THE INFLUENCE OF THE RIDER ON THE TROTTING MOTION OF A HORSE

Abstract

Introduction: The characteristics of trot, such as collection, impulsion, action of the hind quarter, the position of the head and the balance of the horse are described in the Rules of Dressage Events of the Federation Equestre International. Up to now, these characteristics were judged subjectively by dressage judges, but no objective measures have been developed to substantiate these judgments. The aim of our study was to establish measurable criteria that make possible the quantification of dressage characteristics, by comparing the motion pattern of trotting horses ridden by two riders of different skill and being led on hand. Materials and Methods: Twenty horses aged 4 to 22 years at different training levels were measured being ridden at trot by a professional rider and a hobby rider, as well as being trotted on hand. The measurements were carried out from the right side, with six cameras (sample rate 120 Hz, resolution 240 x 833 points) tracing 20 reflecting spherical markers placed on the horse’s and rider’s right side. At least eight recordings of five seconds each were taken with the ExpertVision System of Motion Analysis Corporation with the horse trotting on a 12 m long pressed sand track in an indoor riding arena. At least eight motion cycles of each rider-horse combination and of the horses being trotted on hand were analyzed. The 3-dimensional movement of the markers was calculated, and the stridelength, speed, and vertical movement of the fetlock joints were compared. The data were normalized to the trotting speed. The normal distribution of each group was tested using the Kolmogorov- Smirnov test, and the Student test of paired samples was used to check the differences between the means of the groups of the above described parameters. Results and Discussion: With the hobby rider the horses had the significantly lowest trotting speeds, the smallest stride length, the highest head position, the smallest vertical movement of the fetlock joint and the longest duration of stancephase when compared to when the horse is ridden by the professional rider and trotted on hand. Between the horse’s motion when ridden by the professional rider and trotted on hand no significant differences could be detected in the trotting speed and the duration of stance-phase, whereas significant differences were established for head position and stride length. The vertical movement of the fetlock joint did not differ significantly when ridden by the hobby rider and trotted on the hand, but both did differ significantly from the vertical movement of the fetlock joint when ridden by the professional rider. The results of this study show that some terms used by the Federation Equestre International can be translated into measurable quantities, and thus a more objective judgment of dressage may evolve.