Kinematics of the horse’s back during rising trot
19 Aug 2016
Scientists in France set out to use IMUs to measure horse’s back movements while being ridden. An IMU (Inertial Measurement Unit) is an electronic device that measures forces and angles, using a combination of accelerometers and gyroscopes. This was the was the first study to place IMUs on horses being ridden under saddle.
A mat under the saddle was also used, which recorded pressure and a gauge in the stirrups measured stirrup force. The horses and test rider wore reflective markers throughout the study and were videoed, which enabled the researchers to calculate their respective centers of mass (COM).
To conduct this study, three horses of approximately the same build were used. They were all ridden by an experienced rider using the same saddle. The saddle was fitted by an accredited saddle fitter.
The results of the study showed that during the sitting stance, the horse had a greater range of motion through the T6-T12 and L2-L5 areas of the back and less range of motion through the T12-T16-L2 section. During the rising stance, the horses had a greater range of motion through the T12-T16-L2 parts on the back and less range of motion though the T6-T12 and L2-L5 areas of the spine.
The researchers noticed that the pressure mat indicated less pressure from the rider than their calculations assumed. They hypothesised that this is because a good rider is able to control some of the amount of pressure he/she puts on the horse’s back by using their knees as shock absorbers.
A further finding of the study was that during the rising stance, the weight was more over the front and middle of the saddle, whereas during the sitting stance, the weight was mainly over the middle and back of the saddle and distributed also over a greater area.
In summary, this study helps give further insight into how a horse’s range of motion is affected by rider position at the rising trot.
Martin, Pauline, et al. Effect of the rider position during rising trot on the horse׳ s biomechanics (back and trunk kinematics and pressure under the saddle). Journal of biomechanics 49.7 (2016): 1027-1033.