Follow through and Overlapping

When a character moves, not all body parts move at the same rate. When a character starts moving from a stationary position parts of the character's body, such as the arms and head stay in stationary position for a few frames when the starts to move. The same thing happens when a character stops moving or changes direction. This effect creates an illusion that a character is obeying the laws of physics.

Here's an example I drawn of a man skidding on a wet floor to a ticket booth.

In this example, the character has skid to a stop, but parts of his body continue to move in the same direction as the character was moving before. If this was animated, this continulation of motion would last only a few frames.

An extreme example of this effect can be observed in fight scenes were a character gets knocked out or flune at a distance.

When a character moves, clothing and hair are dragged about. Sometimes this is animated in certian ways for dynamic purposes, demostrated in the anime-styled character below.

Fat or flabby tissue is also subject to this principle.