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“Lightness is like soundness; it can be a cover up, or the outcome of sound biomechanics” (jean Luc Cornille

In the last five days, a new study turned in his mind. He is comfortable with the subject but he cannot decide if he will places the study in the “meaning of life,” or “mechanoresponsiveness” series, or my thoughts. This morning as we were working, the guy next door dropped a large piece of metal. The man is a welder and sparks blew up all around. I spooked throwing my body to the left. As I was shifting my body, I felt a fly near my right thigh. He sprayed me with fly spray so the fly did not touch me but it was too close at my tastes, so I kicked with my right hind leg, but the fly was now around my left foreleg, so I threw my left front leg forward. As I was doing all that in motion, so I had to bounce a little higher. I did all the whole move keeping a very light contact on the bit. He laughed in his mind thinking, “Creativity in lightness. There is no question that you are the most qualified to write this study.”

I totally agree that lightness and soundness can be just a cover up. Lightness is not the bit. We can restrain our pressure on the bit in response to flexions of the jaws or hands action. We can do it contracting the neck, increasing the decelerating activity of the front legs, or many other restrictions. We have numerous ways to fake lightness even if we travel heavily loaded on the forelegs. Focusing on the bit does not teach us the coordination of our physique allowing the mastery of balance. The same can be said with muscle soreness. Manipulations releasing soreness do not address and/or correct the kinematics abnormality or dysfunction overstressing the muscle. Since in many instances, we can execute exactly the same move using different muscles, releasing one muscle will simply makes us switch protective reflex contraction and compromise. 

Lightness is the outcome of balance control and balance demands sophisticated management of the internal and external forces acting on our physique. Our limbs produce internal forces. Gravity, inertia and rider movements, produce external forces. Lightness commences with the decelerating phase of our hind legs. Some studies say that the decelerating or braking phase of our hind limbs last from ground contact to about 45% of the stance. Other studies say less than that. Since I am on the practical application of all the studies, I can tell you that the studies are both, right and wrong, as we constantly adjust the decelerating phase of our hind legs to the situation and the demand. During piaff for instance, we develop a considerable decelerating activity resisting forward displacement of our body over our forelegs. During collected trot, we adjust the decelerating phase of our hind legs in relation to our need for greater balance control.

After the peak vertical, which is the moment where our supporting hind leg is acting vertically onto the ground, we develop the pushing phase. Our hind limb is then under the croup and moving backward, propelling our body forward. The thrust generated by our propulsive hind legs is basically a force in the direction of the motion. The thrust generated by our hind limbs travels forward through our thoracolumbar spine, where it is submitted to the attraction of gravity. Our back muscles have the capacity to resist gravity converting a percentage of the thrust generated by the hind legs into upward forces. “An initial thrust on the column is translated into a series of predominantly vertical and horizontal forces which diminish progressively as they pass from one vertebrae to the next”. (Richard Tucker-1964). This is how we can regulate and reduce the load on our front legs. Previous theories, attributed to our abdominal and pectoral muscles, the core, the ability to flex the back. The theory was referred to as the bow and string concept and was created by L. J. Slijper in 1946. The theory was in fact attributing to the muscle supporting the work of our back muscles a function that is the task of our back muscles. The core helps in the flexion and other movements of our thoracolumbar spine but does not permit the sophisticated conversion of  the thrust generated by our hind legs into horizontal forces, upward forces and other forces.  

Our forelegs produce the greatest percentage of upward forces. During normal locomotion, 57% of the vertical impulses is created by our forelegs while only 43% is created by our hind legs. “In horses, and most other mammalian quadrupeds, 57% of the vertical impulse is applied through the thoracic limbs, and only 43% through the hind limbs.” (H. W. Merkens, H. C. Schamhardt,G. J. van Osch, A. J. van den Bogert, 1993).Our mastery of balance and therefore lightness on the bit, results for a great part from the sophisticated education and coordination of our back muscles. It is the work of our back muscles that reduces the load on our forelegs allowing our front limbs to propel our body upward and forward. When our back muscles are not adequately developed and coordinated, we are not capable to convert the propulsive thrust of our hind legs into sufficient upward forces and we have to compromise through different adaptations. Our forelegs are designed to propel our body upward and forward. We use elastic strain energy stored in our tendons, muscles, aponeurosis, and ligaments. We use the catapult mechanism of our biceps brachii and internal tendon. We use forces transported from the hoof up helping in lifting our trunk. We use tensegrity. We are quite sophistically designed for efficient locomotion. “The distal limb of the horse has been shown to function like a pogo stick, storing and returning energy in long, spring-like tendons throughout the gait cycle”. (Biewener, 1998Go; Wilson et al., 2001).However, when the load on our forelegs exceed their upward propulsive capacity, we have to compromise efficient locomotion and adapt to the load.

Our most common adaptation to excessive weight is using our front limbs as struts. Instead of propelling our body upward, as we are designed to do. We vault our body from one front limb over our other executing a long stride without suspension. This is a kinematics abnormality but curiously, there are equestrian specialties who regard this kinematics aberration as the finality of their education. We end the forward swing of our front limb normally extending the leg above the ground. During this brief sequence, we stabilize our fetlock for impact, placing the maximum surface of one bone of the joint with the maximum surface of the other bone of the joint. We retract then the front limb down and back to ground contact. When we carry too much weight on the front legs, the full extension of our front limbs does not occur above the ground, as it should, but instead, the full extension of our limb occurs simultaneously with ground contact. I never experienced such kinematics abnormality as he always works me in balance, but Caesar believes that the kinematics aberation is the main cause for the arthritis problem that he does have with both front limbs in his older days. “I was unable to stabilize my fetlocks in the synarthrotic position prior impact because I was rushed forward, heavy on the forehand. Limb extension and impact occurred simultaneously. As I was unable to place my fetlock joint in optimum position for impact, I felt in many instances,  that my fetlock joint was not properly aligned straining tendons and ligaments. The discomfort was not limited to the instant of impact; the whole stance was effectuated off synchronization, stressing cartilages, subchondral bones as well as tendons and ligament.”

I enjoy the lightness of my contact on the bit and the softness of his fingers and forearms. I am light because I master my balance and I master balance because he taught me how to use and coordinate my back muscles. My education never focused on the bit, or my mouth, or my jaws. I learned how to convert through the back muscles, the thrust generated by my hind legs and other forces into forward movement and balance control. As I was and still learning, it was variables in the contact that I gave on the bit. This is part of our dialogue. He regards his hands as sensors. He perceives nuances in the contact that I give on the bit analyze the possible cause and make adjustments in his body to better coordinate my body. Caesar and my dear late friend Manchester told me about half halt. I did not know what half halt was because he never used it during my education. When Ceasar told me, “They use half halt to shift our weight back over our haunches,” I asked him how could you do that? Caesar responded, “I did not; we are not designed to do that. They believe that we enhance balance shifting our weight backward over our haunches. Even if in her 2002 PhD thesis, Sophie Biau wrote, (This notion that still in use today does not have any scientific meaning from the perspective of the equine biomechanics).  

The misconception altering the understanding of balance control and consequent lightness is in line with the false belief that the antidote of contraction is relaxation. We do not shift our weight backward, we convert, forward through our thoracolumbar column, the thrust generated by the hind legs into greater upward forces. The whole process starts with the decelerating phase of our hind legs. We do not increase the weight on our hind legs but we increase the duration and intensity of the decelerating phase. This is what we do when we prepare our body for a performance such as the flying change. Preceding a lead change, the higher-scoring horses increase their contact duration of the hindlimbs and decrease the length of step and time between forelimb impacts to prepare to execute the lead change in the succeeding airborne phase.” (N. R. Deuel, PhD: J. Park, PhD, 1990)

We naturally accelerate the stride after the change. The acceleration is moderate if we prepare our body efficiently during the stride preceding the change. At the contrary, the acceleration is greater as well as the weight that we excerpt on the bit, if we do not prepare efficiently our physique during the pre-change stride. Some of us, naturally figure that increasing the contact duration of our hind legs allows us to be better prepared our physique for the athletic demand of the flying change. Many of us don’t figure the subtle adjustment and never perform the flying change at the best of their talent, unless the education focus precisely on increasing the contact duration of the hind legs. 

This type of education cannot be done touching our legs. First the duration of the decelerating phase is faster than the speed of your feedback correction. The time you register the move with your eyes or feel it with your seat and legs, we are already into the pushing phase. The second fact is that a touch of your whip or legs will create the wrong reflex as we are conditioned to associate a touch of your whip or leg with greater propulsion. I just explained how we achieve balance control. As we are trained to control our whole physique as I explained, we easily figure that we can further our balance control increasing the decelerating activity of our hind legs. Caesar was trained in respect of the driving aids, forward syndrome and when I talked about the subtle orchestration of the back muscles, he looked at me as if I was an alien. He was conditioned to obey, not to think. He even resisted at first. I reminded him one of Albert Einstein thoughts; I don’t remember the exact words but the thought was, if you ask a fish to climb a tree, it will spend is life thinking that it is an idiot. Soon Caesar was ecstatic figuring how well he could refine his body coordination. In reference to Einstein quote, he told me one day. I can figure my body so well that I could almost climb the tree. If I knew that before I would have climb the tree instead of throwing my rider into the tree; he would have kept a better spirit and I would have enjoyed the view.

Our education needs teaching our mind to figure further efficiency of our systems. When we learn balance the way I explains, we can further our body control and figure subtler and more efficient coordination of our physique such as increasing our hind legs’ decelerating phase. I told Caesar that it will be a lot of work but a fascinating and intelligent and rewarding journey. I used Robin Skarma’s quote, “Change is hard at first, messy in the middle, and gorgeous at the end.” A few weeks later, Caesar came back from a training session thinking, “I am not at the end but it is already gorgeous.”

Chazot