Twenty dressage horses and their riders performed a pattern from which walk, trot and canter, and transitions from extended to collected trot were analyzed based on data from inertial measurement units that measured three-dimensional accelerations and rotations of the horse’s trunk, the rider’s pelvis and the rider’s trunk. The selected movements were observed on video and scored by two or three high ranking dressage judges. The judged scores were then compared with the data describing movements of the horse’s trunk, the rider’s pelvis and the rider’s trunk.