Jean Luc Cornille
“The proper functioning of the locomotor system depends on precise synchronization of the movement of each part on every other part and in relation to the body as a whole. Pathological changes may occur whenever improper synchronization occurs.” (James R. Rooney) This is exactly why so many horses are lame. Training techniques as well as therapies concentrate on one part, eventually the proper synchronization of this part with a few other parts but never in relation to the body as a whole.
Let concentrate for instance on the fundamental element of all equine gaits and performances, the engagement of the hind legs. At the walk, as well as at the trot, greater engagement of the hind legs is supposed to make the hoof of the advancing hind leg reaching over the hoof print of the correspondent foreleg. The judging standard is irrelevant as in many instances, the hoof of the alighting hind leg impacts ahead of the foot print of the correspondent foreleg, not because of greater engagement of the hind legs but because of backward shift of the forelegs. The common adaptation of the forelegs to excessive load, is shifting of the whole stance phase of the forelegs backward. Instead of alighting ahead of the point of the shoulder and pushing off under or slightly behind the vertical of the stirrup, horses alight under the vertical of the point of the shoulder and push off far back under the belly.
The horse illustrating the backward shift of the forelegs as a response to heavy load, came at the center years ago. He was very heavy on the forehand as you can see on the left picture. The push off of the left foreleg occurred very far back under the belly.
Thirty minutes later, the same horse is less heavy on the forelegs and the stance of the forelegs starts to be placed more forward. The push off of the left forelegs occur under the vertical of the stirrups. The horse is still far from working properly; the neck is contracted, the thoracic spine is hollow, etc. The recording was made the day the horse arrived. I rode him as part of the initial analysis trying to figure the extent of the problem. He later became a nice mover. The purpose is illustrating the adaptation of the forelegs to heavy load.
Furthermore, focusing on one part, hoof placement, without understanding the relation between engagement of the hind legs and sound biomechanics of the thoracolumbar spine, exposes the horse to stifle injuries. Forward swing of the hind leg combines a pendular rotation of the femur around the hip joint coupled with a a dorso-ventral rotation of the pelvis. Mikael Holmström measured pelvis dorso-ventral rotation of good movers by comparison to mediocre movers and find a constant correlation between better gaits and greater dorso-ventral rotation of the pelvis. Rigidity or other dysfunction of the thoracolumbar column reduces or even hamper the dorso-ventral tilt of the pelvis. When asked to engage the hind legs without adequate function of the thoracolumbar spine and pelvis rotation, the horse increases the rotation of the femur around the hip joint extending the stifle beyond its safe range of motion. These are the conditions that create upward fixation of the patella. “If the extension is carried beyond about 143-145°, there is a final lateral-to-medial twist, which rotates the patella medially and hooks the patella-medial patellar ligament over the medial ridge of the femoral trochlea. The stifle is “looked” and flexion is prevented. In order to unlock, the quadriceps contracts (or the hip extend) lifting the patella. The biceps then contracts, pulling the patella laterally off the trochlear ridge and allowing stifle flexion.”
If the quadriceps and the biceps can contract fast enough, upward fixation of the patella can be prevented but quite often, sharing forces occur which, repeated stride after stride, damage the stifle. We often denounce the irresponsibility of training techniques acting on the legs without adequate vertebral column mechanism. When knowledge of equine biomechanics was in its infancy, it was common belief that deeper engagement of the hind legs was always good. With today knowledge, a different picture takes form. Greater engagement of the supporting hind leg remains a sound objective but at the condition that more advanced hoof placement results from proper synchronization of the movement of other joints, fetlock, hock, stifle, hip, and in relation to adequate functioning of the thoracolumbar spine. When artificially created by acting on the limbs instead of educating the thoracolumbar column, greater engagement of the hind legs is a dysfunction inducing aberrant stresses on the hocks and stifle joints. At the science of motion, we resolve stifle problems recreating proper functioning of the thoracolumbar spine. Basically, we restore soundness creating the coordination of the whole body which, would have prevented stifle injury if the focus has been on synchronizing precisely the horse’s physique for the athletic demand of the performance instead of asking the horse to perform the move or simply the gait with a dysfunctional physique.
James Rooney studied the kinematics abnormality causing pathological changes and therefore injury. The veterinary world did not follow Rooney’s discoveries because diagnostic tools, drugs and static therapies could not address and correct the kinematics abnormality. This aspect belongs to the riding and training techniques as kinematics is the geometry of movement and dynamics is the interaction of forces. Both can only be addressed and eventually corrected through locomotion and appropriated gymnastic. Our initial application of James Rooney research was for performances, winning in the show ring and winning again which implies that the horse remains sound. Since absolute synchronization, perfection, is never achieved, the horses’ propensity of remaining sound was greatly improved but injuries occasionally occurred. They were addressed and corrected furthering the analysis of the horse’s body coordination and furthering the precise synchronization of the horse’s physique. This is where the ability to identified the root cause of the kinematics abnormality causing injury was developed.
The practical application to therapy is indeed, what proper training should be. When Domnique was diagnosed with severe navicular syndrome, the ultimate performance for him was not executing tempi changes in the show ring, but instead regaining soundness. The source of the right front limb kinematics abnormality inducing excessive stress between the distal sesamoid and the deep digital flexor tendon was a deviation of the thoracic vertebrae bend to the left with an inverted rotation shifting the dorsal spines to the right. By correcting the deviation and torsion of the thoracic spine, we recreated proper kinematics of the right foreleg and abnormal stress disappeared. The horse regained soundness and was then capable to perform tempi changes that he was not capable to perform prior his navicular issue. If proper functioning of the thoracolumbar spine has been created on the first place, the horse would have been capable to perform tempi-changes and would never have developed navicular syndrome.
“The significant problems we face today cannot be solved at the same level of thinking we were at when we created them.” (Albert Einstein) The principles of riding and training that created the problem cannot be used to resolve the problem. This is the paradigm shift that responsible riders and trainers, as well as horse owners have to face. Soundness will not be recreated treating one part, manipulating peripheral parts but then returning to the riding and training techniques that do not understand interactions between limbs kinematics and vertebral column mechanism. Instead, soundness, greatness and the fascinating evolution of the horses’ intelligence can be achieved updating the wisdom of our ancestors to actual knowledge. Refining the accuracy and soundness of one body part through its precise synchronization with every other part and in relation to the body as a whole is the class preached by great authors. Classic authors did not preached conservatism; they promoted evolution. “The cult for the tradition does not exclude the love of progress ." (Colonel Danloux)