Biomechanical analysis of hoof landing and stride parameters in harness trotter XXXX running on different tracks of a sand beach (from wet to dry) and on an asphalt road.

@entity2133 @entity1641 @entity3126
REASONS FOR PERFORMING STUDY: Sandy beaches are often considered good training surfaces for trotter @entity1641 . However, their biomechanical effects on locomotion are insufficiently documented. Events at hoof impact have mostly been studied under laboratory conditions with accelerometers, but there is lack of data (acceleration, force, movement) on events occurring under every day practical conditions in the field. OBJECTIVES: To investigate hoof landing and stride parameters on different tracks (from wet to dry) of a sand beach and on an asphalt road. METHODS: The right front hoof of 4 trotter @entity1641 was equipped with a triaxial accelerometer and a dynamometric horseshoe. Acceleration and force recordings (10 kHz) were synchronised with a high speed movie (600 Hz). @entity1641 were driven on a sand beach where 3 tracks of decreasing water content had been delimited (from the sea to the shore): @entity3126 ( @entity3126 ), @entity3126 ( @entity3126 ) and @entity2133 ( @entity2133 ). Firm wet sand and @entity3126 were compared at 25 km/h and @entity2133 compared to an asphalt road at 15 km/h. Recordings (10 strides) were randomly repeated 3 times. Statistical differences were tested using a GLM procedure (P < 0.05). RESULTS: Main significant results were 1) a decrease in the amplitude of the vertical deceleration (and force) of the hoof during impact on a softer surface (about 59% between @entity3126 and @entity3126 and 95% between @entity2133 and asphalt), 2) a decrease in the longitudinal braking deceleration (and force) on softer grounds (50% for @entity3126 vs. @entity3126 and 55% for @entity2133 vs. asphalt), 3) a decrease in the stride length and an increase in the stride frequency on a softer surface. CONCLUSIONS AND CLINICAL RELEVANCE: Drier sand surfaces reduce shock and impact forces during landing. For daily training, it should, however, be realised that improved damping characteristics are associated with a shorter stride length and a higher stride frequency.
