Recently I`ve had a theme flowing through my lessons, where I`m trying to encourage my riders not to pull back on the inside rein. I`ve often told riders to feel like they`re indicating with the inside rein, and it`s a forwards movement akin to opening a door away from you.
But anyway, I have a more succinct and elaborate analogy and explanation now.
The reins support the shoulders. That doesn`t mean that you bring your hands so close that you trap the horse`s shoulders in a narrow triangle. It means that the reins act as guides for the horse`s neck and shoulders.
Often when people are riding a centre line I tell them to imagine their reins are creating a tunnel for the horse and then the leg pushes the horse down the tunnel. Reins should be of an even length and even on each side of the wither.
Now we`ll think about applying the same theory when turning. If you open your inside rein you create some empty space by the inside shoulder. The horse will want to fill this space. Then by closing the outside rein against the neck you are encouraging the horse to move his shoulders to the inside, thus enabling him to turn.
This has many benefits in that it teaches the rider to ride the outside of the horse; the horse learns not to fall out through his shoulder and so steps under more with his inside leg; and the horse has a more uniform bend through their body so stays in better balance.
For some, this makes perfect sense, but I`ve found it really useful with riders whose horse tends to look out and fall in, especially on circles. Today, for example, the gelding I was teaching with falls in on the right rein. So I asked his rider to check that she had created a tunnel down the long side for him and that he was straight there. He was, and when he became straight his stride opened up because energy flows more efficiently in a straight line, rather than round corners (think of a flowing stream). However, my rider lost this straightness around the bend. I suggested that she thought about the inside rein supporting his inside shoulder, to stop it falling in, by closing towards his midline. When the inside leg was applied, the horse changed his bend and balance to fill the outside rein, which hadn`t changed, and he no longer fell in around the corner. Obviously when the horse improves his suppleness and bend to the right, the inside rein can take a step back and not be quite so supportive.
Another element of this that you can think of, is that the rider is creating a box for the horse`s forehand with their reins as the long sides and bit and gap between the hands as the short sides. The box needs to stay rectangular – i.e. no widening of the hands – but when you want to turn left or right, imagine moving the box left or right. It should help keep a consistent contact and even rein pressure, as well as the outside rein looking after the outside shoulder and stopping the horse falling through it.
Some people fall into the habit of closing both reins together, but you want to think of it as more of an airlock. In order to close one rein (or door) you need to open the other rein, otherwise the horse will feel trapped and unable to go forwards. Or you can imagine you have a rod between your wrists. One hand cannot move without the other moving too, and then you will maintain the same amount of space for the horse`s forehand.
When I`m doing lateral work I will open the outside rein to invite the horse to move into it, but if they move over too much then simply moving the reins back over can straighten them subtly, and without causing them to wiggle and become more crooked. You can also control the amount of sideways by the amount of space you give the shoulder.
This way of thinking verges on neck reining, except that when necessary you can use each rein independently! Make sure you feel that your reins are providing support and guidance to the forehand and not pulling the head about. The mere pressure of the cheeks of the bit will cause your horse to adjust his position and alleviate the pressure. Then, when he is straight, the bit and the contact should be neutral.