The hinging and unhinging of the wrists that result from the swinging motion of the club.  This is different than “hand action.”

            the rate of change in velocity per unit of time or space

       the position of the golfer and the club relative to the ball and target

               The bone connecting the forearm with the shoulder.

            A line spanning from the left bicep to the right bicep and                 parallel to the ground.

         Being cognizant of your performance

       The midpoint between the shoulders

    The point between the feet that is vertically beneath the player’s center

   An outward pulling force resulting from a swinging club drawing a rotating body (club) away from the center of rotation (the swing’s center)

At address the elbow of the right arm is pointing downward.  Should that elbow begin to point less downward the upper arm and the forearm take on the position of a wing.  Anatomically it could be described as an “internal rotation of the upper arm combined with elbow flexion.”