How Can You Fit A Saddle On A Swaybacked Horse?

Solve bridging issues. ThinLine supports the gap.

What is ThinLine?

ThinLine is a thin, supporting, shock absorbing, non slip, breathable foam.

Where is the ThinLine?

It is sewn onto the panel of our saddle pads.

Here you can see the ThinLine foam on top of a western cotton liner pad and the images of the shimming options on-top of an english half pad.

endurance round skirt saddle fit pad


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Often, simply using a ThinLine pad will correct minor bridging issues.

If you need more, easily fill in hollow areas with ThinLine saddle fit inserts.

Every pad comes with a layer of ThinLine foam.

Simply add ThinLine shims to solve more prominent saddle fitting and confirmation issues.



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Quick Chart of Saddle Fit Issues and Solutions.


  • Hollow or Sway  Backs: Add bridging shims.
  • High Withers: Add Front shims to any pad.
  • Rider Balance: Adding a pair of shims to one side can fix balance issues.
  • Balance the saddle: Front or rear Shims, depending on your issue.
  • Slippage: Generally no shims are needed, the ThinLine Pad alone will solve this.
  • Saddle Pad Slippage: Generally your tree is too wide. Add a Booster Shim.
  • Equine or Rider Back Soreness: No shims needed, ThinLine protects both.
  • Equine Asymmetry: place both of the pair of shims on the hollow side.
  • Kissing Spine Relief: Add a Booster Shim to any ThinLine pad.
  • Treeless Saddle Pad Comfort: Add a Booster Shim to any ThinLine Pad.

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Photo: Front, Bridging and Rear Saddle Fit Shims and the Full Booster Shim.


Solutions for Saddles which Bridge or Horses with a Sway Back:

Often just a ThinLine pad is supportive enough to correct minor bridging issues.  If the bridging issue is severe you may want to add a set of bridging shims. It is not uncommon to see swaybacked horses develop more topline in a ThinLine. Historically, riders eventually remove the bridging shim.  To retain the good muscle on the top line you’ve developed continue using your ThinLine without the shims.  

Bridging Shims are available for every ThinLine Pad.   We also sell shimming kits allowing you to purchase different thicknesses and styles in bulk if you need more.



Stacking and layering saddle fitting shims.

  • ThinLine pads accept up to three 1/4 inch saddle fit shims in a single location.
  • 1/4 inch front, bridging and rear shims are the most popular but you can also purchase a thinner 3/16″ shim for bridging issues or to fill behind wide shoulders.
  • Layering sets of shims will create an even transition for major saddle fit issues. Shims may also be cut with a pair of scissors for custom work.
  • Full booster shims are 3/16 inch thin, when placed under the panel of ThinLine already on your pad you have now generated 1/4 inch of ThinLine protection.

custom saddle fit shims inserts

How to order Saddle Fitting Shims.

Select a ThinLine Saddle Pad.  Once the pad is in your shopping cart, scroll down and you will see a product called “Add Saddle Fitting Shims To The Pad In My Cart”, simply add the shims you need.

Image: Booster Shim Inserted into Pad

The entire area under the ThinLine portion accepts up to 3 sets of 1/4 inch shims in one area. There are no “pockets”, allowing you to place stack and create gradual transitions between shims.

Saddle fitting with this with shock absorbing foam provides comfort and protection for horse and rider.   Now you simply need to find the pad that fits the dimensions of your saddle and the style that fits your lifestyle.  Read on if you need more detailed saddle fitting information.

Bridging saddle fit issues.

  • Versatile Shims fill in hollow areas
  • Top shock absorbing materials protect backs
  • Open pocket allows rider to create custom fit
  • Renewed saddle balance enlivens confidence
  • Equine and rider back soreness reduced or eliminated
  • Asymmetry issues solved
  • Kissing Spine relief


saddle pad breathable ventilate


Shims slide in under the ThinLine panel.

Shimming to create comfort for the swayback horse is not complicated but riders need to know what is important.

A swayback can cause soreness to a horse’s back because most saddles will “bridge,” putting the rider’s weight only on the front and the back of the saddle, creating abnormal pressure points, especially over the shoulders and loins. On the other hand, poor saddle fit can also contribute to swayback, as the horse will alter its stride and movement, including hollowing its back, and raising its head to avoid pain. 

Top three things to know about saddles that bridge:

  1.  The saddle pad should have an open pocket, allowing you to place the shim exactly where it is needed. Saddle fitting pads with either closed off pockets or bridging shims sewn into a pad can actually cause more damage if the placement of the shim and the thickness of the shim are either in the wrong place or too thick.
  2. The shims should be available in varying thicknesses and should have the ability to be stacked.  If you correct the painful saddle fit your horse should begin creating a healthier top line.  The goal is for you to reduce the number of shims as your horse gets stronger.
  3. Less is more. Start slowly. Use one set of shims, if the saddle is still bridging add a second set of shims and continue slowly.  Over shimming will make the sway worse. 

ThinLine has invested years in understanding how materials and designs can be effectively used to make swaybacked horses more comfortable or just to make any saddle fit better on the average horse.  Our helpful staff is here for you if you have further questions.  All of our shims and pads have a 30 day guarantee – feel free to purchase shims and return those you do not use. 1-888-401-9101.


Signs of Poor Saddle Fit on Swayback Horse:

  1. Saddle Sores: caused by friction (movement of the saddle) or pressure. Girth and/or saddle are too tight or too loose and begin to rub the horse.  Friction can also be caused by an imbalanced rider, or incorrect saddle placement.
  2. White Hairs: are caused by too much pressure in a small spot.  The pressure stops blood flow, kills the sweat gland and causes hair to turn white.
  3. Dry Spots:  after you ride the horses back should be evenly wet where the saddle lies.  Dry spots suggest there is either too much pressure or not enough contact in one spot.
  4. Muscle Atrophy: your saddle is probably pinching the horse.  This could also be caused by poor riding or riding too long on unfit horses.
  5. Bridging: this is when the panels at the center of the saddle do not have even contact with the horses back.  This indicates that either the saddle tree is too straight for the horse’s back, or if the saddle fits otherwise correctly, the horse is showing signs of swayback.

There are ways to accommodate saddle fit for a saddle that bridges.  If a slight bridge exists, then use a shimmable pad with bridging shims inserted to “fill in” the gap.  Contact of the saddle panels on the horses back must be even along the top-line.  If the horse is a true sway, then this will make the horse more comfortable and offer a more permanent solution.  If the horse is only displaying signs of a sway from lack of correct muscle development, then using the shims will allow the horse to move more comfortably and correctly so that those muscles can be developed and the shims may eventually be removed.

ThinLine has several thicknesses of shims and they may be stacked so riders can remove a layer at a time when the horses back begins to strengthen and lift.

Proper saddle fit, for a horse with a swayback or not, will equal a safe, relaxing ride.  You don’t have to be an expert to tell if you have a bad saddle fit for but it is always advisable to have a professional check.  If you’re certain you have a saddle with the correct gullet size for your horse, paying attention to how your horse acts and how your body feels will let you know if you’ve got the right fit.


How do I know ThinLine is delivering the comfort and protection my horse needs?

Once you receive your Western felt saddle pad liner, ride in it for at least a week.  At first, you may simply notice things like; “my horse was great today, my seat and aids were soft and effective”, great job! you are on your way.  You will see a daily improvement. But, this can be a bit subtle in the beginning.  How to check out your pads effectiveness:  After at least a week of riding daily, begin your warm-up with the ThinLine.  Once you are warmed up, remove the ThinLine and ride.  This is when you will see just how much your horse is loving his felt saddle pad.

Money Back Guarantee:  

All ThinLine products may be returned for a full refund within 30 days. Of course, we would prefer you give us a call 1-888-401-9101 often, just a little one on one assistance will rectify what is not working for you.  Around the world, this product has helped both riders and horses work happier together. We hope our 30-day satisfaction guarantee will help you have the confidence to try this amazing material.

What is Sway Back?
Lordosis, or more commonly referred to as “swayback”, is when the span of the back dips excessively in the center of the top line.  It is caused by weakness and laxity/stretching of the supporting ligaments along the horse’s spine, often with weakness and loss of bulk/tone in the top line musculature.

Most way backs are not congenital,  are not a true sway.  Often the sway is the result of lack of muscle across the top line: building back muscle will reduce or eliminate the sway if it is not congenital and will improve it even if it is.

And proper riding and saddle fit are the biggest keys to comfort and performance. Conformation plays a role. Horses with long backs prone to back problems in general, including swayback. Horses with high-set necks and a high head carriage may be at greater risk because this way of moving tends to hollow the back.  ThinLine will encourage horses to lift their backs and lower their heads resulting in improved muscle tone.


All our pads, except the basic ThinLine, are available with bridging shims. Click logo to shop.

How Can You Fit A Saddle On A Swaybacked Horse?