The Sweatpants Theory of Saddle Fitting

Notes for a presentation to a group of equine massage therapists, August 2018.  

1.  The rules of saddle fitting are made up, but space, mass and gravity are real

People tend to evaluate saddle fit by what they can see from the outside, often fixating on the panels of the saddle because they are visually accessible. But what carries the rider’s weight and transmits force is the bearing structure inside that you can’t see, which is the tree.

To be fair to the horse, you need to think about the horse’s experience of weight-bearing when force (rider mass multiplied by velocity in motion) is being transmitted through the wood and steel structure of the tree. The panel essentially floats the tree, providing some degree of cushioning, and helps fill the negative space where the shape of the body differs from the shape of the tree. But the tree, not the panel, is the foundation of good fit. The panel can enhance or detract from tree fit, but nothing you can do with the wool in a panel will compensate for a tree problem.


2.  The best any saddle can ever be for a horse is neutral

Neutral means that the saddle doesn’t impede the horse in using his back in a biomechanically efficient way, and that the muscles supporting the rider’s weight receive sufficient blood effusion to function optimally under the weight and impact of a rider in motion.

The mere act of carrying a rider alters the shape and relative position of the spinal skeleton. Blame the pesky trio of space, mass and gravity.

To counteract the effect of the weight of a rider on the back, the horse must support the spine from below by engaging the massive sling of core muscle. This is crucial to engagement, throughness, working over the back, self-carriage – all of the things we supposedly strive for in our riding. It should be the bedrock of our training objectives, even though it’s highly questionable whether it means anything these days in competitive dressage. But most importantly, the ability to engage the core and lift/support the spine to counteract the mass of a rider is critical to long-term soundness in a ridden horse.

When the core engages, the back gets wide and flatter, and this is a good thing. But it also complicates the physics of saddle fit in the sense that you have a rigid structure – the tree – distributing weight over a living surface that is changing shape throughout the horse’s range of motion. Flexible trees? An appalling idea; think about why. (Hint: Dispersion of impact.)

A neutral saddle does not convey unintended signals to the horse (as opposed to intentional seat aides from the rider). The most common saddle fit issues – and possibly the worst in terms of long-term, body-wide consequences for the horse – are related to trees with insufficient space between the stirrup bars, or rails that are too steep between the stirrup bars for the horse to be able to lift and widen the back.

Many, many saddles on the market are built on trees that are too steep and too curvy, constantly conveying this message to the horse: “The more you engage your back in throughness, the tighter you will get squeezed between the stirrup bars.” Many horses compensate by restricting their range of motion, flattening the back, resisting the contact, and not lightening the forehand or moving the hind legs vertically with no forward reach. In other words, however much they may actually want to be back movers, horses adapt to the constant feedback of a stingy, marginal saddle fit by morphing into leg movers.

If you really want to see my head explode, say, “I have a wide warmblood who’s a big mover and I can’t ride him properly unless I’m sitting in a deep seat with a narrow twist.” Tragically, many riders unwittingly shut their horses’ backs down completely, to the point where horses attempt to immobilize an SI joint that has been put under tremendous postural strain, stiffening the muscles of the lower back like a splint around the sacrum.

This occurs shockingly often even at the very highest level of the sport. And it’s not just the horse’s back that suffers skeletal and muscular stress. If the horse cannot engage the back in a proper posture to move through a healthy range of motion, then she can’t load the hind joints levelly. This is why watching the range of motion of the ridden horse, and focusing on the range and articulation of the limbs, is such an important clue about the horse’s experience of a saddle.

And while I’m on the subject: I effing refuse to accept that upper level dressage horses need every joint in their bodies injected every six months to stay sound. The point of dressage should be to build strength and grace. To see (if you’re really lucky, to feel) a horse at any age or level of training moving freely forward without tension or stiffness, and all gears meshing smoothly is absolutely awesome. But no matter how good the horse’s saddle, and the pit crew she has to keep her parts smoothly, forcing a back mover to become a leg mover is going to result sooner or later in a broken horse. Sad.

If you take one thing away from today it should be this: If the tree doesn’t allow the back to engage and get wider and flatter without punishing the horse for lifting his back, then the saddle doesn’t fit. And if the rider finds the power of the lifted back too daunting, she really should be riding a different horse.


3.  Good saddle fit can’t be defined by what you can see from the outside

The tree is the bearing structure, and its geometry is strict because all dimensional aspects of the tree are interrelated. You can’t adjust related distances willy-nilly in a bearing structure and expect the structure to distribute weight evenly any more than you can plug numbers into an equation randomly and expect a correct solution.

BTW, no tree is fully adjustable in the beneficial ways that the marketing suggests, though there’s plenty of scope for adjusting trees in ways that can do the horse great harm.


4.  A horse’s fit requirements can’t be determined accurately by measuring

The shape of the horse’s back changes as soon as it is loaded with the mass of a rider, and it changes shape throughout its range of motion. So how useful is it to use a device to take 85 measurements of a horse’s back with the intention of making a custom saddle to fit? I wouldn’t bother unless the saddle is only going to be used on the horse in the cross ties with no rider aboard.

The terms often used to describe a horse’s width or a saddle’s width (medium, wide, etc.) have no quantifiable meaning so we should really banish the “w” word from the language of saddle fitting. It is much more useful conceptually to think about where horses are steep and where they are flat.

The grade of steepness or flatness of the horse’s back is only somewhat quantifiable but still somewhat useful in matching an inert bearing structure to a live surface and structure; the nomenclature of tree shape and back shape are certainly tricky, but important; but all the terms we use to describe horses and saddles using “width” are rubbish.

We need to think about saddles as fitting within a tolerance, without too much shape specificity. Think about what it would be like to do yoga class or go rock climbing in your skinny jeans, no matter how perfectly they fit.

Just as you want shoes that will still fit you after your feet are swollen from a 10-hour flight, you want a saddle to fit with a tolerance for the horse’s back to change shape throughout the range of motion, for the muscles to grow dimensionally during exercise through healthy effusion of blood, and for the top line to become well developed over time without necessarily needing frequent changes to your saddle. So think sweatpants, not skinny jeans.

You may not be able to get two saddle fitters in the same room to agree what day of the week it is, let alone see eye-to-eye about what good saddle fit even means, but to me it will always mean that the horse can move comfortably through a full range of motion with as little distraction as possible from the saddle. And to confirm this, the fit must be evaluated with the saddle loaded and the horse in motion.


5.  The more complicated the horse’s back, the simpler your solution needs to be in order to work

Some horses are much more complicated to fit than others. In the face of weird body proportions, think sweatpants, not skinny jeans. Think generic horse- shape and please put the notion of “custom” way out of your mind.

A plain, flat, straight-forward tree is usually going to be a much better friend to a horse’s back than a complicated “custom” fit, especially one that comes out of a mold as a one-size-can-be-magically-adjusted-to-all synthetic tree. Have you ever wondered what “custom” even means in a saddle?

The trees in English riding saddles come in two basic types: laminated wood trees and injection-molded synthetics. These are far more different from one another than most people realize. Saddles built on one of these tree types should be far cheaper than saddles built on the other type, but that’s often not the case.

Some trees are just born more horse-shaped than others. Many of the old British blocks – the solid molds that the laminated layers of wood are formed around – are kind of brilliant in their utter average-ness. This is not to suggest that there is any one tree or type of tree that fits every horse, but in a general way, some of the old trees are surprisingly versatile to fit to horses, while many of the newer trees that are in wide use these days are designed primarily for rider appeal.

 As a general rule of thumb, I would rather err on the side of too wide, and always on the side of too flat. Those are spatial issues that have work-arounds, but there’s no fix for too steep (often identified as too narrow) or too curvy. The last thing you want is for a horse who is trying to lift his back to hit up against an uncomfortable curvature in the tree or stricture between the bars that signals, “The more you lift your back, the worse this is going to be!”


6.  It’s long past time to bin the myth that all saddles should fit on their own without the use of anything besides a thin fabric pad

Padding is often used inappropriately, but that doesn’t mean that there are no appropriate uses for it. There is plenty of evidence (albeit not much in the public domain) that shock absorbent padding can enhance blood effusion and help correct balance problems in the saddle in some instances.

It doesn’t make sense spatially to build a structure down into “negative” space. Horses with atrophy or undeveloped top lines may have hollow areas that don’t conform to the contours of the tree, but as long as the tree is flat enough and a decent match in shape for the back, you can often use anti-concussive padding to level the balance and fill the horse out to the shape of the tree.


7.  The Last Word

Be reality-based, not rules-based, in evaluating saddle fit. There is a reality-based reason for everything. The horse knows what’s real. Listen to the horse.

Do not hesitate to call BS when you are told by a trainer, vet, chiropractor, owner, sales rep, or – heaven forfend – a saddle fitter that a particular saddle “fits” and the horse, when ridden, is telling you otherwise. Any number of things can cause a horse to experience discomfort from a particular saddle, even if it appears to fit brilliantly. It could be pressing on sensitive a nerve bundle, or there could be an inflamed facet that one saddle aggravates and another saddle happens to miss by a millimeter.

Likewise, many excellent fits may look superficially flawed to someone who has a picture in his or her mind of what a saddle is supposed to look like if it fits. Try really hard to see what’s really there, and consider that there’s always a terribly real possibility that a saddle that looks perfect in the crossties may end up being a sh**show when it’s on the horse with weight in it. Or the converse. I’ve sometimes seen saddles that I dismissed as obviously awful that the horse loved like an old pair of slippers. Above all other things, watch for cues in the way the horse moves; in his facial expression; in what he does with his back and hocks in the first few steps away from the mounting block. Does he move like he’s wearing sweatpants or skinny jeans? Watch footfalls from behind for clues about what’s going on in terms of back comfort. Slow motion video is priceless for this purpose.

A great deal of back discomfort will show up in unlevel loading of the hind end. This is because horses are quadrupedal, and the back is their drive chain. If they can’t use the back through a full range of motion because they are guarding against discomfort, they can’t load the hind limb joints levelly either. Uh oh.

And remember this: There is only one hard-and-fast rule that applies to every horse: They didn’t evolve over 30 million years to be weight-bearing.