What is leg yield and how is it ridden?

Leg yield is the simplest lateral movement in dressage, in which the horse moves both forward and sideways simultaneously while remaining straight or with very slight flexion away from the direction of travel — making it the appropriate introduction to lateral work because it requires the horse to move away from the leg without the additional demands of collection or bend that more advanced lateral movements require. In a leg yield tracked to the right, the horse moves forward and to the right while being very slightly flexed left at the poll — just enough that the rider can see the horse's inside eye — with the horse's body remaining parallel to the long side rather than bent around the inside leg as in more advanced movements. The horse's legs cross, with the inside legs crossing in front of the outside legs as the horse moves sideways, which is the primary gymnastic benefit of the exercise: the crossing action develops the inside leg's ability to step across and under the body in a way that begins the lateral engagement that more advanced collection work will require. The aids for leg yield to the right are: left leg behind the girth pushing the horse to the right, right rein maintaining the direction of travel and very slight left flexion through the inside rein, outside right leg available to maintain the pace and prevent the haunches from leading. The horse should travel on approximately a forty-five-degree angle to the track or the centerline from which it is being ridden, moving both forward and sideways in approximately equal measure. Common mistakes include the haunches leading rather than the shoulders, excessive bend rather than the very slight flexion appropriate to the movement, and too much sideways movement relative to forward — all of which indicate the horse is falling rather than genuinely stepping across with engagement.