Reprinted from The Icelandic Horse Quarterly: Issue Two 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

The phrase, “Location, location, location,” is often heard in reference to real estate. But the same phrase very much applies to saddles and saddle fitting. It seems deceivingly simple that the saddle goes on the horse’s back. But before you tack up for the next ride, you might want to check your “borders.” And I don’t mean your backyard.

A good place to begin might be with a better understanding of the anatomy of the area directly effected by saddle placement, starting with the shoulder. It is estimated that approximately 80% of horses have larger shoulder muscling on the left. It is similar to most humans being right-handed. It’s a function of nature and usually poses no major fitting issues. Occasionally a horse will be so dominant in one limb or the other, that the more developed shoulder does become a fitting issue, and here we have the birth of a whole other article! The point though, is that one side will have a different fit than the other. It is never prudent to check fit on just one side of the saddle. It’s similar to trying on one shoe.

The top part of the scapula is cartilage not bone. It is this cartilaginous extension that can been seen on either side of the withers as the horse moves.


The shoulder, or scapula, is not just bone. A half-moon shaped piece of cartilage sits atop the bony part and is what we see on horses that have visible withers. A saddle that pinches in this area can cause damage to the cartilage. Studies using MRI and CT scans have shown that if the saddle fit is harsh enough, the results can cause the cartilage to be sheared off in places.

This information helps to underscore the importance of using a saddle with the proper tree angle. A saddle that fits parallel to the horse’s sides won’t allow the shoulder blade to move correctly once the saddle is girthed up. There should be some space at the top allowing for a proper range of motion. A three to six inch range of motion at the scapula head is what is known to be common in many horses. As far as I know, these are not necessarily gaited breeds. While I don’t have data to support my claim, I would think that Icelandic horses in free, extended gaits would have shoulder rotation more towards the upper end of that range. Limiting the scapula's motion translates directly to short, choppy strides, tripping, hesitation to go forward, and a long laundry list of other movement issues.


Because of the shoulders’ range of motion, the location of shoulder nerves and the more fragile cartilage along the top of the scapula, the saddle must be placed a few fingers’ width behind the shoulder muscles. If we were talking about a breed such as thoroughbred, it would be that little hollow just behind the ridge of shoulder bone. Icelandic horses rarely have that visual landmark, but with some gentle palpation, it is fairly easy to locate. Consider this the “front border” of the area where the points of the tree can be placed. Some leather may extend past this border (such as some of the flap), but the foundation of the saddle—the tree and thus the points of the tree—must not.


And where is the back border?

The saddle must not go beyond the last rib attachment as there is no weight-bearing support structure.

Any horse has only so much weight-bearing surface area. The second border is dictated by the attachment of the last rib. Horses have 18 thoracic vertebrae and 18 ribs. The ribs sort of bow or curve out and then back in where they attach to the spine. Look at your horse’s flanks and note where the hair changes direction. The hairline almost points upward as if indicating where the last rib is located. You can palpate along this line, locate the rib, and follow it up. Where the rib attaches is where the saddle must end. After this attachment, the transverse processes and lumbar vertebrae are without any other support. This area does not have the structure and strength required to bear weight. When a saddle that extends into this area is used repeatedly, “saddle lameness” very often occurs. The thoraco-lumbar junction, the portion of the spine accessed when engaging the hind quarters, should not be restricted by a saddle or rider. If a rider experiences difficulty in getting the horse to “drive from behind,” a closer look at the saddle fit is a good first step.

Cross section of an equine vertebra. The saddle gullet must accomodate the span of the spinous and transverse processes.


Okay, so now we have an idea of the front and the back of the saddle area. There are two other borders to be determined—the “top” and the “bottom.”

The top border of the saddle fit area is dictated by the spinous and transverse processes of the vertebrae and by the paraspinal ligaments. A cross-section of the equine spine looks somewhat like a “t.”

What we feel on the top of our horses’ backs are the spinous processes. Branching off from these on either side are the transverse processes (the cross of the “t”). Running along the channels formed by these bones are ligaments and nerves. Without wordy explanation, you can see why these structures should not be impinged upon. This anatomy is fairly easy to feel, but you may be surprised by how wide it can be. It’s not unusual for the span to be three inches wide or more. The channel or gullet of the saddle must accommodate this width and the top edge of the panel should clear the span by about one-fourth to one-half inch.

The rib heads form the lower weight-bearing border for the saddle.


The bottom border is defined by the rib heads and a ridge of muscle insertion. The rib heads attach to the spine several inches below the top of the horse’s physical back. The muscle structures that lie along this area are strong enough to handle the weight of the rider and saddle. You can feel the rib attachment if you gently rake your hand with slightly open fingers from the top of the horse’s back until you come to a discernable ridge several inches down. This is the rib head attachment. The saddle panels should not extend below the attachment.


So now the borders have been established. You can actually mark them on your horse using chalk or washable markers. Take your saddle and lay it on the neck of your horse. Put one hand lightly on the seat of the saddle and with the other hand held open against the pommel push gently, but firmly, until the saddle “seats” itself. It is a very clear feeling. If the saddle will not seat but rather continues to slide back over the croup, the saddle does not fit. If the saddle seats but the billets do not align with the heart girth (the anatomical groove where the girth should be placed), you might consider having the billeting system changed by a saddle maker. Moving the saddle to accommodate the girth means that the saddle is not correctly seated and so, essentially, doesn’t fit. Many saddle fitting problems arise from attempts to force the girth to go further back on the horse than its natural conformation dictates. I’ll write on this subject in greater detail in the near future. If your saddle seats securely within the borders, and you know there aren’t other fit issues such as bridging, pinching, etc., do the happy dance and go out and ride.

The back span on Icelandic horses can be quite deceiving. Horses that have been labeled “long backed” can, in fact, have a long spinal column, but the area where a saddle can be supported may be less than on another horse that appears to be “short backed.” By palpating and learning your individual horse’s anatomy, you get to know your riding partner that much better. Understanding the saddle boundaries is critical to the comfort of the horse and the quality of your riding experience. For a few minutes’ time you’ll get an amazing amount of useful knowledge. Now go buy some sidewalk chalk and mark up your horse! It’s a good exercise for you, and it’ll keep the neighbors wondering. Again.

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

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