A means of controlling a horse mostly used in western riding.
For most of history, horses were controlled using the two reins
independently to indicate which direction you wanted the horse
to go. Of course, in the old west , this caused a problem
becuase you might need a hand for say, shooting or roping . And
you know, training your horse to repsond to leg pressure is just
too much work I guess. Insert neck reining. So basically what
you do is train the horse to respond to the pressure of the
reins on the neck. The reigns are tied in a knot so it kinda
forms a loop. To move the horse right, you move the reins to the
right so that the left rein falls against his neck. When the
horse feels the rein on the left side of his neck, he is trained
to move away from it, hence he goes in the direction you want.
And there you go, one handed control with very little pressure
on the mouth being invovled. And now you know.