Step 1: How to Determine the Correct Seat Size for the Rider

and Why Your Horse Cares.

The first consideration when selecting a saddle is the selection an appropriate horse.  A rider needing a saddle that is larger than a horse’s usable back must consider riding a different, longer backed horse. This can be a difficult decision as we bond and become emotionally attached to our horses. We want to be kind to them, but we also want to enjoy using them. If a horse is too small, or too short backed for riding, perhaps driving is more appropriate. Or, perhaps the horse should be used by a smaller rider who uses a smaller saddle.  And sometimes, if the saddle is only slightly too long (an inch or less), it can be modified to fit within the usable back.

The seat size of an English style saddle is measured from the center of the saddler’s nail to the center of the cantle. Use a yard stick or, if using a tape measure, hold it taut so that it doesn’t sag.  This tells you the size of the seat…not if it fits.  Common sizes are 17” or 18” but many riders are smaller or larger and need smaller or larger saddles. Many saddles are available in ½” increments, like 18 ½”.

The seat size is the second consideration. It must fit the rider’s pelvis and butt. When shopping for a saddle, a rider must sit on saddles. Lots of saddles. ..friends’ saddles, new saddles, used saddles, and saddles at a local tack shop.  After a saddle is balanced on the fake horse, mount up. (Remember, it is not girthed on, so don’t use the stirrups.)  Lift your knees so that your thighs are parallel to the floor. Wiggle around a bit so that your butt slides down to the lowest part of the seat…the sweet spot. Now, without touching the saddle with your hands, drop your legs.  Tall riders often develop the habit of pushing themselves rearward in order to fit long legs onto the flap. Don’t do this.  If this is necessary, the saddle does not fit. The seat should fit the rider’s butt and the flaps should fit the rider’s legs. The rider shouldn’t self-adjust to fit a saddle.

In a correctly fitted saddle, the width of 4 fingers fits behind the back edge of the rider’s butt and the edge of the cantle.  Four fingers should also fit in front of the pubic area and the front edge of the saddle. But seat size is only a small part of correct fit… a starting point. (More on this in future posts.)

Since fit to both horse and rider fit is important, the length of the horse’s usable back must be determined. The saddle must allow room for shoulder movement and not rest on the horse’s kidneys. It should be placed 2 fingers behind the bulge of shoulder muscle with the back edge of the panels resting on or before the 18th rib.  This area is called the usable back.

The 18th rib is the last rib strong enough to support a rider’s weight.  The 18th rib can be found by following the direction of hair growth on the horse’s back. Hair grows downward from the spine. The hair grows forward from the hips.  At some point, the downward growing hair meets the forward growing hair forming a “Vee” with swirl of hair at the tip. Follow the point of the “Vee” upward to the spine. This is where the 18th rib attaches to the spine.

An appropriate saddle for the rider fit must fit within the horse’s usable back? If it does, great! If it doesn’t, the rider should NOT select a too small saddle with the belief that she will lose weight and eventually fit into the saddle. (It doesn’t happen.)  Or that the horse’s comfort is of primary importance and that rider will suffer discomfort as long as horse in comfy. (also doesn’t happen). Even if a saddle is well fitted to a horse, it will not fit when ridden by a too big rider. The rider’s weight will no longer be evenly distributed across the length of the panels.  Don’t do this.  Neither horse nor rider will be happy.

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