BILL—“Head’s up, heels down!” sticks in the mind of every rider of a certain vintage as the title of a C. W. Anderson horse book and as a phrase that was shouted constantly by beginner hunt seat instructors for decades. If you grew up riding in that mode, then it must seem blasphemous to see dressage riders ignoring it. So let me go on record as saying you should not try not to put your heels down!
At the same time, the act of having them down won’t solve all your leg position problems, and depending on how you put them down, it might actually make things worse. Bear in mind that this “heels down” mantra originated in a jumping context with short stirrups and a prescribed knee grip. Equitation riders were encouraged literally to jam their heels down and to press the inside of the ball of their foot against the iron, cocking their toes outward and showing a bit of the sole of their boot to a watcher from the ground.
Even now I will see a rider who is new to dressage stand in her irons and force her heels down to adhere to that old image. But, hold it, we DON’T want knee grip and a stiff ankle that pops you out of the saddle like squeezing a bar of soap in the shower! We want relaxed glutes, an open and enveloping seat , and legs that hang parallel like the sides of a croquet wicket—not pinched at the top like a clothespin. And, while your heels should be lower than your toes, you should accomplish that by lifting the latter rather than by depressing the former. Keeping the heel lower than the toe lets your calf feel firm and not flaccid on your horse’s side.
The leg adjustment a dressage rider makes is somewhat reminiscent of shrugging your shoulders—except you shrug your hips. Or this image: the rider lifting, opening, and then letting the thighs drop. Something like the frog kick of a breast stroking swimmer which lets your weight settle unencumbered onto your seatbones while the calves wrap softly around the horse’s barrel.
The stirrup iron only carries the weight of the rider’s lower leg which, as Sally Swift described in Centered Riding, allows the stirrup leathers to be so minimally stressed that they could be made of crepe paper.
The rider’s toe should point in the same direction that it does when you’re on the ground walking normally, in other words, neither angled unnaturally out in the 1950s hunter fashion or unnaturally twisted inward to point absolutely straight ahead.
For dressage heels, relaxation, elasticity, and an un-forced natural feel are keys.