, deformer or bending applied to one body part common vertex will be tracked by the other body part just because it is the same vertex.
If the mesh is not welded each shared vertex are two vertices and deforming only one body part will break easily the mesh.

Stupidity also evolves!