Reprinted from The Icelandic Horse Quarterly: Issue Three 2010.
The Icelandic Horse Quarterly is the official publication of the US Icelandic Horse Congress. The magazine is printed four times annually and mailed to the membership. Back issues may be purchased for a small fee and may be read online at

Do you know that look some people get when you’re sitting around with a couple of other horse nuts yakking and yakking about all things equine? The sane people often get a glazed look in their eyes. Some tend to nod off or get up and go in search of conversation not so equine-centric. I feel like that when I get going on and on about saddles. Sadly, it’s usually just me in the “conversation.”

Yet even I found a lull in the brainstorm this hot summer. When I whined to the Quarterly Committee that I had no inspiration as to what to write about for this issue, fellow committee member Bernie Willis sent an email. Part of it reads:

“I have a couple of concerns about saddle fit that so far I find unaddressed. First is the fact that the back of a horse changes with movement. The back comes up when the neck stretches forward and down. The back goes down when a horse is pulled up with the reins. The large back muscles ripple on opposite sides when the horse trots. This is fascinating to see when ponying. It seems that a perfect static fit is only perfect for standing still. Even in walk, the alternating hip movement is felt in the rider’s seat. Does this mean that a rigid tree interferes with the walk? I’d like some answers to these situations.”

Yum. Perfect opportunity to do the saddle-geek thing and go on and on to at least an audience of one.


To begin with, a saddle tree is rigid, but not inflexible. A well-made wood laminate or poly carbonate tree has some amount of flex to it that is enhanced with the use of “springs.” Thus you’ll often see “spring tree” stamped on the flap or used in advertising. Those springs are straps of various materials (often steel) strung from the cantle to the pommel with enough tension to create a bit of a dip in the seat as well as from the front to the back of the tree.

The rider’s weight down or up activates the springs and flexes the tree. It is not as flexible as a treeless pad, but that’s on purpose. Flexible trees, by their very nature, deeply flex and cannot evenly divide weight. Anything that flexes cannot distribute weight consistently, equally, and evenly. Treeless saddles can work for some lightweight people. The limitation is that treeless saddles do not have a foundation. All of the rider’s weight is focused on the seat bones, and there is little relief for your horse in that area. In order for a saddle to effectively distribute the rider’s weight over the most available area on the horse’s back, some amount of rigidity is needed.

Pressure, in physics, is force per unit area; that is, force divided by the area against which it is applied. A common unit of measurement for pressure is the pound-force per square inch (often called simply pound per square inch and abbreviated psi). Since pressure depends on both the area and the strength of a force, a given force can produce widely differing pressures. For example, a 10-pound force applied to an area of 1 square inch exerts a pressure of 10 psi. The same force applied to an area of 10 square inches exerts a pres- sure of 1 psi. You can see why it is desirable to have the largest surface area possible to avoid pressure points transferred from rider to horse. The tree acts to distribute the rider’s weight over and through the panels, which should be as large as possible and fitted correctly to the angles of the horse’s back.


The horse is dynamic. The rider is dynamic. The saddle is practically static. It has, as explained above, some flex, but to a lesser degree than either horse or rider. Rounding the horse’s back means the horse has lifted his back, is using his hindquarters well underneath, and is moving in a circular energy, as opposed to horses with inverted or hollow backs and trailing hind legs. The ligament that runs from the top of a horse’s neck down the spine into its tail is the spinal nuchal/supraspinous ligament. When the horse’s neck and back lift correctly, this is the ligament that supports the collection and suspension.

An appropriately wide gullet (the channel between the panels of the saddle) allows the uninhibited movement of this ligament. The degree of upward bend that occurs muscularly is probably imagined by most of us to be greater than it actually is. The horse does not arch like a cat, but rather lowers its haunches when ridden in true collection. When fitting a horse that is frequently ridden in a highly collected or engaged frame, it is suggested that a degree of “lightness” be incorporated into the saddle fit. This is a very, very small amount of bridging that is practically undetectable. Most Icelandic horses have relatively short backs and are not capable of such an extreme degree of engagement, nor are they usually ridden for extended periods of time in such a frame, but that same lightness in fitting would be appropriate for those that are.

When a horse is ridden on a relaxed, loose rein, the head lowers and the nuchal/ supraspinous ligament is engaged. When the horse stretches his neck forward, the nuchal ligament is put in traction, pulling on the withers’ spinous processes, causing them to rise. This effect extends all along the horse’s back—the traction is transmitted to the tendon-like supraspinous ligament, which, as a direct continuation of the nuchal ligament, connects all of the back’s spinous processes. As all of the back’s spinous processes rise, upward and to the front, the thoracic and lumbar vertebrae follow. Think of it as being like a see-saw. The head goes down, the back comes up. Thus, the horse’s back lifts. In nature, for example, when the horse is out on pasture, this happens almost all of the time. Although the back rises, the muscles that support the saddle panels do not greatly change shape from when in a static position. In other words, the neck lowers and the saddle area lifts or comes up. The belly muscles contract.


It is correct to assume that “static fit is only perfect for standing still.” It is also the only place to begin! So much more influences the fit of a saddle, certainly not the least being the rider. Is the rider balanced? Does the rider have postural or conformational issues? Does the rider collapse to one side or the other? Thermography studies have shown that well-fitting saddles can become less than optimal under some riders, while saddles with less than perfect fits do quite well by the horse under better balanced riders. The saddle may fit the horse, but does it fit the rider? Seat depth and center location, stirrup bar placement, pommel shape and size, saddle flap length, and ride alignment all have direct impact on rider balance and comfort.

The following is a quote by Joyce Harman, DVM, MRCVS, from The Horse’s Pain-Free Back and Saddle-Fit Book: “It is important to realize that perfect fit is elusive. Once you have matched a saddle to both horse and rider as best you can, don’t worry about ‘perfect.’ Sometimes ‘good’ is good enough, especially if you ride recreationally. If, on the other hand, your horse exhibits performance or behavior problems that could be related to saddle fit, it is best to keep trying to improve the situation.”

No saddle fit should be considered complete at the static phase. If a professional saddle fitter is employed, the process should include a mounted fit evaluation. Many times the saddle will pass muster up until the rider takes a spin.

A well-fitted saddle allows the horse free and expressive gaits, especially a walk that the rider can both enjoy and participate in. Most of us reading this article have felt the walk while in a treed saddle. The movement of the horse’s hips comes up through the saddle and influences the movement of our own seat bones and hips. Some Centered Riding exercises liken the feeling to “riding a bicycle backwards.” When the equine’s shoulder movement is allowed to be free and uninhibited, then the rider can enjoy the opportunity to join in that movement through the seat bones and hips. A saddle built on a tree that is appropriate for the horse and its use should never interfere with the equine’s movement. If it does, it is the wrong saddle, absolutely.

A saddle should fit like a glove, not like a girdle. The saddle should follow the angles and contours of the horse’s back and muscles. At best it should enhance the riding experience for both partners, whether or not it is treed. At worst, it should not cause discomfort to either horse or rider. At the end of it all, the saddle is the unifying piece of equipment between two dynamic beings making an effort to move in unison. It’s a daunting thought.

Official Publication of the United States Icelandic Horse Congress (USIHC), a member association of FEIF (International Federation of Icelandic Horse Associations).

The Icelandic Horse Quarterly is published in March, June, September, and December by the USIHC as a benefit of membership. Join online at USIHC members are encouraged to submit articles and photos or illustrations for publication. Deadlines are January 1 (for the March issue), April 1, August 1, and October 1. Advertising rates and instructions are also online.

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