To increase the suppleness of your horse, you can add lateral exercises to your work program. The leg-yield is an elementary lateral exercise, which can be performed at either the walk or sitting trot along the long side of the arena or across the diagonal of the ring, with the horse positioned at no more than a 45-degree angle from the direction in which it is moving.
If the horse begins by traveling counterclockwise, then performs a leg-yield across the diagonal of the arena, your aids are as follows:
- right indirect rein
- right leg behind the girth
- left leg at the girth
The horse's body remains straight during this movement, except for a slight bend at the poll, away from the direction of travel. Your right hand bends the horse only to where the bulge of its right eye can be seen, while your left hand restricts the animal from rushing. Both hands are shifted slightly to the left to reinforce the right leg as it drives the horse toward the proper direction of travel.
To keep the animal's body from becoming bent from withers to tail, your right leg must be positioned behind the girth. Pressure exerted by the right leg creates the lateral movement in the haunches, while the at-the-girth position of the left leg prevents the horse from bowing its barrel toward the direction of travel and helps to maintain impulsion. As in all lateral movements, pressure from each of your legs changes as necessary to maintain the proper position and impulsion.
If the horse begins by traveling counterclockwise, then performs a leg-yield along the railing on the long side of the arena, your aids would be as follows:
To initiate the movement, bring the horse's forehand off the track by moving both hands slightly toward the inside of the ring, while slipping your left leg back into a behind-the-girth position and applying enough pressure to make the horse take the first step sideways. The animal should continue traveling down the long side of the arena with its body at a 45-degree angle from the railing and its left legs crossing in front of its right legs.
The function of the hands is critical at the start of the movement. In the span of a few seconds, they must: (1) half-half the horse to balance it in preparation for the movement; (2) create a slight left bend at the horse's poll through a left indirect rein; (3) bring the horse's forehand off the track by moving together to the left; then (4) change the direction of travel by shifting to the right, creating lateral motion in conjunction with the left leg aid. Thus, there is a shift of the hands to the left, immediately followed by a shift to the right. This must be done subtly, or the horse's impulsion will be interrupted by the roughness of your hands.
If the horse tries to leave the track, your outside hand can be used as both a restricting aid and an opening rein for a moment or two, correcting the error by prohibiting forward movement while guiding the horse toward the proper direction. Your hands, then, change both their strength and position to make the adjustments necessary to maintain the leg-yield.
You may find it easier to perform this movement across the diagonal, since your legs remain in the same position as when your were traveling around the preceding corner of the ring; whereas, if you choose to perform the leg-yield on the rail, you must change the position of both your legs to initiate the movement.