Relationship Between Saddle and Rider Kinematics, Horse Locomotion, and Thoracolumbar Pressures in Sound Horses

Saddle fit is considered to be a crucial factor for the health and performance of horses, yet there is a paucity of scientific data. The objective of this study was to determine the relationship between saddle and rider kinematics, horse locomotion, and thoracolumbar pressures in sound horses. Seven horses with asymmetric saddle position were tested before and after correction of the saddle positioning asymmetry. Kinematic and kinetic data were collected using motion capture, inertial sensors, and a pressure mapping system. Data of horses showing saddle roll to the right were normalized to represent saddle roll to the left. When comparing saddle roll with saddle correction in trot, this study found that once the saddle had been corrected on the rein with saddle roll to the outside (here: right rein), there was an increase in outside front fetlock hyperextension (P = .02) and inside hind fetlock hyperextension (P ≤ .05); there was a reduction in peak pressures after saddle correction under the inside portion of the panel in trot (P ≤ .05) and canter (P = .04), and riders showed increased thoracic side bend (lean) on the contralateral side to the direction of saddle roll (P = .02). The presence of saddle roll creates changes in fetlock hyperextension and hence likely force production, increases peak pressures beneath the panel on the contralateral side to the direction of saddle roll, and affects rider position, with the rider leaning in the opposite direction to saddle roll likely to optimize balance.