Mechanoresponsiveness 32
Mechanoresponsiveness 32
“You do not lead by telling people some place to go. You lead by going to that place and making a case.” (Ken Kesey)
Since centuries, classic authors have emphasized improving the equestrian art with the support of science, but it never went beyond integrating new findings to traditional beliefs. Everyone is talking about some place to go but no one went to that place and make a case.
We did; we questioned and upgraded classical school of thoughts to actual knowledge and we make a case learning how to apply new knowledge. When Leo Jeffcott measured the possible range of motion of the equine thoracolumbar spine in the dorso-ventral direction, “Thus the total range of movement in the dorso-ventral directions of the equine back was only 53,1 mm under these experimental conditions.” (Leo B. Jeffcott, Natural Rigidity of the horse’s backbone, 1980. Equine vet J. 1980, 12 (3) , 101-108) Quite predictably, believers of the swinging back questioned the experimental conditions. They felt a greater range of motion while riding and instead or asking why scientific measurements find a very limited range of motion while riding the horse induces a large amplitude of movement in our seat, they rather dismiss new knowledge and protect their core belief.
The response is that on the saddle, the rider feels the sum of the forces generated by the hind and front limbs and the thoracolumbar column movement. Our ancestors interpreted the sum of the considerable forces created by the limbs actions, and the minuscule range of motion of the horse thoracolumbar column as large movements of the thoracolumbar spine. Based on the misinterpretation, they conceived an equitation promoting relaxation of the rider’s back.
Years earlier, another discovery confused traditional beliefs. “Electromyographic studies and movements data presented above strongly suggest that the primary function of the back muscles during walking is to control the stiffening of the back rather that to create movement.” (Hans Carlson, Halbertsma J. and Zomlefer, M. !979, Control of the trunk during walking in the cat. Acta physiol. Scand. 105, 251-253) As expected, classical school of thought resisted the findings arguing that Carlson made the study on cats. While traditionalists protected their core belief, all the following studies confirmed that the fundamental principle of all terrestrial mammals, include the horse, was a muscular system protecting the thoracolumbar column from an amplitude of movement that would exceed the thoracolumbar spine’s possible range of motion.
The practical application of the two findings, leaded to reducing the forces induced in the rider’s back from the horse limbs, until matching the limited motion of the horse thoracolumbar spine. Instead of relaxation, the solution is supple resistance of our back and abdominal muscles. Interestingly. It looks like, promoting an “immovable” pelvis, the Duke of Newcastle intuitively figured centuries earlier, proper functioning of the equine back. “A rider’s body should be divided in three parts, two of which are mobile and one which is not. The first of the two movable parts is the body down to the waist; the other is the leg from the knee downward. Therefore, the immovable part of the body is from the waist to the knees.” (Duke of Newcastle, 1592-1676) Actual trainers promoting relaxation of the horse back are forty years behind actual knowledge and teachers promoting relaxation of the rider back are four hundred years behind.
Academic equitation regards shifts of the rider’s weight as a form of communication with the horse. “Undoubtedly any shift of the rider’s weight is important for balancing the horse for controlled movements.” (Estienne Saurel. !964. Pratique de l’équitation d’après les maitres français. Flammarion, Paris) In 1976, James Rooney described the back muscles as set in mirror image direction. Further studies demonstrated that from their insertion to their function, back muscles would be disturbed by any shift of the rider’s weight, back to front or front to back. The practical application of the three studies suggests an equitation based on a neutral balance and therefore a rider perfectly balanced over the seat bone and not acting with any voluntary or involuntary shifts of the rider weight or direction of the rider’s weight acting back to front or front to back.
Since the rider’s support are the seat bones, basic law of balance demands that the part of the rider’s body situated above the seat bones, the torso, as well as the part of the rider’s body situated below the sear bones, the legs, remain on the same vertical lines. The shoulders, the middle of the vertebral column, the seat bones, and the stirrups need to be on the same vertical line. The middle of the vertebral column came in the picture when dynamics studies demonstrated that even if the rider’s shoulders are exactly above the seat bone, the horse will feel the rider’s weight back to front when the middle of the spine, the junction between the kyphosis of the thoracic vertebrae and the lordosis of the lumbar vertebrae, is behind the vertical between the seat bones and the shoulders. As well, the horse will feel the rider’s weight front to back when excessive arching of the lumbar vertebrae places the middle of the spine ahead of the vertical between the seat bones and the shoulders. The middle of the rider’s vertebral column can be defined as the center of rotation.
Researches continued demonstrating that limbs and vertebral column movements were for a great part the outcome of elastic strain energy stored in the tendons and aponeurosis during the first half of the stride and used for the second half and the swing phase. “The elastic energy stored in and recovered from tendons during cyclical locomotion can reduce the metabolic cost of locomotion.” (Cavagna et al., 1977Go; Alexander, 1988Go; Roberts et al., 1997). Soon, it was revealed that muscles store and reuse elastic strain energy even in the absence of tendons. “Apart from the role of tendons and collagen in energy storage, the muscle itself stores and recovers elastic strain energy, as elastic strain energy can occur in the absence of tendons.” Microscopic tendons vibrate within the back muscles and they vibrate in chaotic fashion when the rider movement exceed the possible range of motion of the horse’s thoracolumbar column.
Even at microscopic level, the horse’s frequency or cadence is an important element of the conversation between horse and rider. “Because the muscle is composed of both muscle fibers and tendinous materials, all of these structures must be collectively ‘tuned’ to the spring properties for the muscle-tendon system to store and recover elastic strain energy during locomotion.” As simplistic equitation believes that forward movement can be created rushing the horse forward, the practical application of advanced research studies demonstrates that rushing the horse faster than his natural cadence stiffens the back muscles hampering the capacity of the back muscles of converting the thrust generated by the hind legs into upward forces, balance control, and horizontal forces, forward movement.
While simplistic theories pretend than greater amplitude of movement can be achieved elongating muscles, real science explains that elasticity is created within the muscles by large proteins known as filaments titine. “Titine functions as serially linked spring that develop tension when stretched. There are multiple titin isoforms that vary in size and stiffness. Which explain the elastic-stiffness diversity across vertebrate muscles.” (Paul C. LaStayo, PT, PhD. John M. Woolf, PT, MS, ATC. Michael D. Lewek, PT. Lynn Snyde-Mackler, PT, ScD. Trugo Relch, BS. Stan L. Lindstedt, PhD. Eccentric Muscle Contractions: Their contribution to injury, prevention, rehabilitation, and sport. Journal of Orthopaedic & sports physical therapy. 557-571. Volume 33, NUMBER 10, October 2003) Titine is functioning as a locomotor spring and therefore, it has to be tuned to the frequency of muscle use. Frequency is part of efficiency on locomotion and rushing the horse at a speed exceeding the horse natural cadence is rushing as well the horse toward lameness.
These simple scientific findings expose the difference between talking about science and upgrading riding and training principles to actual knowledge, “going to that place and making a case.” The practical application of advanced research studies opens fascinating perspectives, quality of life, performances and soundness. However, the practical application of advanced research studies is literally a paradigm shift. The practical application commences by upgrading riding and training principles to actual knowledge. One cannot hold to old core beliefs, (cognitive dissonance) and apply actual knowledge. Schools of thoughts integrating new knowledge to old theories are setting humans and equine athletes for failure.
Academic equitation believes for instance that balance is achieved shifting the weight back over the haunches. Actual knowledge exposes the falsehood of such belief. There is no backward weight transfer Instead, a horse increases the duration of the hind legs decelerating phase. “The present study’s finding of significantly greater duration of hind limb support, along with a consequently shorter swing phase, contradict previous reports that found no differences in these times between front and rear limbs.” (J. L. Morales, DMV, PhD – 1998) New findings contradicting old findings is the norm in equine research, by opposition to the equestrian tradition which want to believe that principles are forever true and irrevocable. Carl Sagan wrote, “In science, it often happens that scientists say, “You know that’s really a good argument; my position is mistaken” and then they would actually change their minds and you never hear that old view from them again. They really do it. It does not happen as often as it should, because scientists are humans and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.” And equitation.
Going to that place and making a case is applying pertinent discoveries for better education through better understanding of the physics challenging the horse physique. Leonardo da Vinci stated that in spite of a good painting technique, the artist who does not have a sound understanding of the human body is likely to paint muscles looking like a bundle of radish. We can repeat traditional views, submit the horse to the correct aids and win on a bundle of radish, or, we can upgrade our riding and training techniques to actual knowledge, develop and coordinate the horse physique for the athletic demand of the performance and win on a sound horse. Jean Luc Cornille/Science Of Motion®