There must be a better way to fit a saddle by Robert Ferrand

THERE MUST BE A BETTER WAY TO FIT A SADDLE TO A HORSE ! A WHITE PAPER By

Robert Ferrand Inventor / CEO

May 1, 2004

2995 Woodside Rd. Suite 400, Woodside, CA 94062 Phone 650 - 631- 8400 E-mail – inventor@saddletech.com WWW.SADDLETECH.COM

THERE MUST BE A BETTER WAY TO FIT A SADDLE ! Back in high school geometry class, we all learned that it required a minimum of three points to determine an “Arc”. However, today, equestrians are told by saddle fitting experts that you can determine the “Fit” of a saddle to a horse’s back by using the cross-section at the withers, back, and loin. Three separate two-dimensional shapes, independent of each other cannot physically determine an arc, there is no way around it. The fact is: to determine if a saddle “Fits”, “Rocks”, or “Bridges”, the laws of geometry require the comparison of all three (3) dimensions, in relationship to each other. It is geometrically impossible to determine the curvature of the horses’ back relative to the saddle, if the individual cross-sections are not locked into a relationship to each other.

In 2004, saddles are not even measured for any “Arc”. We only have Gullet Width, with terms such as Narrow, Medium, Wide, Quarter horse, Semi-Quarter horse, and Arab. Unfortunately, these terms cannot describe a three-dimensional surface, so it is impossible for anyone to relate the shape of the saddle to the shape of the horse’s back. This situation, at a minimum reduces the animal’s performance and in the worst case can cause serious injury, and cost the consumers a lot of money. However, over one hundred years ago saddles were measured in three dimensions. In 1875, the United States Cavalry measured McClellan saddles very precisely as is illustrated in this drawing, below.

It is geometrically impossible to build an accurate three-dimensional template without precise x, y & z axis coordinates. You can see that the two-dimensional views in this Cavalry saddle specification drawing, on the right, are measured in x, y & z axis coordinates. By calibrating the structure in this manner, templates such as the one displayed above, were used by the Cavalry to establish quality control. However, that said, in 1897, the U. S. Cavalry reported “It was found that as high as 45 percent of the trees on hand furnished by some contractors during the (Civil) war had to be rejected”. Unfortunately, today, western saddle trees are currently still made by employing basically the same century old antiquated techniques, however, without the assistance of three-dimensional coordinates and detailed specification drawings. TODAY, THERE IS A COMMON MYTH THAT WIRE TRACINGS CAN BE USED TO FIT A SADDLE

MALE TO MALE WIRE TRACING

3 - 2-D TEMPLATES

The prevalent technique of using baling wire or flexible curves to determine the fit of the saddle creates a significant error, because the three points required to determine an ARC are not defined. You can use the flexible curve to determine the TWO-DIMENSIONAL shape of the contour of the horse’s back in a number of positions down the back and those shapes can be transferred to a piece of cardboard. However…….

TO MAKE AN ACCURATE 3-D TEMPLATE REQUIRES: MEASUREMENT THE REALITY IS: IT REQUIRES A FEMALE TO MALE TEMPLATE TO HAVE ANY 3-D ACCURACY

FEMALE TO MALE

FEMALE

MALE

Now, building a three-dimensional template that does lock the individual two-dimensional crosssections together so that the three-dimensional shape of the horse’s back can be duplicated requires significant skill. The techniques to build such three-dimensional shapes have been well established in the boat building trades, for centuries. This technique is called “Lofting” and it requires precise measurements of the x, y and z axis coordinates for each of the individual parts. Boat builders do use flexible curves to connect the dots, but the dots are precisely measured to establish reference points relative to each other, and that is how the accuracy is achieved. This “lofting” technique was illustrated previously in the McClellan saddle specification drawing above.

The challenge is to determine the reference point on the horse, which can then be transferred to the three-dimensional template. While “level” may appear to be a reference point, it requires very careful placement of the cross-sections in relationship to the level or perpendicular positions and at the same time - relative to each other. Even if we assume that all this is done accurately, unfortunately, the shape is incorrect because the effect of gravity caused by the weight of the rider is not considered. This is why a “female” template is required to place on the horse, to be sure that no errors were introduced. Once the accuracy of the female template is established, the male template can be built by using the female template for reference and adjust for the effect of the rider’s weight. Without a method to “double check” the accuracy of the three-dimensional shape, all credibility in this method is lost because there is no reference point or feed-back loop. WHY HAVE WE NEVER SEEN PHOTOS OF 3-D TEMPLATES IN SADDLES, IF SADDLEMAKERS ARE MAKING THEM? Because it also requires significant time to cut out the 2 sets of 10 individual parts: cross-sections, longitudinal stringers and cross members that create the 2 rigid three-dimensional templates. Since each of these sections must be interlocking, there must be “egg crate” type slits in each of the parts. If any of the cross-sections, stringers or slits are not accurately cut in relationship to each other, the accuracy of the total structure is compromised.

THIS IS “NOT” A BETTER WAY TO FIT A SADDLE! To actually build such a three-dimensional template of the horse’s back requires a 4 foot by 8 foot sheet of card board, that is cut down to approximately 12 (14 inch by 24 inch) sections. This is where “Lofting” is most useful, because by defining the x, y and z coordinates of the 3-D structure, the parts can be measured and accurately cut. You cannot just transfer wire shapes on to the layout, willy-nilly, because the parts need reference points to determine their interrelationship to each other or the accuracy of the shape is compromised and becomes absolutely meaningless. To achieve any reasonable sense of accuracy does take time, as outlined below: Process to make 3-D Template Measure the Horse Transfer Wire Tracing to paper Loft Tracing X, Y, Z Coordinates Draw Accurate Grid for reference Transfer Coordinates to 10 Female Parts Cut 10 Female Parts Assemble Female Template Check Female Template on Horse

160.0 20 20 20 20 20 20 20 20

Min

Min Make Ajustments Transfer Coordinates to 10 Female Parts Cut 10 Male Parts Assemble Male Template Check Male Template in Female Make Ajustments Test Saddle

140 20 20 20 20 20 20 20

Total Time to Make 3-D Templates 5.0 Hrs

Even assuming that the saddle maker or saddle fitter is a highly skilled craftsman, and only does the minimum of three cross-sections to define an ARC and can perform each step in two minutes, with no mistakes or corrections, it would take a MINIMUM of 5 hours to make a three-dimensional template of the horse’s back, that would have any reasonable accuracy. For greater accuracy, five cross-sections should be made, then, at best, only one template could be built per day. At this point, the saddle maker becomes a pattern maker and would be out of the saddle business. THE TRUTH IS NO ONE REALLY MAKES THESE 3-D TEMPLATES. WHICH IS WHY NO PHOTOGRAPHS OF SADDLE TEMPLATES CAN BE FOUND ON THE INTERNET.

SO WHY ARE BALING WIRE AND LINE TRACINGS USED TO SEND TO THE SADDLEMAKERS ? WHY DO CUSTOM SADDLE MAKERS NOT PROVIDE THESE 3-D TEMPLATES WITH THEIR CUSTOM SADDLES ?

BECAUSE NO COMPANY CAN AFFORD THE TIME IS TAKES TO MAKE THE TEMPLATE ACCURATELY. SO WHY DO WE RISK INJURING OUR HORSES AND LOSE MONEY, WITH THIS ILLUSION ? All the expert saddle fitters agree on the importance of saddle fit. HOWEVER, IF WE DO NOT HAVE ANY ACCURATE MEASUREMENTS, HOW CAN WE POSSIBLY KNOW WHETHER A SADDLE DOES FIT?

There are some who believe that a plaster cast or thermoplastic sheet draped over the horse’s back is the solution to determining saddle fit. This creates a “mirror image” of the shape of the “Unmounted” horse’s back. However, this shape does not have any numerical values, so it cannot be calibrated, it cannot be entered into a database, it cannot be mathematically referenced to other three-dimensional shapes. Baling wire, Plaster cast or plastic sheets, do not employ numerical values, so they have limited utility in calibrated saddle manufacture or saddle fitting because there is no reference point or feed-back loop. Nonetheless, a number of so called “experts” have jumped to the conclusion that this shape must be the shape of the saddle that fits the horse’s back. However, has anyone ever provided any objective evidence that this is true? More importantly, has someone actually measured this concept and discovered that this approach is actually mathematically incorrect?

MEASUREMENT IS THE BETTER WAY TO FIT A SADDLE What if the gravitational forces, are strong enough to cause the back of the horse to bend just enough to cause the saddle that visually “APPEARS TO FIT”, to actually “BRIDGE”, due to the rider’s weight? Maybe the saddle fitting problem is: that it takes so much time to actually build the threedimensional templates of the horse’s backs, that no one actually built those templates, so no one caught the error. Since we have never had any saddle measurement instruments accurate enough to detect this error, no one figured it out. Without the assistance of mathematics, people jumped to conclusions and did not have a “feed back loop” to correct for the error. If this is true, then maybe we need to change the way we think about saddle fit. So how can we determine the facts. TO SOLVE A PROBLEM, FIRST DEFINE IT PROPERLY. Throughout history complex problems have been simplified by using measurement. Today, we can send a “ROVER” to Mars over vast distances and time by using measurement. However, when it comes to saddling horses, there is a prevalent mythology that fitting the complex polyform shape of the horse’s back (a hyperbolic parabola) to the complex polyform shape of the saddle (a hyperbolic parabola) can be accomplished WITHOUT measurement. While some consider a piece of baling wire or plaster cast or plastic sheet to be a form of measurement, the truth is: measurement requires a "UNIT OF MEASURE". Three-dimensional polyforms do not have a unit of measure. More importantly, complex measurement requires some form of “calibration”, that relates the "UNIT OF MEASURE" to a “KNOWN STANDARD”. Accurate measurement requires a “feedback loop”. A feedback loop corrects for the errors or “hysterisis” in the measurement technology itself – and thereby accuracy is increased by relating the measurement to a known reference point. NO STANDARD - NO ACCURATE MEASUREMENT. Now, if we assume that the shape of the horse’s back can change, to be able to know “how much” the back of the horse bends under the weight of the rider requires two sets of three-dimensional coordinates. The first is the shape of the horse’s back without the saddle and rider, and the second shape is with the weight of the saddle and rider. However, how do you measure the three-dimensional shape of the horse’s back with the saddle and rider in the way of the measurement, itself? Obviously, we need to “triangulate” on the problem. Triangulation is a method of measurement from two different reference points. If it were theoretically possible to measure the three-dimensional shape of the horse’s back with numerical values, without the weight of the rider, and then compare that shape to the corresponding measurement of the saddle - the relationship between those two shapes could be reduced to a formula. Now taking this one step further, if it were theoretically possible to measure the actual interface pressure that is exerted by the saddle of a measured shape with the rider on the back of the horse, the shape of the saddle that “does fit” and the saddles that “do not fit” could be determined. To validate this calculation, if it were theoretically possible to create a number of different saddle shapes that would each be just a measured amount different, one to the next, and then if we could measure the interface pressure exerted by all of these different shapes on the same horse’s back the formula could be “calibrated” and this calculation validated. All of these measurement devices and the “measured” saddle shapes are not only theoretically possible, these calculations have already been done years ago, and all this technology is available for you today on the Internet at www.saddletech.com

SO….HOW CAN YOU CALCULATE HOW MUCH CORRECTION IS REQUIRED? How can we possibly find a more reasonable way to fit the saddle to the horse, so we can figure out what the effect of the weight of the rider has on the shape of the horse’s back, so we could choose a saddle that fits? Well, the answer is: if we could make a calibrated clear plastic structure that we could actually see through, that could simulate the shape of the saddle, so that we could actually see how that shape relates to the shape of the horse’s back, we could test the theory if the “mirror image” does fit the horse when the rider is mounted. If we place this calibrated plastic structure on the horse that we can obviously see for ourselves that does “APPEAR TO FIT” the mirror image of the horse, as we have been told to do, and then if we place that structure on the pressure sensitive pad on the horse, we should be able to see if it “FITS” when the rider mounts. If it does not fit and it “bridges” we can see that the saddle fitting problem is that the “saddle fitting experts’ have been overlooking the obvious that gravity is one factor, and it is high time to change our strategy.

You see the structure on the left “APPEARS TO FIT”, but the pressure map reveals that it actually “Bridges”. However, you can see the image on the right, that the structure APPEARS to “Rock” slightly on the horse’s back, however, if you look at the adjacent computer scan, on the right, with the rider in the saddle you can see that the pressure is relatively even. Bingo, we are on to something here. So there you have it, “EVIDENCED BASED” objective proof that using the three-dimensional back shape of the “MIRROR IMAGE” CANNOT POSSIBLY FIT a saddle to a horse, because gravity is one factor. To further prove the point, the example below is a set of nine saddle shapes each precisely made on a calibrated jig, so that the relationship of the shapes can be calibrated to the shape of the horse’s back. By employing this method each shape can be made incrementally 10 degrees different, narrower, wider, flatter or more rock. These shapes can then be tested on the same horse using a computer interface pressure measurement device, and you can see pressure distribution From the results, you can readily see that the shape of the structure in the center has uniform blue color, signifying that the pressure is relatively even and about one pound per square inch, which can be defined as “FIT”. This experiment confirms that flatter saddle shapes, which “APPEAR TO FIT” do cause uneven pressure, because gravitational forces are significant. Adjusting the saddle to the unladen horse’s back causes an error, because the weight of the rider and saddle is not considered.

So how can we figure all this out ? - With calibrated measurement ! CHALLENGE # 1 : MEASURING PRESSURES UNDER THE SADDLE

The Saddletech Pressure Mapping System consists of a pressure sensitive pad attached to a computer. The pad contains an array of pressure sensors that measures 24 inches by 32 inches. To use this pressure sensitive pad, the sensor pad is placed between the horse and the saddle/pad combination and is connected to the computer. When the rider mounts the horse, the system graphically displays a variable color map that shows the amount of pressure and the location of the pressure exerted by the saddle and rider on the horse’s back.

CHALLENGE # 2 : MEASURE THE SHAPE OF THE HORSE’S BACK & SADDLE ANGLE 0

ARC 0

ANGLE 0

[ 20 ] 110

ARC 0

[ 10 ]

A NGLE 0

120

ARC 0

ANGLE 0

[ 5 ] 130

The SADDLETECH GAUGE Mk I I is a simple mechanical three-dimensional calculator that permits the polyform shape of horse's back and corresponding saddle to be described by a few angles and arcs. You can see the example on the left of the horse’s back, shows a number of pencils that describe the saddle contact area. By determining the interrelationships of these flat lines to each other, you have a set of numbers that permit a measured calculation. The SADDLETECH GAUGE is useful because it can be used in conjunction with the SADDLETECH FORMULA to determine how much the weight of the rider changes the shape of the horse’s back. In a matter of minutes, the SADDLETECH GAUGE MK I I automatically creates the x, y & z-axis three-dimensional reference points, that would normally take hours to duplicate, saving time and money. With the GAUGE properly adjusted, the GAUGE can be placed in the saddle to determine the best possible fit. The GAUGE can also be used as a 3-D template to allow the saddle to be adjusted accordingly. Or the SADDLETECH GAUGE MEASUREMENTS can be used to search on a measured saddle database to match the horse to the saddle with the best possible fit. These same measurements can also be used to order a “Custom” Saddle, Saddle Tree, or a SADDLETECH ORTHOTIC. In practice, it is rather simple. Once you have the SADDLETECH GAUGE measurements, you just look on the chart for the weight of the rider and follow the line corresponding to the horse’s weight. By adjusting the SADDLETECH GAUGE wither and loin “ARC” by that amount, the appropriate amount of “Rock” in the saddle can be determined. The SCAPULA CONTOUR DEVICE, provides for the measurement of the scapula or “saddle pocket” for additional accuracy.

CHALLENGE # 3 : CALCULATING THE EFFECT OF RIDER WEIGHT Ferrand’s Formula Weight Compensation Factor

Rider Weight

Established Rider Weight

Established Horse Weight

RW - C

WCF =

----------------B

Patents Pending

Incremental Weight

Horse Weight

Z - HW

--------------Y Incremental Weight

The SADDLETECH FORMULA is a simple way to determine how much “Rock” there needs to be in the saddle to account for how much the rider’s weight causes the horse’s back to bend, ever so little, but ENOUGH TO MAKE THE SADDLE THAT VISUALLY APPEARS TO "FIT" WITHOUT THE RIDER, TO ACTUALLY "BRIDGE" UNDER THE ADDITIONAL RIDER WEIGHT.

The concept is simple. If you put 10 pounds on the horse’s back, the back will not bend. However, if you keep putting 10 pound weights on, one right after the other, at some point you will reach the proverbial, “straw that broke the Camel’s back”. From then on, each increment of weight can be measured as one degree on a three-dimensional measurement device. The SADDLETEH FORMULA is a simple mathematical calculation that creates a relationship between the weight of the rider relative to the weight of the horse, BY CALIBRATING THIS MEASUREMENT TO THE ACTUAL INTERFACE PRESSURE. To explain the graph above, the Weight Compensation Factor (WCF) equation is WCF = (RW - C) / B + (Z - AW) / Y, where WCF is the change in the relative angle of each pair of wings, RW is the weight of the rider, ( C ) is the established weight of the rider, B is the variance in weight of the rider from the established weight of the rider corresponding to an angle of adjustment of one degree, ( AW ) is the weight of the animal, ( Z ) is the established weight of the animal, and ( Y ) is the variance in weight of an animal from the established weight of the animal corresponding to an angle of adjustment of one degree.(U.S. Patent #6,334,262)

CHALLENGE # 4 : HOW TO VALIDATE THIS CALCULATION

Horse Measurement

100

130

140

Horse Lbs 1100 WCF

140 5

Rider Lbs. 3.67

220

Weight Compensated Measurement 100 130 140 140 29 10 9 Saddle Measurement

100

130

140

Saddle Variance 0 Angle 0 0 Arc

Percentage Accuracy Overall Angle 100 % 100 %

140 9

0 0

Arc 99

CHALLENGE # 5: AN EVIDENCE BASED METHOD TO FIT A SADDLE

EVIDENCE BASED SADDLE FIT is the use of scientific research as the basis for understanding saddle fitting and coupling this research with measurement data. By employing three factors a “feedback loop” can be created to validate measurement criteria and determine a superior saddle fit. By first establishing three-dimensional measurement coordinates to describe the polyform shape of the horse’s back, then employing a mathematical formula to correct for the effect of the rider’s weight relative to the horse’s weight a more accurate understanding of the shape of saddle that will provide a superior fit is possible. By then taking the additional step of measuring the actual interface pressure that is exerted by the saddle and rider on to the horse’s back a validation and or calibration of this measurement is also possible, thereby creating a “feedback loop.” Rather than traditional saddle fitting methods which are completely based on assumptions, without scientific basis or supporting measurement data, in contrast, Evidence Based Saddle Fitting is totally based on physics, physiology, mathematics, and calibrated measurement. Equally important, is the employment of numerical values permit saddles to be accurately manufactured. In all the discussion about saddle fitting, it is often forgotten that some saddle maker, soon or later, must build or adjust the saddle. But what is the shape? Tack shops or individual equestrians have to know the shape of the saddle to be able to order with any chance of the fit. But how can you describe the three-dimensional shape? By employing numbers, many opportunities are provided: 1. Horse measurements can be entered into measured saddle databases to find a saddle that FITS 2. Calibrated adjustable jigs can be made to improve the saddle manufacturing process, 3. Computer controlled routers can be programmed to build saddle trees to a calibrated shape, 4. Calibrated Saddle Orthotics can be custom made to adjust for poorly fitting saddles 5. The saddle can be readjusted to refit the horse as its back changes over time. The “Great Saddle Hunt” can end by using calibrated measurement. Once again measurement is your friend. Fortunately, saddle fitting is not rocket science, but it does require some sort of valid measurement technique to be accomplished with any resemblance of accuracy.

…BUT HOW DO I ACTUALLY FIND A SADDLE THAT FITS MY HORSE ?

BY USING A UNIVERSAL STANDARD NUMERICAL LANGUAGE An equestrian, a tack shop, a saddle distributor, a saddle maker, & a saddle tree maker Can all accurately describe the three-dimensional shape of the horse and saddle So that a relationship called “saddle fit” can be determined

ACCURACY MATTERS WHEN HUMANELY FITTING A SADDLE TO A HORSE! 10