When we’re tacking up and heading out for a ride, we brush our horses off, pick their feet, check girth tightness, mount up, plop down, and head off. What we’re sitting in, and on, is often the farthest things from our mind — unless the saddle is super uncomfortable for.

And unless you’ve been taught otherwise by your trainer, the proper fitting of a saddle and why it’s important isn’t even something that’s on our radar.

So what do you need to know? First and foremost, understand that just because a saddle is comfortable for you doesn’t mean it’s comfortable, let alone a good fit, for your horse. According to Kelsey Nicholls of Addiken Saddle Fitting, “your horse’s comfort has a direct impact on his health, soundness, and performance.” Saddles that don’t fit can cause anything from lameness, to behavioral problems, to back pain, and can even put extra strain on your horse’s legs.

If you’ve bought a new or used saddle, it’s been awhile since you’ve had your saddle fit checked, or even if you’re looking to borrow a saddle from your trainer, there are a few things you can check to make sure the saddle isn’t too long or too wide or narrow for your horse. But there are two very important things to remember: this does not replace a professional evaluation from a qualified saddle fitter and the saddle needs to be tested standing still AND in motion. A saddle fit needs to be judged on how well it fits when the horse is standing still as well as how they move in it, whether or not the saddle shifts when you’re riding, and whether any behavioral problems arise.

To “static” check a saddle: After making sure your horse is standing square, place the saddle on the horse’s back. If the saddle fits correctly, the points of the tree should be 2 fingers behind your horse’s shoulder blade and the rails of the tree should be should be parallel to the horse’s barrel. To check this, lift up the seat skirt and check the angle of the tree. Next, with one hand firmly on your saddle, run your other hand under the saddle along the panels. If this saddle fits correctly, there should be contact on both sides of the panels.

Width, length, and balance also need to be checked to ensure a proper fit. If the width of the gullet is too narrow, there isn’t enough room for the spine to move, but if there’s too much room you’re working with much less weight-bearing surface area for your saddle to sit on. You’ll also want to check and make sure there is ample clearance of the pommel over your horse’s withers. For balance, the deepest part of the saddle’s seat should perpendicular to the ground. To make sure the saddle isn’t too long for your horse’s back, find the 18th Thoracic Vertebrae, which corresponds with the last rib — your saddle shouldn’t be resting beyond this point.

“It’s vitally important that each and every equestrian know what to look for when it comes to a proper saddle fit,” Nicholls says. “We should be able to identify if there is a problem and know when to call in a professional.” Your knowledge of horses needs to go beyond knowing how to tack up and ride in order to be a responsible rider and horse owner.