Effects of a girth, a saddle and weigh on the movements of the horse

Back-pain is one of the most common and least understood clinical problems in horses. As an important cause or aggravator of back-pain, poorly fitting saddles are often mentioned. This study was initiated to determine the effects of various forms of tack on the movements of the horse, under loaded and unloaded conditions. Data were captured during treadmill locomotion at walk, trot and canter under four conditions: unloaded, a lunging-girth, a saddle only, and a saddle with 75 kg of weight. The back movements were quantified by maximal extension and flexion angles and by the total range of motion of vertebrae L3 and L5. Limb movement was quantified in terms of maximal pro- and retraction angles. Data were statistically analysed in an ANOVA repeated measurement test followed by a post hoc Bonferroni test. The overall extension of the back was increased, and maximal flexion angles were decreased, by a saddle with weight at all gaits. At walk the retraction angle of the forelimb increased. At trot this increase was accompanied by increases in retraction angles of the hindlimbs and in the protraction angle of the forelimbs. At canter a smaller decrease in the maximal flexion angles was observed in the saddle only situation, but there was no influence on pro- and retraction angles. Weight and a saddle induce an overall extension of the back. This may contribute to soft tissue injuries and the kissing spine syndrome. The changes in limb movement are considered a compensatory mechanism for the changed back-position.