Dynamics
Perceived movement within a static composition, implied by the direction, angle, or relationship of its forms.
In practice
Dynamics is the sense of movement in something that does not actually move. Diagonal lines, tilted shapes, forms that seem to fall or lean, and elements cut off by the edge all suggest motion. A sports poster with a tilted photo of a runner and type set on a rising diagonal feels faster than the same content arranged in level rows. Dynamics sits at the opposite end of the scale from static.
Often confused with Motion Graphics
Dynamics is motion implied within a still image; motion graphics involves actual movement over time.
Try this
Arrange three rectangles level, then tilt them at different angles, and compare which version feels as if it is moving.