SPEED DEPENDENCY OF MOTION PATTERN CONSISTENCY

Treadmills are widely used in equine motion analysis. For the evaluati on of the trot of a horse, a trotting speed with low variation between motion cycles is necessary to make the measurements reproducible. The aim of this study is to show how an individual 'optimum' trotting spe ed for lameness quantification can be determined. In this study, the s tability of a horse's gait pattern was evaluated by calculating the st andard deviation (S.D.) of motion-cycle speed (MCS). In trot, eighteen horses were analysed at several speeds. The measurements were taken w ith the ExpertVision System (Motion Analysis Corporation) every 3 km h (-1) (= 0.83 m s(-1)), from the lowest to the highest individual trott ing speed. At the different speeds the S.D. of MCS and the asymmetry o f the vertical head motion were compared. At the speed where standard deviation was minimum, motion asymmetry was maximum. In twelve horses this optimum speed was situated in the middle of the individual trotti ng speed range, and in six horses the optimum speed was the maximum sp eed. The method presented in this study allows the determination of an optimum trotting speed and so contributes to precision and consistenc y of equine lameness analysis. (C) 1998 Elsevier Science Ltd. All righ ts reserved.