Kinematics of the distal forelimb during the stance phase in the fast trotting Standardbred


Department of Anatomy and Histology, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden.


Fast-trotting Standardbred horses were filmed along a straight on an oval dirt track. Five consecutive stance phases were analysed to describe the plantar kinematics of the distal forelimb. Rapid changes in the geometry of the distal forelimb occurred during the early stance phase. The hoof segment was initially compressed vertically and moved in the direction of the horse. In general, the angular displacement of the fetlock joint was a smooth curve with 2 specific deviations in the early stance phase. The deviations are suggested to be related to the braking of the hoof and activation of the flexor muscles of the distal forelimb. A rotational dissociation occurred between the antebrachial and metacarpal segments due to a delay in braking caused by the carpus which preceded the maximal overextension of the carpus. The early stance phase changes in the distal forelimb suggest rapid changes in the internal forces of the limb and should be of importance to the orthopaedic health of Standardbred trotters.