The effect that a saddle positioned laterally to the equine vertebrae has on rider biomechanics while cantering

unridden condition. The uneven load induced by the rider in rising trot increases the movement asymmetry of the hind limbs compared to sitting trot, resulting in more downward movement of the pelvis during the seated phase and less upward pelvic move-ment in the end of the seated phase. In training, little consideration is given to the effect that saddle position has on rider position and resultant equine behavior. The aim of this study is to objectively evaluate the effect that saddle position has on rider biomechanics. Seven horses, (1.63 -1.80m; 6 -12 years), displaying saddle roll, were assessed for lameness by a veterinarian and seven riders (6 female and 1 male) took part. Saddle fit was subjectively graded by 3 Society of Master Saddlers Qualified Saddle Fitters. Markers were posi-tioned on the mid-line of the cantle, between the two tubera sacrale and caudal aspect of the croup. Riders wore a posture jacket (Visualise TM) with horizontally and vertically positioned lines. A high speed camera (240 Hz), positioned caudally captured straight line locomotion on both left and right rein. Data was collected with saddle roll then repeated once the saddles had been corrected using Prolite shims. Using Quintic Biomechanics, 2D video analysis, left and right hip flexions were quantified. A mean of 3 repeated canter strides with a paired t-test was used to determine significance between saddle straight and roll. Saddle roll left showed a significant increase in rider's right hip flexion (t 9 ¼ 0.02, P < 0.05) (Left Hip 153.3 AE 7.26 Right Hip 141.9 AE 3.36). When straight, the right hip was significantly less flexed (t 9 ¼ 0.01, P < 0.05) resulting in improved symmetry with no significant difference (t 9 ¼ 0.16, P > 0.05) between left and right hip flexion (Left Hip 149.3 AE 10.68 Right Hip 148.6 AE 2.24). This study found significant differences in rider's hip flexion with a saddle which displayed saddle roll left.