The Unbalanced Horse: Shims vs. Custom Flocking for Asymmetrical Backs

Ever feel like your saddle has a mind of its own, slipping to one side no matter how carefully you tack up? Or maybe you’ve noticed your horse finds it easier to bend one way than the other. While you might dismiss it as a training quirk, you could be looking at the subtle signs of equine asymmetry.

And you wouldn’t be alone. A groundbreaking 2018 study by Dyson et al. of 506 sport horses found that a staggering 47% showed underlying lameness or gait issues. The most revealing part? Their owners recognized a problem in only 22% of those cases. This gap highlights how many horses are quietly compensating for imbalances we can’t easily see.

Asymmetry isn’t a flaw; it’s a reality for most living beings, horses included. When it comes to saddle fit, however, this one-sidedness can be a source of chronic discomfort and performance issues. The challenge lies in creating a balanced fit on an unbalanced back. The two primary solutions are shimming with corrective pads and custom wool flocking. Let’s explore which approach might be right for you and your horse.

Recognizing the Signs: Is Your Horse Asymmetrical?

Before we dive into solutions, let’s clarify the problem. Equine asymmetry refers to uneven muscle development, typically appearing in the shoulders and back. One side may be more built up (hypertrophied) while the other appears hollow or less developed (atrophied).

[Image 1: A side-by-side comparison showing an asymmetrical horse’s back with one shoulder more developed than the other.]

Common signs you might notice include:

• Your saddle consistently slips to the less-muscled side.
• Uneven sweat marks after a ride, with dry patches indicating pressure points.
• Difficulty picking up or maintaining one canter lead.
• Resistance or stiffness when asked to bend in one direction.
• Your own position feels crooked in the saddle, despite your best efforts to sit straight.

If any of these sound familiar, you’re not imagining things. You’re observing a biomechanical puzzle in need of a solution.

Why a Level Saddle on an Uneven Back Doesn’t Work

Imagine placing a perfectly flat, rigid board on a sloped surface. It will tilt, creating intense pressure on the lower edge while the upper edge lifts away. This is precisely what happens when a standard saddle is placed on an asymmetrical horse.

Research from Greve & Dyson (2013) definitively links ill-fitting saddles to back pain and lameness. A saddle that “bridges” over a hollow area or pinches a well-developed shoulder doesn’t just cause discomfort—it actively restricts movement. Studies by Clayton & Preuschoft confirm that this uneven pressure directly impacts how a horse’s thoracic spine can flex and rotate, limiting their ability to move freely and athletically.

Over time, this pressure can lead to muscle atrophy, worsening the very problem you’re trying to solve (Meschan et al., 2007). It’s one of the most common saddle fit mistakes riders make: assuming a symmetrical saddle will fix an asymmetrical horse. In reality, the saddle must be adapted to create a balanced, therapeutic interface.

The Two Main Approaches: A Head-to-Head Comparison

So, how do we adapt the saddle to the horse? The two primary methods are shimming and custom flocking—think of them as an external versus an internal fix.

The Shim Solution: Quick, Flexible, and Temporary

Shimming involves using a corrective saddle pad with pockets where foam or felt inserts (shims) can be placed to fill in gaps. For an asymmetrical horse, a shim is placed on the more hollow side to lift the saddle and create a more level feel.

[Image 2: A diagram illustrating how a shim pad works, showing the shim placed in a pocket to lift one side of the saddle.]

Pros of Shimming:

• Highly Adjustable: You can easily add, remove, or change shims as your horse’s musculature develops.
• Versatile: A single corrective pad can be used with multiple saddles or on different horses.
• Accessible: It’s a non-invasive solution that doesn’t require altering the saddle itself.

Cons of Shimming:

• Can Create Bulk: Adding extra layers between the saddle and the horse can sometimes interfere with close contact and stability.
• Risk of Shifting: If not perfectly placed, shims can move during a ride, creating new pressure points.
• A “Band-Aid” Fix: Shimming addresses the symptom (a crooked saddle) but doesn’t change the fit of the saddle itself against the horse.

Custom Flocking: The Integrated, Therapeutic Approach

Most high-quality saddles are made with panels stuffed with pure wool. Custom flocking is the art of having a qualified saddler adjust the amount and placement of this wool to perfectly mirror your horse’s back. For an asymmetrical horse, the saddler adds more wool to the panel on the hollow side, effectively building up the saddle from within.

[Image 3: An expert saddler adjusting the wool flocking inside a saddle panel with specialized tools.]

Pros of Custom Flocking:

• Seamless Integration: The correction is built directly into the saddle, ensuring a stable, precise fit with no extra layers.
• Promotes Correct Development: By filling the hollows, a custom-flocked saddle distributes pressure evenly, encouraging underdeveloped muscles to grow.
• Superior Comfort: Wool is a natural, breathable material that conforms beautifully to the horse’s back, providing a forgiving yet supportive cushion.

Cons of Custom Flocking:

• Requires Expertise: This isn’t a DIY job; it must be done by a skilled, qualified saddle fitter.
• Less Flexible: Adjustments require a visit from your fitter and can’t be changed on the fly.
• Needs Maintenance: As the horse’s back changes, the flocking will need to be re-evaluated and adjusted, typically every 6-12 months.

Beyond Adjustment: The Role of Panel Design

While shimming and flocking are adjustment methods, the saddle panel’s design is what ultimately determines their effectiveness. A narrow, hard panel offers little room for error and cannot distribute pressure effectively, no matter how well it’s flocked.

The foundation for any successful fit starts with the saddle tree and ensuring proper saddle position. From there, the panel design becomes critical. A well-designed panel should have a wide surface area to maximize contact and minimize pounds per square inch (PSI) of pressure.

This is the philosophy behind innovations like the Iberosattel Comfort Panel. It’s engineered with a significantly broader, softer contact surface. This design not only distributes the rider’s weight over a larger area but also provides the ideal canvas for custom flocking. The forgiving surface allows a saddler to make precise adjustments for asymmetry, creating a truly therapeutic fit that supports the horse. This thoughtful design approach is also key when fitting horses with unique conformations, such as short-backed horses.

[Image 4: A clear photo of an Iberosattel Comfort Panel, highlighting its wide, soft surface designed for even pressure distribution.]

Ultimately, the panel’s job is to serve as the perfect intermediary between the rigid tree and the living, moving back of the horse.

FAQ: Your Asymmetry Questions Answered

Can my horse’s asymmetry be fixed?
Yes, in many cases. A combination of targeted exercises, bodywork (like chiropractic or massage), and a correct, therapeutically fitted saddle can help your horse build more balanced musculature over time. The saddle’s role is to provide a neutral platform that encourages this development.

Shimming vs. flocking—which is truly better?
The best method depends on the situation. Shimming is an excellent temporary solution for a horse in rehabilitation whose shape is changing rapidly, while custom flocking offers a more precise, integrated, and long-term solution for creating a stable and therapeutic fit. For its seamless connection and ability to promote muscle growth, many experts prefer flocking.

How often should I have my flocked saddle checked?
A good rule of thumb is every 6 to 12 months. However, if your horse is undergoing significant physical changes—gaining or losing weight, increasing fitness, or recovering from an injury—you should have it checked more frequently.

My saddle always slips to one side. Is my horse definitely asymmetrical?
It’s a strong indicator, but not definitive proof. A crooked rider or a twisted saddle tree can also cause slipping. Your first step should be to have the horse evaluated on level ground by a veterinarian or qualified saddle fitter to confirm the cause.

The Goal: A Saddle That Heals, Not Hinders

Choosing between shims and custom flocking isn’t just about leveling your saddle—it’s about creating an environment where your horse can move comfortably and correctly. The ultimate goal is a fit so balanced and stable that it encourages hollow muscles to fill in and tight muscles to relax.

Understanding that your horse might be asymmetrical is the first empowering step. By working with a qualified professional and choosing a solution that supports your horse’s unique conformation, you’re not just improving your ride. You’re investing in your partner’s long-term health, soundness, and happiness.