I have been at a Clinic with Jean Luc Cornille at Ledingenäs outside Stockholm. Here comes my notes from the lectures during the clinic. The first day he had a lecture about the equine thoracolumbar spine and the second day about tensegrity. If you find these subjects difficult it might be easier to understand if you first read the notes from the clinic at my place in September this year.
Equine thoracolumbar spine
According to tradition you have been told that the spine swing and the back muscles stretch. New knowledge show that the back and the spine of the horse does not work that way. The traditional riding technic also tells you to ride the horse forward to engage the hind legs more and rebalance the horse with half halts to shift the weight backwards. But this does not really work. No matter how the horse is working the force always goes forward.
The stance phase of the hind legs can be divided into two different parts; the braking phase and the pushing phase. When the horse put down one hind leg he starts by braking (decelerating) with the hind leg. Then the body of the horse moves forward over the hind leg. When the hind leg is behind the vertical it starts to push. The balance in the horse i created by increasing the braking phase of the hind legs instead of moving weight backwards. Also in collection the weight is not really redistributed backwards, instead the hind legs brake more och the chest is lifted more.
When the horse is moving, this creates movements in the spine. The range of these movements are actually much smaller than most of us believe. The vertical movements does never exceed 53,1 mm. Although the movements are small, they occur in three different dimensions; laterally (from side to side), vertical (up and down) and rotating. The thoracic spine moves more than the lumbar spine. Often when you have a problem in the lumbar spine, the cause of the problem is actually in the thoracic spine. The movements in the thoracic spine also create a movement in the pelvic. If the horse is moving (bending) the thoracic spine more in one direction than in the other direction, the pelvic will also move more in one direction. That will influence the movements of one hind leg more than the other hind leg. Therefore the kinematic problems in the hind legs most of the times come from the thoracic spine.
All horses will protect the kinematic dysfunction that it has. If the horse has learned to move in a dysfunctional way, it will not change that way by itself. Instead it will try to keep these movements and try to protect the tensions that the movements create.
Stabilising system of the vertebral column during movements
The push from the hind legs always creates a force that goes into the spine of the horse. When the left hind leg is pushing the force goes diagonally forward and to the right and when the right hind leg is pushing the force goes diagonally forward and to the left. Without compensation, the force will just move the spine laterally (to the side) and the horse will start to move from side to side.
The horse has a lot of quite strong back muscles. The bow and string theory tell you that the horse should relax all these back muscles and lengthen them by engaging the stomach muscles. But this is not the purpose of the back muscles. The purpose of the back muscles is to stabilise the spine and protect the spine from movements that are harmful to the spine.
Between the vertebras in the spine there are muscles that are attached diagonally. The multifidus muscles goes diagonally in one direction (from the spinous processes of one vertebra backwards and down to a vertebra 3-4 vertebras further back) and the longissimus muscles goes diagonally in the other direction (from the spinous processes of one vertebra forward and down to a vertebra 3-4 vertebras further back). These muscles must learn to resist the diagonal force from the hind legs in order to keep the stability in the spine and in order to prevent the horse from moving from side to side.
The multifidus and longissimus muscles are the muscles closest to the spine. Above them are several other layers of quite thick muscles. Therefore you can’t influence these muscles by touching them. Instead you must influence them with movements.
The traditional way of looking at the movements of the horse and the function of the muscles is that the muscles either are contracting or decontracting. But that is not the issue. You will not solve the problem of tension by decontracting the muscles. It is instead a matter of coordinating the muscles. If a muscle is under stress, you should not try to decontract it. Instead the horse need to find a better coordination between the muscles, which will release the stress from the muscles.
A main component of muscle elasticity is a filament known as filament titin. Titin (also known as connectin) is a protein that is of great importance for the contraction of muscles. Within the muscle titin functions as serially linked springs that develop tension when stretched. There are multiple titin isoforms (variations) that vary in size and stiffness. This explains the elastic stiffness diversity across vertebrate muscles. Titin has multiple roles in striated muscles ranging from sarcomere assembly to mechanical roles such as providing the forces needed to maintain proper sarcomere integrity during contraction.
Guiding the horse to a proper coordination
There are approximately 344 hyaline-covered articular surfaces in the equine vertebral column. There is a very large elastic-stiffness diversity across vertebrate muscles. There is no chance that the rider will be able to coordinate all the articular surfaces in the spine, all attaching muscles and fascia. Instead this must be the responsibility of the horse. Therefore horse training is not about submission and teaching reaction of aids. It is about guiding the horse to find a good coordination of the back muscles and teach the horse to search for stability, effortlessness and easiness.
This is a new way of training the horse. Instead of putting the horse into a certain frame or shape, you should suggest a certain movement and let the horse try it. In the beginning the horse will fail several times, partly because it will protect the old movements and the tensions in the body. Never punish the horse for failing. Instead you should analyse the movement and suggest a different reaction. After a while the horse will start to find the right coordination for a few steps and then loose it. The more times the horse find the right coordination the more it will start to get the feeling of effortless movements and easiness. Since that feels good for the horse, it will try to return to that feeling and by time the horse will also learn to keep it for longer times.
The front legs of the horse will create a force upward, which creates a backward force in the riders body. The hind legs of the horse will create a forward force, which create a forward force in the riders body. There are therefore a lot of forces acting on the rider. If the rider have to much slackness, the riders body will start swing a lot. Then the horse must protect himself from these movements in the rider and the horse get tensed in the back muscles. A horse with tensed back muscles will start to push more and accelerate.
There is an expression ” Hands without legs and legs without hands”. That is stupid. You should never use the legs without the hands. Your fingers need to be relaxed to be able to feel how the horse is reacting.
Lateral bending and rotation
The rotation can be correct or inverted. With a correct rotation a right bended horse will have a tiny rotation towards the right. With an inverted rotation a right bended horse will rotate to the left. Then the left front leg will be more loaded. All horses are by nature a little crooked. They will then have more tendency to rotate to one direction (with both lateral bendings).
Every single vertebra rotate very little, but in a segment of vertebras the rotation get bigger. Especially this is true for inverted rotation. When the horse rotate correct, the rotation is quite small, but when the horse rotate inverted the rotation become much bigger.
The scientific word for the rotation is named by the direction the ventral part (the part that is facing the ground) of the spine goes to. When you are riding on the horse you feel the movement in the dorsal part (the part facing upwards) of the vertebra. When the dorsal part of the spine rotate to the right the ventral part of cause rotate to the left. In practical riding we call this a right rotation (the dorsal part of the spine is going to the right), but in science this is called a left rotation (the ventral part of the spine is going to the left). This is very confusing. To avoid being confused we continue to name the rotation from the dorsal part of the spine. But if you read a scientific paper you must be aware of the fact that they will instead name the rotation from the ventral part.
Lateral bending occur between T16 and T9 and rotation occur between T14 and T9. Therefore both the lateral bending and the rotation is best controlled by the upper thigh of the rider. You can not do this if you sit on your glute with your knees high. Instead you need to sit on your seat bones with your thigh as vertical as possible. You can never be totally on your seat bones. You will always have some support from both your glute, your seat bones and your upper thigh. But the distribution should be more on the seat bones and less on the glute.
The riders upper thigh is hugging the chest of the horse and that is what will help the horse to find the correct rotation. But the upper thighs are influenced by the back muscles. If the horse is having an inverted rotation and the rider follows this rotation, the rider will get a bending in the spine. Then the rider will not be able to sit straight with the upper thighs. Therefore the rider should never follow an inverted rotation. Instead the rider must keep a straight spine to be able to help the horse to correct an inverted rotation.
There are many ways to correct inverted rotation, but different horses will react differently. One method that works great with one horse will not work with another horse. That’s because the horse will protect the inverted rotation. If one method doesn’t work you must try another one.
What is tensegrity?
Tensegrity is not a new concept, but at the same time it is new in the biomechanics of the horse, since we now know more about it.
Engineering explains that the stability of a structural network is determined by
- The material properties
- Their arrangement
- The ”play” (free movement) in the joints that interlink the different elements
- Stability of the critical joints is often achieved by enlarging the amount of load-bearing material in the critical regions.
When weight is a consideration such as for a bridge, engineers have developed ”prestress” structures such as concrete beam with pre-tensioned steel bars placed in regions to take care of these strains.
Nature created biologic tensegrity placing the joints under tension providing grater strength for less mass. Nature engineered the horse’s legs and whole body for speed and jumping performance finding a way to combine light lower legs with strong propulsive power and capacity to absorb considerable impact forces. That’s why the muscle mass are situated higher up on the upper legs and the body of the horse. In the lower legs the structure consists mostly by tendons and ligaments. They therefore are light in weight, but strong, and can use the elastic energy and be part of the tensegrity in the horse.
Tensegrity, elastic energy, force transport and other engineering marvels have created the horse whose efficiency starts to be understood as never before.
Work with less effort
When the movements of the horse is created by contracting and elongating muscles, every movement takes a lot of energy to perform. If the horse moves in a certain cadence, frequency and coordination he can move in a more effortless way. When the horse discover that, he get interested in working with us. When the reward of the work is comfort, the horse starts to go even beyond what we ask for and maximise the performance in a way that at the same time minimise the effort.
We have to guide the horse in this direction. The horse will not find the right solution right away. But when the horse start to find the effortless way of moving, that will be one of the most powerful rewards you can imagine.
Most of the aids we are using when we are riding is actually punishing the horse. We are kicking the horse in the side or attacking him with the spurs. The horse need to protect himself against this. If we can guide the horse to move in an energy-optimising and more effortless way, we don’t need strong aids and force. Most riders has the dream of riding in a way that they do nothing, that the horse responds to the riders thoughts. What can make this dream come true is the use of tensegrity! When the horse is working with tensegrity, he will feel even the slightest change of muscle tone in the rider. Then the precondition for a good communication will be better balance control and core stability of the rider – not stronger aids!
Maximise the elastic energy
Power absorption is usually associated with eccentric contraction and power production is usually produced by concentric contractions. Power absorption can also be caused by elastic energy stored in tendons and ligaments. The subsequent power production originates then from the release of elastic energy instead of concentric muscles contraction.
We need to create a situation where the elastic energy is maximised. That is the only way to create effortless movements. The horse is constructed to bounce upwards. When the horse does not do that, he will only be moving weight from one front leg to the other. That kind of movement will bring lameness to the horse.
Forces can be transported through the limbs and body without power production by the transporting muscles. Power transport can take place during isometric contraction without power production by the transporting muscles. Therefore, no muscle fibers are needed to transport power and tendons can also transport power. Muscles spanning over more than one joint can transport power at one joint and simultaneously produce power at another joint.
Recent ultrasound-based measurements indicate that fascial tissues are commonly used for dynamics energy storage (catapult action) during oscillatory movements, such as walking, jumping or running. The long and stiff tendons in the distal limbs of the horse are able to store substantial amount of elastic energy.
The role of the fascia
A tensegrity structure is characterised by use of continuous tension and local compression. The simple joint is stabilised by continuous balance between tension and compression elements. The traditional thinking is that ligaments and tendons stabilise the joint and the cartilage assure the rotation in the joint. The model is no longer accurate. Cartilages are very thin and could not withstand the intensity of the impact forces during regulate gaits and never the less the landing of a jump.
Fascia, arranges in sleeves, wrap joints and keep bones apart as they flex. Under tension, fascia is strong enough to separate the joints creating a microscopic space protecting the joint.
Tension of the fascia is created by muscles work. Muscles leverage against the fascia to optimise tension for each movement to stabilise and prevent overloading of the joints. Fascia is light but resistant.
The horse will by himself figure out how much muscle work he need to create the right amount of tension for the fascia to function properly. But if the horse has to protect himself (for example from the rider) he will not have the ability to do this.
Stress, tension and injuries
If you go faster than the horse’s natural tempo or frequency, that will create stress on the structures and the horse need to protect himself. Horses create speed by stiffening the spine. Therefore you have to stay in the cadence of the horse.
The energy produced by normal walking would tear all the ligaments in the knee if it was not absorbed by muscular activity that are important for anteroposterior stability in the knee. Eccentric contraction dissipates energy to decelerate the knee immediately before the heel strike. Failure to decelerate the leg can generate forces as large as 65 x body weight.
The sacroiliac joint is a joint with two layers of cartilage. The joint hardly move at all. But the force travel through the joint in different direction. If there are movements in the joint it will be under stress and the horse has to protect it with tension and inflammation.
Communication between the rider and the horse
The traditional view of getting the horse to perform is that the rider use the correct combination of aids and that will make the horse perform the correct movement. In reality the combination of aids will only make the horse protect himself. The real conversation occur on a more sophisticated level. The rider need to use her own posture, tone and tensegrity to influence the horse in a certain way. If the rider start to tense, move, pull on the reins or kick with the legs, this communication will not work, because of the need for the horse to protect himself.
The classical equitation talks about a shift of the riders weight. With the knowledge we have today, we know that the rider must stay neutral the whole time. The rider should never act from back to front or from front to back.
There is an integrity of the whole body that has been completely missed by the equitation of the correct aids. Muscles never work alone and fascia connect the whole muscular system and support muscle function. Most of the length change required for the work of locomotion occurs not in the muscle fibers themselves, but by elastic recoil of the associated tendons and muscles aponeurosis.
The delicacy, the discretion, the finesse advised by the best were an incitation to an equitation of harmonic tensegrity where nuances in muscle tone replace the crude theories of hands, gestures, shifts of the rider weight, kicks of the legs and other coarse actions.
The integrity of the horses physique demands the integrity of the rider’s body.
Not one part acting, as taught by the equitation of the ”correct aids”, but instead the entire body playing with nuances within and overall integrity. ”I believe the true classical masters would embrace this information as a much better explanation of what they felt, but had only the language of their days available to them to use to explain.” – Patricia Cameron
Believes, misconceptions and scientific knowledge
We are no longer at the level of stretching and relaxation or elongating muscles to increase the range of motion. These theories have been the deal for centuries, but tissues do not function as theorised in the book.
We have been trained to believe that release and relaxation were the components of elasticity. Elastic stiffness does not fit our equestrian education for the simple reason that our equestrian education is based on literature instead of science.
Our ancestors explained what they felt and made theories that could explain their feelings. Therefore the classical literature are filled with misconceptions. That does not mean they were bad riders. But they could only explain their riding by the knowledge they had at that time. The concept of tensegrity is a much better explanation for what our ancestors felt.
Tensegrity is the explanation that the best of the best have hinted over centuries. Harmonic tensegrity is the new generation of equine athletic training.