The ability to react and change body position, with maximum rate of force production, in all planes of motion, and from all body positions during functional activities is

The ability to react and change body position, with maximum rate of force production, in all planes of motion, and from all body positions during functional activities is quickness.  How quick one can assess visual, auditory, or kinesthetic stimuli and provide the appropriate physical response denotes his quickness.
Other parameters for measuring performance are agility and speed.