Abstract
Periodical changes in movements of both horses and riders were analyzed as rhythms on 5 Thoroughbred horses (TH1 to 5), 3 Hokkaido native horses (HH1 to 3), and 3 riders on TH1 and HH1 in walking and trotting on a treadmill from still pictures of video taped records (VTR). Rhythms of vertical and forward-backward movements of the markers attached to the horses and riders were obtained from sequential still pictures of VTR. By means of Fast Fourier Transform (FFT), the rhythms of movements in the horse and the rider were characterized by 2 indices, the frequency and amplitude. On the horse without a rider, the vertical amplitude (V-Amp) was greater in caudal parts than cranial parts of the trunk. The forward-backward amplitude (FB-Amp) was significantly greater in caudal parts than cranial pars at a walk both in TH (P<0.01) and in HH (P<0.05), and it was greater in cranial parts than caudal parts at a trot in both breeds (P<0.01). The movement rhythm of the rider on HH was characterized by higher frequency and smaller amplitude than that on TH. The stride length of HH with a rider was smaller than that without a rider.
