Saddle Thigh Block Design Can Influence Rider and Horse Biomechanics

The association between rider-saddle interaction and horse kinematics has been little studied. It was hypothesized that differences in a thigh block design would influence (a) rider-saddle interface pressures, (b) rider kinematics, and (c) equine limb/spinal kinematics. Eighteen elite sport horses/riders were trotted using correctly fitted dressage saddles with thigh blocks S (vertical face) and F (deformable face). Contact area, mean, and peak pressure between rider and saddle were determined using an on-saddle pressure mat. Spherical markers allowed for the measurement of horse/rider kinematics using two-dimensional video analysis. The kinematics of the equine thoracolumbosacral spine were obtained using skin-mounted inertial measuring units. Results were compared between thigh blocks (paired t-test p ≤ 0.05). With F, the contact area, mean, and peak pressure between rider and saddle were significantly higher (p = 0.0001), and the rider trunk anterior tilt was reduced, indicating altered rider-saddle interaction. The horse thoracic axial rotation and flexion/extension were reduced (p = 0.01-0.03), caudal thoracic and lumbar lateral bend was increased (p = 0.02-0.04), and carpal flexion increased (p = 0.01-0.05) with F compared to S. During straight-line locomotion when in sitting trot, thigh block F was associated with altered rider-saddle interaction and rider and equine kinematics, leading to a more consistent rider-saddle interface, a more upright rider trunk during stance, an increased horse thoracic stability and lumbar lateral bend, and forelimb flexion, supporting the importance of optimising rider-saddle-horse interaction.

Biomechanical variables in Icelandic horse riders and the effect on tölt performance: A pilot study

AIM

To identify how riding rein direction (left and right) and rider asymmetry affect tölt performance in Icelandic horses.

METHODS

Two horses were ridden in tölt by four riders on both left and right reins. Riders wore pressure insoles that measured the total absolute force (FAbs) and absolute force difference (FDiff) in their left and right feet in the stirrups. A 3D motion-analysis system recorded the degrees of side-to-side movement in the pelvis (RollP) and in the thoracolumbar region (RollT). Lateral advanced placement (LAP) and duty factor (DF) were calculated to determine tölt performance. One-way ANOVAs were used to assess the effect of rein direction on rider asymmetry variables (FAbs, FDiff, RollP and RollT) and tölt performance (LAP, DF) on a group level (n = 8). Within-subject Spearman rank correlations (ρ) were computed to determine the effect of rider asymmetry variables on tölt performance on an individual level.

RESULTS

LAP was closer to 25% on the left rein compared to the right rein (mean difference: 1.8±1.2%; F(1,7) = 16.333; p = 0.005, η2p = 0.700). In addition, DF was lower on the left rein compared to the right rein (mean difference: 1.9±0.8%; F(1,7) = 41.299; p<0.001, η2p = 0.855). Individual relationships between RollT and LAP ranged from small negative to very large positive and reached significance for one rider (ρ = 0.730; p = 0.040). Individual relationships between RollP and DF ranged from very large negative to very large positive and reached significance for two riders (ρ = 0.731; p = 0.040; ρ = -0.723 p = 0.043).

CONCLUSION

Rein direction might influence tölt performance. Individual relationships between rider asymmetry and tölt performance were highly variable and reached significance in some instances, indicating that the relationship between rider asymmetry and tölt performance is highly individual. This type of biomechanical data can be used to provide valuable feedback to guide equestrians and coaches.

Coordination variability reveals the features of the 'independent seat' in competitive dressage riders

The rider's ability to consistently coordinate their movements to their horse is a key determinant of performance in equestrian sport. This study investigated the inter-segmental coordination variability between the vertical displacement of a riding simulator and the pitch rotation of 28 competitive female dressage riders' head, trunk, pelvis, and left foot, in simulated medium and extended trot. A statistical non-parametric mapping three-way repeated-measures ANOVA investigated the influence of gait, competition level and segment on coordination variability. There was a significant main effect of gait and segment (p = 0.05), however, no significant effect of competition level. In medium trot, simulator-pelvis coupling was significantly (p < 0.001) less variable than simulator-head, -trunk, and -foot couplings. Significantly greater coordination variability of simulator-head and -foot relative to the trunk and pelvis suggested that riders can maintain stability in the saddle with their trunk and pelvis while allowing greater variability of their head and foot coupling to the simulator's vertical displacement. It is proposed that stronger coupling of the rider's pelvis relative to their other segments is one facet of the equestrian dressage skill of the independent seat. However, greater perturbations during simulated extended trot may necessitate a decrease in the independence of the rider's seat.