Ground reaction forces and limb function in tölting Icelandic horses.

Abstract

REASONS FOR PERFORMING STUDY: Gaited horses employ 4-beat stepping (singlefoot) gaits that extend into speeds typical of trots. Ground reaction force (GRF) patterns of these specialised gaits have not been reported; therefore, appraisal of these gaits using nongaited horse kinetics may lead to clinical misjudgements. HYPOTHESIS: GRFs of t&#xf6;lting Icelandic horses will be comparable in profile and magnitude with those of trotting horses. METHODS: Forelimb and hindlimb GRFs were obtained for 10 Icelandic horses ridden at a t&#xf6;lt. These data were evaluated across 3 speed ranges: <2, 2.5-5 and >5 m/sec. RESULTS: Virtually all vertical force tracings were single-peaked. Forelimbs typically had greater peak vertical forces and impulses compared with hindlimbs. Support duration and forelimb vertical impulse were correlated negatively with speed, whereas peak vertical, braking and propulsive forces and hindlimb braking and propulsive impulses were correlated positively with speed. CONCLUSIONS: GRF profiles of t&#xf6;lting Icelandic horses are more similar to profiles of trots than walks, suggesting that t&#xf6;lts follow bouncing mechanics. POTENTIAL RELEVANCE: Greater overlap of limb support in 4-beat gaits (even at high speeds) is associated with lower peak vertical force magnitudes of t&#xf6;lts compared with those reported for trots at comparable speeds, which may help limit the occurrence of overloading injuries in Icelandic horses.