Researchers at the Royal Veterinary College’s Structure and Motion Laboratory in the United Kingdom examined the effects of three common hacking surfaces (asphalt, gravel and grass) on foot placement, movement symmetry and hoof impact deceleration during the walk and trot.
Six clinically normal pleasure horses (a warmblood cross, three cob crosses and two ponies) were used for the study. During exercise the horses were outfitted with one hoof-mounted accelerometer and four body-mounted inertia measuring devices while their movement at the walk and trot was recorded with high-speed video equipment from front, back and side views.
As the surface firmness increased from grass to gravel to asphalt, the vibration power and frequencies increased, and vibration power was higher at the trot compared with the walk. Vibration frequency, however, remained unchanged. Poll movement asymmetry was greatest during trotting on the grass surface.
At a walk, a flat dorso-palmar hoof placement was most common. However, medial-lateral placement was more variable at a walk, and hoof placement from both perspectives varied more at the trot. Surprisingly, there were no differences detected for lateral-medial or dorso-palmar foot placement (includes landing pattern) or stride time among the three surfaces tested.
— Barstow A et al. EVJ 2019;51:108-114