There are two aspects to saddle fitting: fitting the saddle to the horse, and fitting the saddle to the rider. Each is equally important, and proper saddle fitting usually takes time. A poorly fitting saddle can lead to health problems for horse or rider, or to poor performance under saddle. For people who are not familiar with horses and saddles, consulting an expert can be a good idea, to ensure that a horse is tacked appropriately. Once riders have more experience, they can start to fit their own saddles.
The goal of a saddle fitting session is to find a saddle which is comfortable for both horse and rider. A good saddle promotes good posture for both parties, allowing for a full freedom of movement and eliminating pressure points and hot spots which could lead to pain and soreness. A well-fitted saddle can also facilitate communication between horse and rider, making it easier for the rider to control the horse.
Riders can approach saddle fitting from their perspective or the horse's when they start out, because both will be incorporated into the decision about which saddle to buy at the end. For riders, the saddle should be comfortable to sit in, and it should allow the body to sit in a straight line. Sitting in a saddle in the store can provide clues about whether or not it will be a good fit, although the fit will have to be checked again on the horse.
For the horse, a saddle should fit evenly and smoothly on the back, clearing the withers and falling behind the shoulder bone so that the horse has total freedom of movement under saddle. Some common problems with saddle fitting include bridging, in which a saddle is too flat or too long for the back of the horse, creating pressure points around the withers and loins and failing to contact the middle of the back, and constriction at the gullet, the peaked area of the saddle which rises over the withers. At least two fingers should fit under the gullet when the saddle is cinched onto the horse.
When a saddle is on a horse, it should fall evenly. If the back or front of the saddle is tilted, it is a sign that the saddle is a bad fit. On a horse with a short back, the saddle panel may be long enough to dig into the hindquarters, which is undesirable. Some horses have very flat backs, while others have sloping backs, and each type requires a slightly different saddle design. To confirm that the saddle fits snugly and evenly, slip your hand under the saddle flaps and run it along the saddle panel, looking for gaps or tight areas.
The conformation of a horse changes over time, and a saddle which fits in youth may not fit in old age. This is an important consideration when fitting a saddle, or working with a horse who has suddenly developed behavioral problems. The horse might be expressing discontent with a saddle which no longer fits properly.
Some other signs of poor saddle fit include the development of sores or white hairs on the back, dry spots when the saddle is removed instead of an even damp patch, and the sensation of rolling or tipping while in the saddle. The horse may also develop tight back muscles, which can be tested by firmly probing along the line of the back with two fingers. If the horse stays relaxed, the back is in good shape, but if the horse twitches or the muscles seem very tight, the horse may not be wearing the right saddle.
In the process of fitting a saddle, adjustments can be made to the saddle to alter the fit. Straps may be lengthened or tightened, and a saddle pad can be used to perfect the fit. However, a saddle pad should not be used to compensate for a badly fitting saddle, as a saddle pad is usually not enough to address the problems with the saddle.
Once a saddle is properly adjusted on the horse, it is a good idea to walk the horse on a lead and observe the movement patterns of the body, looking for signs that the saddle is constricting movement or creating tension. If the saddle appears to be a good fit, it is time for the rider to hop up and adjust the stirrups to see how the saddle feels on the horse. In a comfortable saddle, the rider will sit naturally straight, and there should be no pressure points around the pelvis or buttocks.