Horse Illustrated Magazine

The opening rein is a specific rein aid that comes in handy under certain circumstances. English riders often use an opening rein to straighten a horse through a line of jumps or to cue their jumper for an upcoming tight turn. Western riders rely on an opening rein when introducing fundamentals like side-passing. But perhaps the most common application of the opening rein is to steer a green horse that’s freshly started under saddle.

Most green horses have trouble maintaining a straight track (path) and weave aimlessly. It’s particularly evident in an arena, where they cut the corners and seem unable to stay alongside the rail. Though a simple direct rein will pull the greenie back onto the straight track, it also creates a bend in the horse’s neck and body. Soon you’re zigzagging and weaving even worse.

In contrast, the opening rein helps hold the greenie’s head, neck and shoulders straight. Then your inside leg presses against his ribs to push him back on track. In essence, you’re opening a door with your rein and pushing him through with your leg. Now doesn’t the term “opening rein” make sense?

Here’s a look at how to use an opening rein correctly. The green horse should be outfitted in some sort of snaffle bit, not a leverage (curb) bit. In this scenario, the horse is tracking left.

1. Make sure you have steady, even contact with a rein in each hand. You should be able to feel your horse’s mouth through the reins without restraining his forward movement.
2. As your horse begins to drift off the rail and toward the center of the arena, move your right hand away from your horse’s neck. Don’t raise or lower your right hand, nor pull it back toward your hip like a direct rein. Instead, think of the movement you use when opening a door: Your forearm almost pivots at the elbow.
3. While you hold your right rein in this position, press against your horse’s side with your inside (left) leg. If he ignores your leg pressure or seems unsure of your request, bump his side several times with your heel.
4. Remember that your horse should still be walking freely forward. Keep your aids and cues clear and simple. Your right opening rein is holding his front half straight and your left leg aid is pressing his body right, toward the rail.
5. You should feel your horse’s body shift over a few steps. Release your opening rein, continue walking, and then use it again if necessary. Once he gets the idea, you can expect more steering control even at faster gaits.

The opening rein may seem like a simplistic tactic, but it’s the foundation for even more advanced flatwork. Eventually you’ll create straightness in your young horse by using inside leg pressure to push him onto the outside rein. Mastering the opening rein will make it easier to graduate to that next level.

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