02/25/2015
History of Equine Back Research Studies-Jean Luc Cornille
Since the inception of the Immersion Programs I have observed that going through the history of equine research studies has better helped riders, trainers and therapists to understand how the horse’s vertebral column effectively functions. This history affords the participants a greater accuracy as well as an evolution from the simplicity of past theories to the complexity of actual knowledge. Studying the past also reveals from where and when the theories, that are still promoted in these present days come from, and just how long it has been since they have progressed. This text is, of course, just a brief summary of the original lecture.
It is true that the fascicles of the main back muscles are inserted obliquely on the dorsal spines The fascicles of the longissimus dorsi muscles are oriented oblique, down and forward while the fascicles of the spinaleus dorsi and more exactly the multifidius, are oriented oblique, down and backward. Their action induces rotary forces on the dorsal spines and correspondent vertebrae. This was explained by E. J. Slijper in 1946. The Dutch scientist also described the horse’s vertebral column functioning as a “bow” that can be flexed by the action of the “string”, which is composed of pectoral and abdominal muscles. The theory was referred to as the “bow and string concept.” With some variables, this is basically the concept behind most actual riding techniques as well as the concept supported in the video that started the discussion. The problem is that the concept was presented in 1946. Scientific findings and therefore knowledge has greatly evolved since 1946.
In 1964 Richard Tucker explored the thought that acting on the dorsal spines, the back muscles were allowing the vertebrae to transmit the thrust generated by the hind legs into horizontal forces, (forward movement), and to create vertical forces resisting gravity and therefore permitting balance control. Tucker furthered Slijper’s description explaining how, through their insertion on the dorsal spines, the muscles were compressing the vertebrae against each other favoring forward transmission of horizontal forces, (forward movement.) Simultaneously back muscles are inducing rotary movements of the vertebrae creating vertical forces, (resistance to gravity and balance control.) Tucker moved away from the simplistic idea that the thoracoumbar column was flexing and extending as a whole. The Polish scientist pointed out that due to the curvature that characterizes the shape of the horse’s thoracolumbar spine, the vertebrae and muscles situated on the ascending side of the curvature were working in the opposite way than the vertebrae and muscles situated on the descending side of the thoracolumbar curvature.
In 1969, James Rooney demonstrated that the work of these muscle groups, which are arranged in mirror images, has to be perfectly synchronized to ensure proper locomotion. If the fascicles of the longissimus muscles contract first, the thoracic spine extends. If the fascicles of the spinaleus dorsi contract first, the lumbar spine stiffens. Rooney basically demonstrated the damage created by the shifts of the rider’s weight, which is a theory that is still emphasized in modern days. If the rider’s weight is acting back to front, as emphasized in the driving seat theory, the rider stiffens the horse’s thoracic vertebrae. By contrast, if the rider’s weight is acting front to back, the rider stiffens the horse’s lumbar vertebrae. Rooney’s findings suggested an equitation based on a rider’s body maintained constantly on a neutral balance, which is exactly vertical over the seat bones. One of the defenders of the long and low theory referred to “Pilates.” If this person really knew Joseph Pilates’ approach, she would have realized that maintaining the rider’s body in perfect neutral balance and therefore with the vertebral column almost straight is Pilates’ real teaching. Her perception of Pilates for the horse is that the abdominal muscles flex the thoracolumbar spine. This is not Pilates’ teaching. The real Pilates idea is to balance the work of both abdominal and back muscles to straighten the spine.
Rooney’s work also suggested that the real relation between the horse’s vertebral column and the rider’s back was more at the level of subtle movements of the rider’s back instead of shifts of the rider’s weight. In relation to the work of the back muscles, Rooney’s explanation differed from Tucker’s view. However, understanding how the horse’s vertebral column converts the thrust generated by the hind legs, which is basically a horizontal force, into forces resisting gravity, which are vertical forces, is easier to visualize mentally with Tucker’s explanation. This does not mean that Tucker’s explanation should be taken word for word. All these explanations are attempting to describe forces, which is an abstract concept. True understanding demands several ideas aiming toward the same concept. Rooney’s insight was that the creation of upward vertical forces through the spine was achieved by the direction of the muscles’ work without inducing much movement of the vertebrae.
The pathologist explained that in order to create horizontal forces, (forward movement,) and vertical forces, (resistance to gravity and balance control), two muscles are needed, one acting horizontally and one acting vertically, or, a single muscle acting in an oblique manner. Such insertion allows the same muscle to create both horizontal and vertical forces. This is exactly how the fascicles of the main back muscles are oriented and function. This was the beginning of a long series of research aiming toward a functioning of the horse’s back muscles based on the subtle management of forces instead of increasing the movements of the vertebrae. This was 1969 and we were, at that time, already far away from the infantile idea that a single action such as lowering the neck could flex the whole thoracolumbar spine and also that gaits and performances can be improved by increasing the range of motion of the horse’s thoracolumbar column.
Rooney also questioned the veracity of the bow and string concept. As a pathologist, Rooney observed firsthand the discrepancy between the large mass and power of the back muscles and small mass and limited power of the abdominal muscles. We have recently published a picture showing a cut-away of the back muscles and by comparison a cut-away of the abdominal muscles executed at the same vertical plain. Rooney basically demonstrated that abdominal muscles do not have the capacity to flex the back muscles. Longitudinal flexion of the horse’s thoracolumbar spine is instead, created by the precise coordination of the main back muscles that are situated above the vertebral bodies.
Rooney’s work suggested that the contraction of abdominal muscles would assist the flexion of the back but not create it. Instead of lowering the horse’s neck and stimulating hind legs engagement, as suggested in the video, the flexion of the horse’s thoracolumbar column is more likely to occur through harmonic motion of the rider’s back influencing the work of the horse’s back muscles. Three and half decades later, uneducated trainers and riders are promoting the lowering of the neck as a new way to engage the horse’s back.
Even if equine research studies were brought to a complete halt, the practical application of available knowledge would considerably enhance the horse’s performances and in particular the horse’s soundness. Very few of today’s advanced scientific discoveries benefit the horse through better training and riding techniques. The reason is that instead of questioning old ideas in the light of new findings trainers, riders and judges are integrating new discoveries to old beliefs. Considering the cost of raising, maintaining and training a horse, it is incomprehensible that the practical application of modern science, which could greatly prolong and further the horse’s career, preserve the horse’s soundness and consequently cut the vet bills, is rejected in favor of archaic but familiar approaches.
In 1976 was also when Hans Carlson demonstrated that the main function of the back muscles was CLICK LINK T READ ON http://scienceofmotion.com/equine_back_research.html
