Depending on whom you talk to, the open rein may be considered the "go to" aid, or the one rein aid with the bad rap. Many people move onto more sophisticated rein aids fairly soon in their riding process, convinced that the open rein is only for the young or the inexperienced.
The thing is, this rein aid is like the letter "a" in the alphabet. You simply can't start reading without knowing how it works and what it can do. Even when you become a fully mature, experienced reader, you can't just drop that letter in favor of all the others. It's always there, ready to be used in different ways, in a variety of circumstances.
And so it goes with the open rein.
What is the open rein?
It's the simplest, most basic rein aid we learn. It is of course useful in all the disciplines and with all types of bridles because of its primary effect, which is to invite the horse into the open space created by the rein action.
To open the rein, you simply move it away from the horse's neck, in the intended direction. Note that you don't pull back while you open. The pressure on the rein should be the same as it was when your hand was close to the neck. Your elbow should still be on your side as usual (i.e. don't open your elbow in the direction as well - no "chicken wings!"). The opening comes from your forearm as it moves away from the horse's neck.
The rein should be only 4 to 6 inches off the horse's neck. It doesn't need to open wide, or for you to take your hand to your knee (however tempting that may be at times). In fact, as you get better at opening the rein, you can reduce the distance from the horse's neck. Most advanced horse and riders can find the smallest open rein as useful as a wide one. Think maybe 2 inches off the neck as you progress in your balance and aids.
It sounds so simple, right? Just like the letter "a". Once you know the sounds (short and long a), you're ready to read every word it's used in!
Till you come across the more complicated words!
There's more to it than that.
So here's the thing with the open rein. Although that rein is fairly simple, it can't happen on its own. There have to be supporting aids that go along with it. So while you're working on the one rein, you have to coordinate your seat, outside rein and leg aids at the same time.
Otherwise, you will accomplish little. The only thing that happens if you use the open rein in isolation is that you literally turn the horse's nose in the direction of the pressure. He may or may not follow that pressure (has your horse ever moved in the opposite direction of the rein aid?). He may swing his neck in the direction and lose his straightness. He may also lose balance and engagement.
So in reality, the open rein isn't for the faint hearted!
When can you use an open rein?
Here are five common situations in which you could use an open rein to encourage better balance, throughness, impulsion and suppleness, depending on the situation. I'll start at the beginning for a beginner rider and horse, and then develop into more advanced use.
1. New Rider
The new rider clearly benefits from learning the open rein. As hand-dominated human beings, we are always pointing toward the objects of our attention. One of the most intuitive ways to learn to direct a horse is to essentially "point" with the rein. Open the rein to the direction you want to move in, and the better educated horse will comply.
However, you should also use your entire body and outside rein to support the open rein. Click here to read a detailed description of how the body and reins can work as one to achieve a turn from the whole body, rather than from just a rein.
2. Young or Uneducated Horse
The open rein is one of the first rein aids a young horse will learn, even if more developed rein aids are introduced shortly thereafter.
Used with the supporting aids from the rider's body, the open rein will teach the horse that pressure on the mouth translates into movement in a direction. It is an uncomplicated aid and naturally invites the horse to step into the opening created by the rein.
3. Straighten The Outside Shoulder
Does your horse have a tendency to "drop in" to the turn or circle? This means that when you turn, the horse cuts the circle toward the inside of the ring, thereby not really staying on the arc of the circle at all. You are lucky that your great seat can follow his trajectory, otherwise, you would continue on the circle (horseless) while he heads off somewhere completely different!
In this instance, the outside open rein can act as a correction.
A slight open rein on the outside will invite the outside shoulder to stay where it is and prevent it from falling in. In effect, you're creating some space to help encourage the shoulder to stay on the arc of the circle (straight on the circle). This is straightness.
You also need a direct inside rein (the rein that goes straight from the horse's mouth to your elbow, parallel to the horse's neck) as a support. This rein will also help to keep the horse's head from turning completely to the outside.
4. Invite Flexion
A mild open rein will invite the horse to turn his head just enough for you to be able to see the corner of his inside eye. That way, he will be looking in the direction of travel. Flexion is the beginning of softening of the poll, throughness and maintaining balance.
The inside open rein, coupled with an active inside leg, will encourage the horse to flex to the inside. You can also use an outside direct or neck rein (depending on if the horse is on a straight line or on a turn) to prevent overflexion to the outside. Flexion is the beginning of bend, so with the correct seat and leg aids, you can progress to bend as the horse becomes more educated.
5. Shift Weight To The Outside
This is the most complicated use of the open rein, and follows flexion.
Using an inside open rein (and outside rein as described above), and an active inside seat bone and leg, you can actually ask the horse to step out, away from the opening rein. This can be very helpful when you want to shift the horse's weight off the inside shoulder, and initiate a flexion or bend at the same time.
It also allows the horse to learn to step straight through with the inside shoulder rather than fall in or duck toward the middle of the ring (similar to #3 above, but focusing on the inside shoulder instead). A straight inside shoulder can be a big help when it comes to allowing the energy through the body - which means improved impulsion, throughness and suppleness.
I'm sure there are other uses for the open rein that I haven't thought of. Let us know in the comments below what your experience with the open rein is, and how you use it in your rides.
Finally! The Ultimate Rider-Centered Program!
