Discussion, Thoughts, and Interpretations on the Shoulder-in

 The shoulder-in is one of the most useful exercises in dressage, but is often quite difficult for students to ride correctly. It was first developed by the Duke of Newcastle on a circle and then later described by François Robichon de la Guérinière in his book Ecole de Cavalerie in 1772. He is most often credited as the father of this exercise and he states “This lesson produces so many good results at once that I regard it as the first and the last of all those which are given to the horse in order to make him develop complete suppleness and perfect freedom in all the parts of his body.” Steinbrecht is clear to give the Duke of Newcastle credit in his book ‘The Gymnasium of the Horse’ where he writes, “It is to the great credit of the old French master and writer Guérinière, and has made him famous, that he recognized the great importance of this school, has perfected and left it for posterity in his work under its present name with a clear, convincing description. However, its actual inventor or discoverer should be considered to be the very famous, unexcelled Duke of Newcastle who achieved his extraordinary successes easily and naturally with the particular characteristic of this movement, namely the forward directed shoulders and the correct weight on the inside hind leg.” Of all the books, I think Steinbrecht does the most thorough description and explanation of this exercise and it’s worth taking the time to read his work carefully.

 The shoulder-in, very simply put, is the bend of a 10-meter circle taken on a straight line (although the exercise can also be ridden on a circle). It can be done in either a 3 track where the inside hind leg lines up with the track of the outside front leg or a 4 track where each hoof has it’s own track. Too much angle in a shoulder-in will cause the exercise to lose it gymnastic effect for the horse. The horse should step under his center of mass with the inside hind leg. As a result shoulder-in creates flexibility and carrying power (assuming the horse is working in an uphill posture) in the inside hind leg while also allowing for freedom in the outside shoulder. Shoulder-in can be particularly beneficial to help create flexibility in the stiffer, pushing hind leg. For example, if you have a left bended horse with a pushing left hind leg, shoulder-in to the left will help the horse to step under and carry more weight with the left hind which will in turn increase the flexibility and carrying power of that leg. It will also create lightness and freedom in the right  (outside) shoulder, which is most typically the dominant foreleg in a left-bended horse. Shoulder-in can be ridden in all three gaits, but no more than a 3 track angle in the canter because of the 3 beat footfall of this gait and the inability for the hind legs to cross. However since most horses will tend naturally to a slight haunches-in position in the canter, riding subtle shoulder fore or shoulder-in can be beneficial in helping them develop flexibility and carrying power on the inside leg in the canter. For this reason, shoulder-in in the canter is often more difficult than haunches-in.

 In the aids for shoulder-in, the horse is bending around the inside seat and leg. An indirect outside rein against the neck can help to create the angle and bring the shoulders off the track. I often think of using my outside rein softly toward my inside hip. However, always remember the horse needs to maintain a bend in shoulder-in so the muscles on the outside of the horse’s body must be longer than those on the inside and therefore the rider must be cautious not to have so much outside rein that you block the bend. This is a very common pitfall in this exercise. You must allow the outside of the body to stretch and bend around the inside seat and leg. The inside rein should be fairly passive, but will remind the horse to have inside flexion at the poll and if necessary can work indirectly to prevent the horse from falling in. Another common pitfall is that students use too much inside rein and overbend the neck, creating a sort of ‘neck-in’, losing the nice subtle bend that should happen from poll to tail. The horse’s nose should be in alignment with the center of his chest and should never be more to the inside than when it is lined up with the point of his inside shoulder.

 In terms of body position for the rider, your shoulders and hips should be aligned with your horse so you should softly open your inside shoulder and look up towards the opposite corner of the arena or think of looking through your horse’s ears along a diagonal line if that helps. This will put your inside shoulder slightly back and your outside shoulder slightly forward (aligned with your horse’s shoulders). Make sure that even though your shoulders and eyes are along the diagonal, visualize a compass in your belly to direct the horse to stay on the track. Your inside leg is at the girth and your outside leg is slightly back. Like your horse this will put your inside hip slightly forward and your outside hip slightly back. If you horse does not want to step under well with the inside hind leg, the whip can be used softly on the inside hindquarters to encourage the stepping under, but avoid bringing the inside leg further back (another common pitfall) .

 If your horse drifts off the track toward the center of the arena when you are asking for shoulder-in he/she is not bending around your inside seat and leg well enough and may be falling on the inside shoulder. Even though the shoulders are carried toward the inside in a shoulder-in, you should feel as if the withers are lifting towards and filling up the outside rein, only then will the exercise serve to be of gymnastic benefit. Keeping the center of mass in balance is critical so you can softly scoop up the wither with a little inside indirect rein if necessary. Only when the horse lifts up through the withers, lengthens the muscles on the outside of his body, and fills up the outside rein will his thoracic sling be lifted. Then you should feel the freedom in the outside shoulder and a softness and lightness in the movement of the front legs will arise because the horse will be carrying a little more weight behind.

 One of the most confusing things about this exercise, it that the aids are described differently depending on the source. A number of classical instructors (past and present) discuss the outside seat bone when describing shoulder-in. In my studies this, quite frankly, was very confusing to me.

 Steinbrecht wrote: “Since in this movement, the bending inside leg simultaneously drives sideways, it is obvious that the horse, by yielding from this doubly strong aid, will try to escape the flexion by falling out with its hindquarters. The rider must therefore produce the correct opposition to his inside leg by well-adjusted use of outside rein and leg to keep the pace regular and not let it degenerate into falling sideways.

In the shoulder-in the rider must therefore often work more with the outside rein and leg and even put his weight more on the outside so as to always remain in control and be able to determine the degree of sideways travel of the horse’s outside legs, because the correct and unforced stepping over of the inside hind legs primarily depends on this.”

 Nuno Oliveira wrote: “Start turning a corner, having made sure that the horse is tracking correctly. At the moment when the horse enters the turn, the rider should turn his inside wrist, fingernails upward, towards the horse’s outside shoulder. The rider’s inside leg must stay by the girth, above all never going farther back. The weight should be on the rider’s exterior buttock as the outside leg acts softly but firmly, a little father back than the other leg in order to keep the incurvation and degree of obliquity required for shoulder- in.

 Anja Beran states: “Ideally, you should imagine that your seat leads the horse into the shoulder-in, in that you guide the forehand inward and then the outside rein catches the horse while your inside leg drives softly sideways. Under no circumstances should you think about pushing the hindquarters to the side. That would be backward. Above all, you must be speaking clearly to the horse so he doesn’t misunderstand and that you sit in the direction of the movement. This means sitting to the outside in the shoulder-in. In this way, the horse learns from the beginning to always follow your weight, and you can use this subtle hint from your seat constantly without the observer noticing it.”

 I was always taught that the weight should be on the inside seat bone, allowing for the horse’s spine to bend around it so although I now feel I understand what these masters are writing, it initially seemed backwards to me. For me, what has been the most helpful is not thinking about sitting on one seat bone or another as I often find this causes students (or myself) to collapse or contort their torso, but to think about the biomechanics of the horse. What is critical for a shoulder-in to be correct is that the horse maintains a soft bend around the inside seat and leg. This means the muscles on the inside of the horse’s body will shorten slightly and the muscles on the outside of his body will lengthen. Only then, will you really get the freedom in the outside shoulder that is so beneficial from this exercise. The horse’s spine should softly bend around your inside seat and thigh beginning with a correct lateral flexion at the poll or more scientifically, the atlanto-occiptal joint which is where the base of the skull meets the first cervical vertebrae (atlas). This lateral flexion is created first from a soft yielding to the inside rein. The bend should then travel through the whole spine. This will cause a slight rotation in the processes of the vertebrae and the muscles on the outside of the spine to lengthen and also lift. In a recent biomechanics class with Jillian Kreinbring, she spoke of the horses back filling her outside seat bone. That’s when a light bulb went off for me. It’s not so much about sitting to the outside as it is feeling the horse’s back raise and fill up your outside seat bone. For sure, the rider’s outside leg may have to prevent the hindquarters from drifting out, particularly when this exercise is performed off the wall, but be careful of actually sitting to the outside as this often causes the student to go against the bend of the spine and the movement of the exercise, which is incorrect. I also find because the rib cage is slightly swinging to the outside to allow for the bend even though you are on a straight line, you will feel the back muscles fill up your outside seat and the rib cage fill up your outside upper thigh so that your outside leg as a whole softly creates a boundary to prevent the horse from drifting to the outside and receives the bend created by the inside aids. The beauty in correct riding is that the rider and horse appear as one and the movements seem effortless to both horse and rider despite much balance and fine motor control required by both.

 In addition to work in riding, the shoulder-in can be performed in groundwork with a single line, in work in hand with reins, at liberty, or bridleless. Shoulder-in is often considered the best and most beneficial exercise in dressage. A well ridden shoulder-in is such a brilliant exercise for suppling your horse and it is the beginning of collection as the horse has to take more weight on the inside hind leg. Riding a truly correct shoulder-in requires a careful understanding on the part of the rider and a horse correctly educated in bending first. Taking the time to learn, understand and refine this exercise will pay dividends in the long run.