When your horse travels downhill, he lifts his back and reaches his hindquarters far beneath him for support and balance. He also uses his abdominal muscles. Help him get into this position by not leaning far back in the saddle, says top trainer/clinician Julie Goodnight. "If you lean back while going downhill, you make it difficult for your horse to use his back well," she explains. "You'll also make your saddle slide forward, interfering with his shoulder movement."
Goodnight recommends a position somewhat like a two-point position. In a true two-point position, your legs are against your horse's sides while your seat is out of the saddle. For this two-point variation, you'll keep seat contact and roll your weight slightly forward onto your upper inner thighs.
"It's not necessary to do this move on slight inclines," Goodnight says. "For little hills, just sit up straight. But on a steeper hill, where your horse has to use his hind end for brakes and balance, this position will help to free up his back."
Avoid leaning forward, which could cause your horse to stumble forward and lose his balance. Instead, keep your center of gravity directly above the middle of your horse's back. (Tip: As a visual aid, align your torso with any vertical tree trunks you pass.)