Riding in saddles that are too narrow or too wide likely affect thoracolumbar kinematics due to the instability and positioning of the saddle and rider, MacKechnie-Guire said. | Photo: iStock

“There is a notion in the industry that fitting saddles too wide will allow the thoracolumbar region (the part of the spine that runs from the horse’s withers to his pelvis) to increase its range of motion and improve muscular function, but none of this is supported by scientific evidence,” he began.

In his current study, he aimed to evaluate the effect of three different saddle widths (correct, narrow, and wide) on thoracolumbar kinematics (movement) in horses ridden at the canter, a gait at which this part of the spine has increased range of motion.

His team fitted 13 sound horses housed at the same facility with a validated sensor system and glued inertial measuring units along each horse’s poll; withers; 13th (T13) and 18th (T18) thoracic vertebrae; third lumbar (L3); sacrum; and left and right tuber coxae (LTC, RTC). They collected data as two similar-sized, right-handed female riders rode each horse in a properly fitted, general-purpose Kent & Masters English saddle. MacKechnie-Guire said they chose this type of saddle because of the adjustability of the tree width