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10.5.2022: The Ridden Horse Pain Ethogram – Research and Development

Does Your Horse Lean In On The Turn?

This small study looked at how much horses leant in on the circle, both in hand and ridden, in trot and canter. The researchers found no differences between the amount of lean to the left compared to the right, which suggests that leaning in more on one rein than the other could be a sign of a problem. They discovered that younger horses tended to lean in more than older horses, and horses who performed better in their ridden work leaned in less than horses who performed less well. This seems sensible, since a better balanced horse will generally score higher in his ridden work, and I would expect young horses to be less balanced in their way of going.

Greve, Line & Dyson, Sue. (2016). Body lean angle in sound dressage horses in-hand, on the lunge and ridden. The Veterinary Journal. 217. 10.1016/j.tvjl.2016.06.004

You can access this article here.


Animals can minimise the risk of falling by leaning into a curve. Horses ≤ 6 years of age leant more than predicted compared with horses ≥7 years of age. Ridden work-quality grade was significantly associated with leaning. There were no differences in lean between trot and canter, on the lunge or ridden. There were no differences in leaning between left and right reins.


Animals can minimise the risk of falling by leaning into a curve. The aims of this study were: (1) to quantify the difference between observed (measured by an inertial measurement unit, IMU) and predicted body lean angle (calculated as a cyclist when turning) in horses; and (2) to compare circles versus straight lines ridden versus in-hand and trot with canter, and investigate the influence of age, rein and ridden work quality in trot (Fédération Equestre Internationale grading scale 1-10) in horses. Thirteen non-lame horses were assessed prospectively in a non-random, cross-sectional survey. The horses were trotted in straight lines, lunged and ridden on both reins. A global positioning system-aided IMU attached to the skin over the tuber sacrale quantified body lean and recorded the velocity and the radius, which were used to calculate predicted lean. Horses ≤ 6 years of age leant more than predicted (mean ± standard deviation 2.9 ± 2.6°) and more than horses ≥ 7 years’ old (0.4 ± 3°) (P = 0.01). Horses that scored ≥ 7 in ridden work quality leant less than predicted (-1.1 ± 2.7°) and less than horses which scored ≤ 6 in ridden work quality (2.4 ± 1.5°) (P = 0.02). There were no significant differences between trot and canter, either on the lunge or ridden (P = 0.3), or between left and right reins (P = 0.2). Asymmetry of body lean between reins may be abnormal and may be helpful for recognition of lameness.

Dr Sue Dyson and I are in the process of writing a book for horse owners and riders on how to understand and use the Ridden Horse Pain Ethogram with your own horse. The book will be published by J A Allen, and available sometime In 2023. Sign up to my newsletter at for updates.

In the meantime, you will find my blog on how to use the RHpE with your own horse here. You can learn more about the Ridden Horse Pain Ethogram through listening to Dr Sue Dyson explaining here it on the Equine Veterinary Education, where you can also listen to her discussing many of the other studies that she has been involved in. You can also take an online course with Equitopia.

© Sue Palmer, The Horse Physio 2021

Treating your horse with care, connection, curiosity and compassion

May 10, 2022
Sue Palmer