Timing Differences in Stride Cycle Phases in Retired Racehorses Ridden in Rising and Two-Point Seat Positions at Trot on Turf, Artificial and Tarmac Surfaces.
Authors: Horan, Price, Day, Mackechnie-Guire, Pfau
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Surface and Rider Position Effects on Racehorse Stride Kinematics at Trot Retired racehorses regularly transition between different ground surfaces during daily work—tarmac approaches, turf gallop tracks, and artificial schooling arenas—yet little evidence has documented how these surfaces affect their movement mechanics. Using accelerometer-based hoof sensors worn on the forelimbs of six horses ridden at trot by the same jockey, researchers quantified landing duration, mid-stance, breakover, swing phases and stride length across tarmac, grass and artificial surfaces, with the rider adopting both rising and two-point seat positions. Landing duration proved dramatically surface-dependent, shortening by 4.4 times on tarmac compared to grass and artificial surfaces, whilst mid-stance extended by 13 ms when the jockey adopted two-point position and by 19 ms on tarmac versus artificial ground; notably, total stride duration was reduced by 49 ms on tarmac relative to turf, and stride length decreased by 14 cm on hard surfaces. These findings indicate that surface transitions impose meaningful kinematic shifts that extend beyond gait velocity, suggesting practitioners should consider ground conditions and rider positioning as variables influencing load distribution and potential injury risk, though direct associations between these altered stride parameters and musculoskeletal injury remain to be established.
Read the full abstract on PubMed
Practical Takeaways
- •Surface type significantly affects hoof kinematics during trot work—tarmac produces dramatically shorter landing times and total stride durations, which may influence injury risk differently than turf or artificial surfaces
- •Jockey riding position (two-point versus rising) alters stance phase timing; consider advising on position changes when managing racehorses with load-bearing concerns during road work
- •Stride length and landing mechanics vary substantially by surface; incorporate surface-specific warm-up strategies when transitioning between gallop tracks, roads, and artificial surfaces to minimize sudden biomechanical changes
Key Findings
- •Landing duration was 4.4 times shorter on tarmac compared to grass and artificial surfaces (p<0.001)
- •Mid-stance duration increased by 13 ms with jockey in two-point seat versus rising position (p<0.001)
- •Stride time on tarmac was 49 ms shorter than on turf (p=0.011), potentially related to reduced landing times
- •Swing phase was 20 ms longer on turf than artificial surfaces (p=0.039), with stride length correlating strongly to speed (71 cm increase per 1 m/s, r²=0.8)