Lameness of racehorses is assessed at an early stage using 3 MT9s along the spine of the horse. At the trotting track of Cabourg (Normandy, France, see photograph) researchers affiliated with the Cirale measure the symmetry of the back of a trotter. Small differences in movement of the right diagonal stroke versus the left diagonal stroke are caused by small tendon lesions. Using a simple measurement that takes less than half an hour, information is obtained that can otherwise only be made visible by x-ray or an elaborate camera system (Audigié et al 2002, J. Biomech).
The amplitude of the different positions of the back of the horse is calculated by double integration of high-pass filtered acceleration. The results are then averaged per step. Within only a few hundred meters of trot, sufficient accuracy is obtained to notice deviations of only a few mm (Pfau et al 2005, J. Exp. Biol.).
Photos copyright, 2005
Cirale, Dozule, France