Near enough isn’t good enough when it comes to saddle fit in horses, the findings of a British study suggest.
Researchers set out to learn more about the effects of the saddle tree width on back and limb function, saddle pressure distribution, and muscle dimensions where the saddle comes into contact with the horse.
Russell MacKechnie-Guire and his colleagues, writing in the journal Animals, say that determining the correct saddle fit is essential to optimise the interaction between the horse and rider, and reduce the risk of back problems or loss of performance through poor saddle fit.
Although there are industry guidelines on correct saddle fit, laid out by the Society of Master Saddlers, some saddle fitters (and others) choose to fit saddles that are wider than industry guidelines.
They do so on the assumption that increased saddle width will enhance equine locomotion and allow the horses’ thoracolumbar spine — that’s the area covered by the saddle — to function unhindered.
The researchers describe the thoracolumbar region as a dynamic platform on which a saddle needs to be positioned without causing hindrance or restriction to the horse.
The underside of the saddle should conform to the dynamics of the horse’s thoracic region and the upper side should conform to the rider’s pelvis and thighs.
For their study, the researchers quantified the effects of a saddle that was one width-fitting wider and narrower (based on the Society of Master Saddlers industry guidelines) on the function of the thoracolumbar spine, the associated muscles, equine locomotion, and saddle pressure distribution.
Fourteen warmblood sporthorse geldings were used in the study. Two experienced female riders were randomly assigned to ride them. Ten new general-purpose saddles, with an interchangeable gullet system, were used for the experiment.
Each saddle was properly fitted by a Society of Master Saddlers qualified saddle fitter. Each was then used for 10 hours before the study to allow the flocking to settle. Adjustments were then made, as appropriate.
The order of saddle fit was randomized and blinded to all technicians, riders, and veterinarians. At some stage throughout the experiment, each horse was ridden in a correct, wide, and narrow saddle once. A 10-degree difference between tree widths was used.
The study rides involved a 15-minute warm-up, followed by a prescribed trot and canter protocol on an indoor arena, during which each horse’s kinematics were quantified along with saddle-horse kinetics using sensors.
Each saddle fit was then evaluated independently by five suitably qualified individuals.
It was found that a saddle that was one width-fitting wider and narrower affected the function of the thoracolumbar spine.
The wide saddle resulted in concavities in the muscles around the T13 vertebra — that’s a little behind where the stirrups are attached — and further back at T18 when using the narrow saddle.
The wide saddle caused areas of high pressure under the forward part of the saddle and the narrow saddle caused areas of high pressures in the back part of the saddle, they reported.
The wide saddle reduced flexion-extension at T18. Additionally, in the wide saddle, axial rotation was increased further forward at T5 and decreased at T13 and L3.
“These findings would be in contrast to the belief by some saddle fitters that increased tree width allows for increased spinal kinematics,” the authors said.
“It is essential that the correct saddle fit is achieved for each horse and rider combination in order to optimise the horse-rider system and reduce the risk of back-related problems or loss of performance that may occur as a result of incorrect saddle fit.”
They said that although the English saddle has been shown to effectively distribute saddle pressures, the orientation of the wide saddle will likely affect the performance of the saddle in distributing the pressures effectively.
Wide saddles generated areas of high pressures close to the midline of the equine spine in the region T10–T13 at both trot and canter.
Subjective observation also showed the wide saddle was unstable, which was even worse when cantering.
When riding with the narrow saddle, the front part rises, meaning the seat of the saddle is not parallel to the horse’s back, causing the saddle to rock backwards. Saddles that have four points of contact are defined by saddle fitters as bridging.
Dynamically, the four points of contact may be better represented as a rocking motion, front to back and side to side.
“In either case, reduced contact beneath the middle region of the saddle can be seen.”
In their experiment, the researchers found areas of high pressures under the rear part of the narrow saddle, which was associated with concavities in the muscles around T18.
The researchers said horse owners should consider the effects that tree width has on the horse and seek regular professional advice to ensure optimal saddle fit.
“It is hoped that the findings from this study and those presented elsewhere will be used to further the understanding among saddle fitters about the importance of fitting saddles of a correct width.”
MacKechnie-Guire is with Centaur Biomechanics in Warwickshire and The Royal Veterinary College. His fellow researchers were Erik MacKechnie-Guire, also with Centaur Biomechanics; Vanessa Fairfax, with
Fairfax Saddles; Diana and Mark Fisher, with Woolcroft Saddlery; and Thilo Pfau, with The Royal Veterinary College.
The Effect of Tree Width on Thoracolumbar and Limb Kinematics, Saddle Pressure Distribution, and Thoracolumbar Dimensions in Sports Horses in Trot and Canter
Russell MacKechnie-Guire,Erik MacKechnie-Guire, Vanessa Fairfax, Diana Fisher, Mark Fisher and Thilo Pfau.
Animals 2019, 9(10), 842; https://doi.org/10.3390/ani9100842