The effect of shoeing on kinetics and kinematics during the stance phase.

The increasing range of of horseshoes and hoofpads makes it important to be able to evaluate their influence on performance and stress in the locomotor apparatus. The aim of this study was to describe the changes in ground reaction forces and locomotion pattern during the stance phase due to the application of a standard iron shoe. Six Swedish Warmblood horses were evaluated kinetically and kinematically before and after they were shod with an 8 mm iron shoe. Data were used to calculate ground reaction forces in the vertical and craniocaudal directions, point of application of the force, hoof segment angle and hoof joint, pastern joint, fetlock, carpal and tarsal angles. Finally joint angular velocity and landing velocity of the hoof were calculated. During the initial phase of the stance or the concussion phase, the horses altered the conditions of the limb, as reflected by hoof-landing velocities. Concussion-dampening mechanisms of the distal limb subsequently were altered. In the nonshod condition, the coffin and fetlock joints rotated more rapidly in the forelimb and less rapidly in the hindlimb, while earlier proximal off-loading by the carpus and tarsus resulted in a decrease in initial horizontal loading at the hoof. It was concluded that horses accustomed to standard iron shoes demonstrate slight but significant differences in the movement and loading of the distal limb due to shoeing. Though the main differences were related to the concussion phase of the stance, even mid-stance loading and roll-over were altered. The study provides a basis for further investigation of the effect of various farriery techniques on the hoof and movement of the horse.