Still, all extended parts have some part that moves. Thus, internal rotation is characterized as internal motion of a body such that all extended parts include a moving part. This characterization only describes a relation between beginning and end. For the process view, the correspondence of trajectories of smaller parts of the rotating object can be considered. The third class of internal motion to be discussed includes body movements and, in general, movements of parts of an object while other parts do not move.
Bodily movements consist of movement of parts of the body relative to other parts.
That means that those parts change their location while the other parts stay at a location. Parts of a body may change their location in different ways. This is taken care of by the formulation of, since it does not specify the character of motion of the moving part. It is worth noting that partial growth and partial shrinkage is both, growth and partial motion or shrinkage and partial motion, respectively. Thus, the classes given here are not exclusive.