While anticipation is the preparation of an action, follow through is the termination of an action. Actions rarely come to a sudden and complete stop, but are generally carried past their termination point.
In figure movement, actions of the parts are not simultaneous, some parts initiate moves, while others follow. For example, the wrist leads the hand and fingers in a gesture.
Weight and Drag
Appendages or loose parts of a character or object will drag behind the leading part of the object. Then as the object comes to a stop, the looser parts continue to move taking longer to settle down and stop.
Weight of the appendages dictates the speed with which they follow the lead, heavier objects drag farther behind. The lighter the object the smaller the drag and the quicker the stop.
Slight variations in the timing and speed of loose parts makes objects seem more natural. This overlapping action makes the objects and movement more interesting.
An action should never be brought to a complete stop before starting another action. Overlapping maintains a continual flow between whole phrases of actions.