Horse spooks are as much a part of riding as the trot is a two-beat gait. That's something you can't change (and probably wouldn't want to--or you'd be riding something more predictable, like a bicycle). You can, however, go a long way toward understanding, deflecting and managing most blowups and spooks with leg yields. And when that awful moment arrives when you can't--well, I have some tips for handling those situations, too.
The Key to the Problem
The key to managing your horse's blowups and spooks and minimizing their damage to your performance (and composure) is having him on the aids. By "on the aids" I mean he feels relaxed, willing, and rhythmic; he's creating energy with his hindquarters; his back is round and swinging; his hind legs are stepping well under; and his neck and head are stretching forward into the bit and giving you a soft, confident, relaxed, "conversational" contact.
Here's a straightforward exercise that will help you put your horse on the aids (and confirm that he is on them), and that will also give you a reliable quick fix when he does "do his thing." It's leg yielding, which is more basic than shoulder-in but just as effective for dealing with blowups, especially when you realize you can leg yield anywhere. A couple of steps of leg yield may be enough to restore order and get your horse moving off your seat and leg and responding softly to your hands again.
Exercise: Leg Yield
Photo 1. To prepare Lugano for the leg yield, I turn early, bend him slightly at the poll, and straighten him through the neck and body, so he's parallel to the long side I feel his right hind come off the ground, I increase pressure behind the girth with my right leg...
Photo 2. ...and he crosses his leg to the left. My left leg on the girth keeps his haunches from swinging left and...
Photo 3. ...encourages him to take a big step forward in the next stride.
Photo 4. Leg yielding on the long side, I position Lugano by bringing his forehand a stride inside the track, almost as if I were going to cross the diagonal. My eyes, shoulders, and seat "look" straight up the rail, and so does Lugano's right hind leg as it crosses over.
This article is excerpted from "Fix That BLOWUP!" in the May 1993 issue of Practical Horseman magazine. For more professional tips on coping with spooks and blowups, see Cooky McClung's "Bombs Away!" in the February 2005 issue.