Series: Equine Biomechanics and the Timing of the Rider’s Aids, Part 4

This is the fourth in a series of posts. Check out Parts 1-3 if you haven’t already!

Part 1: Introduction

Part 2: How do I know where my horse’s feet are?

Part 3: What might we ask of the horse at the walk?

Last time, we built on our understanding of the horse’s walk cycle to learn more about applying aids in ways that work with the physics and timing of that cycle to communicate our requests in a sensible, natural fashion. This week we are concluding that discussion and this series with a more complex request, that of the Leg Yield. The Leg Yield is a sideways-stepping movement and incorporates aids from the leg, seat or weight, and rein.

What might we ask of the horse at the walk…concluded!

To refresh, this was number five on our list of requests we can make of the horse at a walk: We can even ask him to step sideways under his body with one hind leg (let’s say the right hind) so that he moves with an almost-straight body towards the left, forward and sideways at the same time. You may recognize this as the movement called the Leg Yield.

In order for the horse to change the normal straight-forward trajectory of its hind leg, we have to give the horse’s brain a bit of time to realize the request we’re making, and then carry it out. This means that we must ask for the sideways motion of the specific hind leg (let’s say the right) precisely at the end of Phase 2, when it is still grounded, but before Phase 3, when it lifts off into the air.

Note:  Once the horse’s foot is in the air, any attempt to change its trajectory will cause a loss of balance. In addition, the horse is physically unable to respond immediately to a sideways-driving aid while his weight is still being supported by the relevant hind foot.

LEG AID: When your hip is at its highest or its rear-most point, apply your right calf to the horse’s ribcage at a point slightly (1-2 inches only) behind the girth. Immediately thereafter the horse’s right leg will leave the ground (Phase 3) and travel through the air (Phase 4).

If you give too strong a leg aid here, especially if your leg is too far behind the girth, you may actually push the horse’s whole hind end to the left. If this happens apply your previously passive left leg 1-2 inches behind the girth, and in the next crossing step, moderate your driving aid.

SEAT or WEIGHT AID: While Phase 4 is continuing, you may merely think of dancing or sliding both seat bones very slightly in the direction of the horse’s left shoulder. 

This mere thought will cause your body to respond very subtly but quite clearly enough to be felt by the horse’s highly attuned sensory nerves. Be careful not to degenerate into “hula-ing” in the saddle. This movement should not be visible to an on-looker.

REIN AID: In addition, when you feel the horse’s right hip dip as he swings his leg sideways under his body, you have two beats (his right foreleg steps, then his left hindleg) before his leftforeleg will need to take a step. 

At this point if the horse has lost his balance even slightly, or is succumbing to the magnetic influence of the fence, rail, or track, he may begin to fall slightly over his left shoulder. To prevent that tendency, you will take a bit more feel of your left rein – possibly as much as a half-halt if the horse really is falling out to the left – just before his left foreleg leaves the ground (the end of Phase 2 for that leg).

Be careful not to pull the horse’s nose or neck to the left; he should be very slightly positioned to the right at the poll throughout by your soft inside rein. His body remains straight throughout.


Good riding is like ballroom dancing: the timing of invisibly communicated signals allows each partner to stay in step with the other while maintaining good balance at all times. Knowing how your horse’s body functions biomechanically is critical to developing your own skill in timing your aids so precisely that only a soft touch of your body on the horse’s results in the horse willingly and gracefully carrying out his steps in the dance. 

As riders with brains that are larger than our horses’, it’s our responsibility to learn to speak the horse’s language by communicating with him in a way that is clear and which builds his confidence in his ability to do what we ask. His God-given generous nature allows us to sit on his back; if he did not trust us he could (and will!) easily dispose of us. That trust is a great gift, slowly given and patiently built, and it can be quickly damaged or even destroyed by a careless, ignorant or willfully insensitive rider.

If you want to earn and keep your horse’s trust, learn the skill of precise timing and dosing of your aids. Your horse will reward you with his love and devotion. That’s true partnership!