Lateral movement of the saddle relative to the equine spine in rising and sitting trot on a treadmill.
Authors: Byström A, Roepstorff L, Rhodin M, Serra Bragança F, Engell M T, Hernlund E, Persson-Sjödin E, van Weeren R, Weishaupt M A, Egenvall A
Journal: PloS one
Summary
# Editorial Summary Saddle slip has emerged as a potential clinical indicator of lameness, yet baseline data on normal saddle movement during ridden work remained unavailable until this study quantified lateral saddle oscillations objectively. Using simultaneous force plate, motion capture and saddle pressure analysis on seven elite dressage horses, researchers measured how much the saddle moved laterally relative to the spine during rising and sitting trot on a treadmill, then correlated this movement to specific biomechanical variables of both horse and rider. Maximum lateral displacement ranged from 14.3 mm in rising trot to 23.9 mm in sitting trot, with the findings revealing that increased pelvic height at push-off (a marker of impulsion) and asymmetries in rider pelvic roll and yaw directly influenced saddle movement—each 10 mm rise in pelvic height increased saddle slip by 1.4 mm, whilst increased rider pelvis roll actually reduced it. For practitioners assessing lameness or saddle fit, these results establish that normal saddle oscillations reflect the combined biomechanics of horse and rider rather than indicating pathology alone, meaning that interpreting saddle slip requires careful consideration of ridden movement quality and rider asymmetry alongside potential equine gait abnormalities.
Read the full abstract on PubMed
Practical Takeaways
- •Lateral saddle movement is normal in ridden horses (14-24 mm range), so modest slip alone may not indicate lameness without other clinical signs
- •Rider position significantly affects saddle stability—maintain neutral pelvis roll and controlled yaw to minimize saddle movement and improve security
- •Excessive or asymmetrical saddle movement may be a useful indicator of underlying lameness or movement dysfunction and warrants further investigation
Key Findings
- •Maximum lateral saddle movement (caudal part relative to spine) ranged from 14.3 mm in rising trot to 23.9 mm in sitting during rising trot and 20.3 mm in sitting trot in non-lame horses
- •A 10 mm increase in maximum pelvic height at push-off increased lateral saddle movement by 1.4 mm
- •Rider pelvis roll and yaw angles significantly influenced saddle lateral movement: one degree increase in roll decreased movement by 1.1 mm while one degree increase in yaw increased movement by 0.7 mm
- •Both horse and rider movement asymmetries are reflected in lateral saddle oscillations, suggesting saddle slip may indicate movement abnormalities