Ground reaction force patterns of Dutch warmblood horses at normal trot.

This study was undertaken to establish limb loading patterns of sound horses at the trot, to provide a data base against which results for lame horses could be compared. Ground reaction force (GRF) data were collected from 20 clinically sound Dutch Warmblood horses. The data from at least 5 stance phases of each limb were averaged after standardisation to the animal's body mass and to the stance phase duration and resulted in 'representative' GRF data. The symmetry in the vertical GRF peak amplitudes, impulses and the stance phase duration comparing left and right limbs exceeded 97%. By averaging the 'representative' GRF of the 20 horses a 'standard' GRF pattern of the Dutch Warmblood horse at the trot was constructed. The GRF patterns at the trot, compared with those at the walk, showed only one vertical force peak in forelimbs and hindlimbs (11.59 N/kg and 10.21 N/kg, respectively). The retardatory and propulsory forces were distributed over the forelimbs and hindlimbs in such a way that the forelimbs contributed more to retardation (peak forces 1.13 and 0.79 N/kg), and the hindlimbs more to propulsion (-0.84 and -1.17 N/kg, respectively).