With all the talk in "natural horsemanship" circles about learning the horse's language, this aim can never be achieved when it begins and ends with a questionable premise, that a horse enjoys being ridden.  In my studies, I have come to the conclusion that horses have learned our language far better and more honestly than we can imagine. This is why all the "new agey" books and teachers are talking about how horses are our mirrors. I'm not talking about horses understanding our spoken language to any great extent, but they are masters at understanding the language that we seem to have forgotten, the language of our actions.  

As a veteran horse trainer, one of the things that most surprised me to learn was the science of what goes on in a horse's back when it is subjected to a saddle and rider. Sure, I knew that horses occasionally got sore backs and needed treatment or a better fitting saddle but I certainly didn't understand what goes on each and every time a horse takes someone for a ride.

One of the reasons that some of this information might seem to be "new" is that it wasn't until around 1992 that the "Saddletech" saddle pressure testing pad was developed. These pads, and other similar devices more recently developed, include sensitive sensors that can measure the amount of pressure between horse and saddle. These pressure-sensing technologies lead to a flurry of interesting scientific studies in the equine world.  When this information was combined with other studies of mammalian muscle tissue it all suddenly pointed to a huge dilemma. In the Journal of Veterinary Science Volume 14 No. 11, 1994, well known veterinarian and saddle fit expert Dr. Joyce Harman reported the results of a study using the Saddletech pad. She wrote:

"For the purposes of this study, saddles with pressures of up to 1.93 psi were graded an excellent fit, between 2.0 and 3.38 psi without persistent pressure points were graded fair and saddles that exceeded 3.4 psi or had persistent pressure points throughout the session were graded poor. These numbers were derived from preliminary data indicating that it was difficult to find an English saddle with pressures below 0.75 psi, which is the highest pressure found in the capillary bed. Pressures that exceed 0.75 psi will close down the blood flow in the arterial capillary bed."

So what does it mean if the blood flow is shut down? This is what happens on a small scale when we press on our skin and it turns white, or if we sit in an awkward position for a longer amount of time and we experience our leg or arm "going to sleep". The author, Mary Wanless, writes in her book "For the Good of the Horse", "Perhaps one of the horse's saving graces is that squeezing the blood out of his tissues causes pain for the first ten to fifteen minutes of a ride, and then his back goes numb."

So, until we learn how to levitate saddles, even a saddle with an excellent fit, the best air/foam/wool stuffed panels and an average weight rider, will have pressures which are more than twice what it takes to shut down the blood flow within the muscles. Dr. Harman goes on to state that in studies of canine and human muscles, sustained pressure of only 0.68 psi for over two hours causes significant tissue damage.

It is important to note that the Saddletech sensor pad used in these first studies used sensors developed to evaluate the risks of pressure sores in bedridden humans, and only measured pressures of up to 4 psi. More modern sensor pads, such as the FSA (Force Sensing Array) system developed by Vision Engineering Research Group (VERG Inc.) of Winnipeg, Manitoba, Canada can record much higher pressures.  In one test involving Western saddles with high priced pads, average peak pressures measured between 8.25 and 14 psi. (Wesley, E.D.; McCullough, E.; Eckels, S.; Davis, E.; Article #9329; 2007; "The Horse" magazine).

Pressure sensing pads also have the limitation of only recording pressures at the level of the skin.  Saddle pressure is transferred through the muscles to the bony structures underneath (the vertebrae and ribs) and if we could measure the pressure there, it would be significantly greater. Dr. Harman writes that, "There is surgical evidence in human medicine that subcutaneous necrosis [the death of cells] begins closer to the bone before cutaneous redness and ulceration is seen." This means that if we've been around horses long enough to notice white spots or tender swellings in the saddle area, we are only witnessing the end results of a long process of tissue destruction. The longissimus dorsi and trapezius muscles that a rider sits on have been developing since the dawn of the horse, when Eohippus first used them to facilitate movement. Their structure was never created to bear weight in the form of vertical pressure from above, and this remains true even after centuries of selective breeding for "riding" horses.