ĒThe true rein contact of the trained horse is produced by the direction of the entire body, the neck in relation to the back, the back vis-ŗ-vis the haunches, so that the horse has to collect himself through the coordinated increased effects of hand and leg, and conversely to stretch his muscles and joints equally gradually upon a decrease in the aids of the rider, without interrupting the flow of the motion, without swaying, and without suddenly losing his balance.Ē
B.v.Oeynhausen (1852, 63, translation: TR).
Learning to establish and maintain a correct rein contact is one of the big difficulties the student encounters in learning how to ride. One of the reasons is that every novice initially thinks the rein contact is an issue between the rider's hand and the horse's mouth. As long as the student applies this approach, he will be unable to establish a good contact. In reality, the issue is much wider than that. Contact goes beyond rein contact and encompasses the horseís entire body and the riderís entire body. The horse's flanks have to make contact with the rider's calves, and the horse's back has to seek contact with the rider's seat. The horse's entire spinal column has to stretch into the bit that the rider's hand presents. And, not to sound sentimental, the horse's mind has to seek the contact with the rider's mind.
When the rider gets on his horse, he should begin by adjusting his seat. The legs are placed in the correct position, the pelvis is aligned properly, and the shoulders are brought to rest on top of the seat bones. The rider then activates the hind legs with either his inner thighs, knees, or his calves and whip and immediately adjusts the rein length so that he can feel each hind leg in his hand on the same side. The well toned back and abdominal muscles connect the riderís aids with each other, they connect the riderís body with the horseís haunches and the bit, and they connect the horseís hindquarters with the front end.
The connection between the riderís elbows and hips that is established with the help of the abdominal and back muscles enables the rider to feel the horseís contact with the bit in his midsection. The reins feel, then, as if they were a part of the riderís forearms. The energy impulse that emanates from the horseís hind legs and is passed along the horseís spine, through the riderís midsection, along the horseís top line, through the poll and to the bit, is received by the hands and recycled through the elbows by the abdominal and back muscles towards the hindquarters. The hands will feel as if they had become a part of the midsection as well. Anything the rider does with his midsection will be transmitted, supported and amplified by his hand. The hand becomes a link in a chain, a messenger between the rider's seat and the horse's mouth. Conversely, any rein aid the rider gives will be backed up by his body weight. That way, one can say that rein aids are converted into weight aids, leading to an increased weighting of the leg they are targeting. The rider's midsection is the control center, the conductor in the orchestra of the aids, that coordinates all the rider's aids and determines to what extent the aids "come through", i.e. to what degree they are successful.
There is an inverse proportionate relationship between the strength and effectiveness of the core muscles (midsection) and the peripheral muscles (forearms/hands, and legs). The higher the muscle tone in the midsection, the lighter the rein and leg contact can be. The weaker the midsection, the more the hands and legs automatically try and compensate with muscle strength. Put differently: a rider with a weak midsection tends to grip with his hands and legs. Conversely, a rider who communicates effectively with light hands and legs must have a firmly toned abdominal and lumbar musculature, supple hips, and an elastic but firm connection between the flexed elbows and the pelvis.
If the midsection is too wobbly, it becomes like a Black Hole. It swallows every incoming energy impulse and every aid, but passes nothing on in either direction, i.e. it does not transmit the horseís thrust forward toward the bit, and it does not transmit the seat and rein aids backward into the hind legs. Stiff hips block and interrupt the energy flow.
In addition, the riderís hands can only be steady, light, and independent, if they are anchored by the core muscles and thighs, like the branches of a tree are anchored by the tree trunk and the roots. Without this support of the riderís body weight the hands will always be stiff and heavy, and the effect of their aids will be limited to the horseís mouth. They get stuck in the poll, the throat latch, or the neck, because the rider's back (and the horse's back as well) does not transmit any energy impulses from the hindquarters to the front end and vice versa. There can be no connection through the horse's back, if there is no connection through the rider's waist first. The rider has to lead by example in this respect as well.
A heavy hand is by no means limited to a hand that pulls back or that holds a heavy weight. A hand that holds too long without releasing is heavy as well, even if the contact itself amounts only to a single ounce. A dead rein contact, as opposed to a live, communicative rein contact is heavy - even if it amounts only to a single ounce. If the rider's seat is weak, the horse can furthermore bind the hand by leaning on it, which never fails to further unbalance the weak rider.
If the rider's seat is balanced and secure with a strong midsection, the "power is plugged in". The rider feels that his seat bones are connected not only towards the back, with the haunches, but they are also connected towards the front, with the bit. By the same token, the hands are connected not only towards the front, with the bit, but they are also connected towards the back, with the hind legs. This makes it a little more explicable how the rider is able to affect the rein contact with his seat bones (and legs) and the hind legs with his reins. The rein contact becomes lighter when the calf loosens the hind leg up off the ground, thus withdrawing the support base for any leaning onto the bit. The hind legs will bend more in their upper joints, when the fingers close briefly around the rein for a half halt.
A rider with a strong midsection will not be pushed out of the way, no matter how hard the horse may pop up his croup and thrust against the rider's seat. As a result, the horse's haunches will give in sooner or later. The horse's back finds the necessary support in the hind legs and starts lifting and swinging. The horse begins to develop a strong top line from tail to ears.
Everybody can experiment with this. If you go limp in your midsection, you will find that your horse starts leaning on your hand, because he is rapidly losing self carriage, especially if you collapse forward. If you tighten your midsection and align your shoulders, seat bones, and heels in a vertical line, you will feel that the horse is regaining balance/self carriage, which translates into a lighter rein contact.
The horse has to meet similar requirements as the rider, in order to establish a good connection and contact with the bit. There are two main obstacles that can stand in the way: stiffnesses that block the energy flow and false bends that are like leaks in a garden hose.
These explanations demonstrate that the development of a good connection and rein contact demand of the rider to be strong and well connected in his core muscles, while being supple and soft in his peripheral muscles. The horse must be freed of all stiffness in his body, and false bends anywhere in his body must be prevented. One could even define connection as the result of the absence of stiffness (energy blockages) and false bends (energy leaks).