Below is a link to a super article by Jane Savoie regarding the leg yield. In watching various horse/rider combinations during my L Program education, I am realizing this is a commonly misunderstood and therefore improperly ridden movement. The leg yield, along with lengthenings of stride, develop the thrust(pushing power) that is necessary at First level, and is a prerequisite to the carrying power required of Second level and beyond. It teaches the horse to adduct with the inside hind leg, knowledge he will need when you begin to develop the shoulder-in. Only when the horse learns to keep the inside hind leg underneath its center of mass will it then learn to lower that inside hip, which will allow him to develop the carrying power necessary for collection and cadence. Well ridden, with a nicely filled outside rein and a high degree of submission to the inside leg, this is also a super suppling and submission exercise for more advanced horses. Be creative: leg yield away from the rail, or, leg yield in one direction, straighten, and leg yield back, in a zig zag. This should provide you with an excellent clue as to which hind leg your horse can better adduct, valuable information for future development of straightness. You can also, when encountering resistance to the outside rein, turn that into a counterflexion and ride leg yield with nose to the rail. Keeping the distance covered in each direction symmetrical will also create muscle balance in your horse, and you. Start with a little and develop your horse's suppleness over several requests. But don't forget, forward before sideways, so never allow your horse to fall sideways. If the shoulders begin to lead too much(and anytime it is more than you decided, it is too much), half halt on the outside aids-more leg than rein. While the crossover of the legs is the essence of the exercise, do not sacrifice the thrust this exercise creates for the sake of sideways motion. Your horse's feet should not drag or create dust, and when you complete a well-ridden leg yield, you should feel your horse bounce lightly into your outside rein and carry forward with a nice cadence for at least a few strides. Scroll down to the bottom of this blog and find a picture of Anvil's Rethel, a rare white dun Norwegian Fjord, at just this perfect moment after a leg yield to see the beautiful cadence he has carried forward from the exercise. A well-timed subtle pet with the inside hand will reward your horse for this higher degree of balance, engagement and self-carriage, reaffirming that lightness we all seek. Enjoy!