Picture show the maximum stress on the deep flexor tendon (dotted) prior to break over (delayed) when riding on a hard surface.
Picture shows the reduction of the stress on the deep flexor tendon (dotted) by reducing the break-over stress point when riding on a deeper surface.
A toe-grab (toe-grip) of a racing shoe to prevent premature break-over on a deeper running surface.
The inbred high action of the Kladruber stallions (the ultimate carriage horses) easing the break-over stress, thus enabling longevity while working on hard surfaces.
A break-over point deviates from the center in the direction the horses is moving.
The white field shows common break-over "point" area in most riding horses. The black fields show the extreme break-over point deviation like in cutting or barrel-racing horses.
The orange line shows the change in
break-over by either squaring or "rocking" the toe. This will
destabilize the break-over momentum when traveling to the
| The concept of break-over is again one of the most misunderstood factors
in movement of the horse. Most people completely forgot or are not aware
of the main facts that come in question.
In case you didn’t know, what the “break-over” term refers to, it is the moment at which the carrying function of the forelimb ends when the horse’s “knee” bends (buckles) at which point the opposite leg must come down since the forelimbs are so-called fixed. To understand better the term “fixed”, one can imagine standing while resting one leg, as it is common when we stand for a while. If someone will come from behind and pushes unexpectedly on the supportive leg (fixed) the person’s leg will buckle at the knee. Since our legs are not fixed the same way as the hind legs by the horse are not fixed, the person is able to recover by pushing with his legs up. The horses are not able to do that in the front legs and the premature or surprising break-over or buckling under can result in falling down. The horses have very little control over the mechanics of the front legs, thus when the break-over is altered it will greatly influence their movement. It is therefore very important that we understand all the factors that are involved in the break-over function.
The break-over momentum (timing) is greatly influenced by the hoof and it’s angling and positioning. However, this is just about all that most people know and perceive, while forgetting many other elements that influence this fraction of a moment. One of the most ignored factors is the working surface, its texture and depth. Horses traveling on a deeper surface will break over easier and quicker, hence when riding in very deep terrain, the horses action is higher (“climbing”) and the stride is shorter. When going on a hard surface, the break-over is delayed to the maximum, thus the stride lengthens, the action is somewhat lower (flatter) and the break-over stress increases.
The second and completely ignored factor by most farriers, riders, trainers as well as the veterinarians is the lateral alternation of the break-over stress point in relevance to the hoof. In other words, when most people think about break-over, they are thinking about the point of the break-over being at the center (front) of the toe. This is true only when the horse is traveling in a straight line. As soon as the horse turns (riding on a circle) the body of the horse tilts as well as the carrying positioning of the legs and the break-over point moves to the side to which the horse travels. Since it is here, during the lateral stress when the legs suffer the most, attention must be paid not only to the surface but also to the shape of the toes. Here is where I get frustrated so much, with all this “bull ….” about rolled toes or squared toes in horses that are ridden in limited spaces.
Other factors that are involved in break-over momentum are the gaits and speeds. Therefore, the racehorses (low action - long stride - gallop) are shod much differently than for example the carriage horses (high action - shorter stride - trot). I will use these two types of horses to show the contrast that the break-over plays on the performance and the durability of these horses.
The racehorse needs to travel on a deeper (sand-clay), supple (grass) surface to reduce the impact on the "over-extended" front leg, thus prolonging the working life of the racehorse. (One has to imagine the immense landing - carrying impact in the racing horse, when the entire body of the horse is literally thrown forward about 26 feet in one stride not to mention the speed of it.) To prevent the premature break-over (shorter stride) that can be caused by traveling in a deeper surface (sand-clay), the so-called toe-grab is used. This type of a shoe in front will insure longer stride while it will give more “pushing” traction to the hind legs. On the grass there is no longer need for the toe-grab, since the grass is the ideal and more natural surface (not too deep but supple) for the running thoroughbred. The inbred angling of the hoof is also much lower, usually below 50 degrees in front legs. The lower the angle, the more the break-over is delayed and the stride is longer. As a carriage horse, this horse would be lame within days. (The old-timers-trainers were bitching at the riders every time, whenever they trotted the racehorses too fast.)
The older type of carriage horse had to travel all day on hard surfaces; henceforth, the break-over is eased by the inbred higher angle (50° and up) of the hoof, thus providing higher action and shorter stride. In this way, the impact factor is reduced, since the body is not “thrown” far forward as in the racing horse. These horses were also bred for that purpose; hence they were also anatomically suited for such work. I assure you folks, these horses traveled every day and years on stone-paved streets and they stayed sound without anyone doing any break-over adjustments as in rolled or rocker toes. As a racehorse this horse would not last, not to mention his lack of speed in gallop.
The relevance of action to the break-over is of great importance and when ignored it will lead inevitably to soundness and/or performance problems (Western Pleasure horses etc). Henceforth, if we use squared toes, rolled or rocker, we are putting these two elements out of harmony (shortening stride without increasing the action). The negative effects of “playing” with break over in such way will be discussed in a separate article. (The rolled – rocker toe is exclusively part of therapeutic shoeing, separate issue)
One other important anatomical fact that has a great influence on the break-over momentum is the function of the pastern. This will be discussed separately, because of its importance, especially when choosing suitable horses for certain work.
The direction of the impulsion line and the impulse-power of the hind legs in the performance horse also has a great influence on the break-over stress point. Horses traveling with a sufficient impulse-power and with the impulsion line upward are driving their bodies not only forward but they are lifting the forehand, thus easing the break-over stress on the forelimb. Because of his higher action, his impulsion line upward with sufficient impulse power of the hind legs, the Standardbred can trot (not gallop) fast on hard surfaces [before the break-over the front leg is partially lifted into the air by the hind leg (hip - back - shoulder - neck - head)], providing the hind legs are sound and can do so.
People today are failing to understand not only the factors in the break-over momentum, but they completely forgot to evaluate the suitability of an individual horse for a particular work. Because of it, people look for answers in the wrong places (changing break-over), which results in immense horse-abuse, especially by the so-called “professionals” who are at the “spot light”. The horsemen and judges that are at the "top" are responsible for the decadence in the horsemanship world wide, because the average (amateur) horse person looks up to them, while at the shows we need to do what the incompetent judges like, rather than what is appropriate.
In conclusion, do not look for the solution of problems with your horse in the farrier, but re-examine first what you are doing to your horse as a trainer and/or rider. I believe that much lameness in horses is caused by the trainers/riders and not by the farriers. Unfortunately, we tend to throw our problems on the farriers, who then try to correct something they didn’t cause in the first place, thus adding to the problem.
line is upward thus pushing the horse's body not only forward but up
|henceforth easing the stress on the deep
flexor tendon at the break-over stress point.
|A riding disaster of today's dressage. Too hard surface while the horse is extremely off balance. Add the lateral stress and now you know why such horses go lame. Trot with three legs off the ground? What's that?|
More photos coming soon.
|Flying through the air about 26 feet stride, the landing impact is immense. The soft and supple surface is essential.||Contrasting the picture above (dressage). Impulsion line well up. Pushing very strongly of his hind legs, unlike the dressage horse above.|
All my comments are merely my opinions and beliefs gained from 40 years of professional life with horses. All drugs should be used only by the consent of a veterinarian and according to his instructions. A person who is with the horse everyday, should know him better than anyone else.