PART I

Motion:
1) A proposal for action; Esp: A formal proposal made in deliberate assembly.  2) An act, process, or instance of changing pace: movement.  3) An impulse or inclination of the mind or will.  4) To direct by a motion.*

Symmetry:
1) Balance proportions.  2) The property of being symmetrical Esp: correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis.*

Symmetrical:
1) Having, involving, or exhibiting symmetry.  2) having corresponding points whose connecting lines are bisected by a given point or perpendicularly bisected by a given line or plane.  3) being such that the terms may be interchanged without altering the valve, charac­ter, or truth.  4) capable of division.  5) Affecting corresponding parts simultaneously and similarly.  6) Exhibiting symmetry in a structural formula.*

* Definitions above taken from Websters Collegiate Dictionary of Words

Example of a good golf swing/motion
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