Is your saddle perfectly symmetrical?
Before you proudly say, “Yes, of course! I’d never have an asymmetrical saddle for my horse!”, consider this second, and equally important question: Is your horse perfectly symmetrical?
A well-fitting saddle – meaning one that doesn’t cause pain, limited movement, or even muscle atrophy – follows the shape of your horse along both sides of his spine. But according to a new study, most horses have different shapes on the left and the right back and shoulders – specifically on either side of the withers.
“Riding horses appear to be generally asymmetrical in their musculature, with greater bulk on the left side,” said Katrina Merkies, PhD, associate professor and faculty advisor for the equine degree program at the University of Guelph, in Ontario, Canada. Merkies presented the results of her group’s study during the 14th Conference of the International Society for Equitation Science (ISES) in Rome, Italy.
“Traditionally saddles are made and fit assuming horses are symmetrical,” she said. “But most of the time, that’s not true, and it leads to poor fit.”
The consequences of poor fit are obvious, according to Merkies. “The white scars that are left after a poorly fitting saddle has been used for a period of time, swelling around the withers and trapezius muscle, atrophy of the latissimus dorsi, stress lines where points of the tree have been pressing into the horse—all of these are telltale signs of the effects of an ill-fitting saddle,” she said.
Merkies’s undergraduate student, Julia Alebrand, initiated a group study investigating the level of symmetry around the withers, backs, and shoulders of more than 400 riding horses. The horses represented different ages, breeds, and sex and had a variety of different riders (demographics, disciplines, morphology). Using information gathered from specific wither measurement tools that can trace body shapes, they recorded eight measurements for each horse.
The researchers found that overall, horses tended to have more muscular development on the left side than the right. While this could be related to genetics and natural laterality, it might also have to do with the way humans ride and train them, Merkies explained. “We lead from the left; we mount on the left,” she said, suggesting that this combination of training and genetics might then lead the horses to prefer the left side themselves. “Maybe this is why it’s often easier to pick up a left lead in canter.”
The team also found major differences in back and wither shapes across breeds. Sometimes they confirmed what many horse people already know—like draft horses having shorter withers and Thoroughbreds having higher, bony withers. But they also uncovered less known trends like Arabians having shorter saddle support zones than other breeds, or higher level dressage and jumping horses tending to stand with the left shoulder farther forward than other horses.
“Taller horses, over 16.2 hands, had unique differences in their back and wither muscles compared to other horses, whereas the population of medium-sized horses included more sway backs, maybe because the saddle is too long for them and extends beyond the saddle support area, which would make their backs more likely to sway,” Merkies said.
Interestingly, they noted no traceable effects of the rider’s demographics on any of the measurements or descriptive measures, she added.
By recognizing shape asymmetry, riders can aim to have a saddle fitted to respect that asymmetry which, in the end, could actually then lead to resolving the asymmetry.
“It’s in the best interest to fit the saddle to the horse,” Merkies said. “The horse is a miraculous combination of muscles, bones, tendons, and ligaments, with a grace, ability, and agility we admire. But we can compromise all that with poor saddle fit. By contrast, however, if we can encourage more symmetrical movement by freeing up the horse under saddle, then it can lead to more symmetrical horses.”
As more general advice, Merkies said she recommends always going to a professional for proper saddle fit. “Using a saddle off-the-shelf may not provide the most proper fit for your horse,” she explained. “Employ a certified saddle fitter to fit your saddle to your horse, and make sure to have your saddle rechecked regularly. As your horse changes his muscling through exercise and training, the fit of the saddle may change.”
Dr Katrina Merkies is the head of the Local Organising Committee for the 15th International Equitation Science Conference which takes place 19th-21st August 2019, hosted by the University of Guelph, Ontario, Canada.