The Horse Physio - Delivering care with expertise since 1992

The rider size debate and the welfare of ridden horses

A Guest Blog from Sue Dyson

In the 2023 British Dressage Members’ Handbook it is stated:

‘British Dressage is committed to upholding the highest standards of welfare, health, and well-being for both horse and rider, and a central tenet of this is promoting a harmonious partnership. To achieve this, the rider should be the correct size for their horse and suitably mounted. The horse and rider partnership must be in balance, and the rider should not exert undue influence on or restrict the horse’s natural way of going.

The rider should be proportionate to their horse, with the core stability, suppleness, and fitness necessary to achieve a harmonious way of going. When considering the carrying capacity of an equine (they mean a horse; equine is an adjective commonly misused as a noun), the height and size of the rider, along with the age, type, fitness, and body condition score of the horse should all be taken into account.

As a general guideline, it is recommended that the maximum load of an equine (a horse), including tack and equipment, should not exceed 20% of the horse’s total body weight, based on a horse with a ‘good’ condition score. It is the members’ responsibility to ensure that they respect these guidelines, in the interests of equine welfare.

The purpose of this guidance is to ensure that a member’s way of riding is effective and sympathetic to their horse, and not a measure to prevent their participation.’

At face value, this all sounds like common sense and considers both rider and horse factors. The aim of dressage is to promote and epitomise harmonious horsemanship. However, the adage that ‘the proof of the pudding is in the eating’ could not be more true. Let’s consider rider size – which has to consider not just weight and height but also morphology (shape), for example, trunk length versus leg length, the size of the rider’s buttocks, and how weight is distributed over the body of the rider. For there to be appropriate weight distribution on a horse’s back via the saddle the rider should be sitting in the central third of the saddle, as close as possible to the horse’s centre of gravity. The ability to do this is influenced by the shape and length of the seat of the saddle, the height of the cantle of the saddle, the position of the stirrup bars, the size and shape of the saddle flaps and the position and the size and position of knee rolls and thigh blocks.

If a tall rider has a long upper body but their leg length is readily accommodated by a saddle so that they can sit in the centre of the saddle it is not a problem (assuming that the rider has appropriate skill, balance, coordination and core stability and sits straight, not crookedly!). However, if a rider of identical height had a proportionally much longer leg length it may be more challenging to find a saddle that both fits the horse and enables the rider to sit in the middle one-third of the seat of the saddle. This is particularly a potential problem for teenage riders on ponies.

It is immediately clear that larger riders have to work closely with a saddle fitter who understands the importance of saddle fit not only to the horse, but also to the rider. Why is this so important? We know that the thoracic dimensions of a horse (the region under the saddle) increase during a work period of 30 minutes, assuming that the horse is working correctly in a well-fitted saddle. This expansion is important for correct muscle function and, over time, for correct muscle development in a young horse. With heavier weights or load distribution concentrated over the caudal third of the saddle, the thoracic dimensions may remain static or even decrease during the exercise period, with long-term adverse consequences for both muscle function and development. If a saddle is too small for a rider the force per unit area under the saddle is higher than for a larger saddle.

Force = mass (weight) X acceleration. Forces under the saddle therefore increase with greater speed and will be higher in canter than in trot, especially with a rider in a conventional ‘three-point’ position, rather than ‘sitting-light’ in a two-point position. With larger riders the percentage of time that each limb is bearing weight during each stride increases, effectively sharing load between limbs. The load transmitted through each limb is proportionally higher as the weight of a rider increases.

The rider is filling the saddle, however, the horse’s thoracolumbar length could accommodate a longer saddle which would reduce force per unit area under the saddle. The horse is in canter, which lacks a suspension phase, and is on the forehand.

When talking about the weight of a rider plus equipment not exceeding 20% of the horse’s bodyweight, of a horse in ‘good’ body condition score what do we actually mean? The weight of a conventional saddle and bridle is approximately 12 Kg. An average Warmblood dressage horse is approximately 600 Kg, so 20% is 120 Kg. That means the weight of the rider, plus clothes, boots and helmet should not exceed 102 kg. However, we have to bear in mind that there is an epidemic of obesity amongst horses, especially show horses and dressage horses, and many are not in ‘good’ body condition score (≤7/9), but are overweight. This means that the horse itself is carrying excessive weight, with a variety of deleterious medical consequences such as laminitis. So, in reality, a dressage horse of 600 Kg may ideally be only 550 Kg, therefore according to the guidelines, the clothed rider with boots and helmet should not exceed 98 Kg.

There are many riders of 98 Kg. Recent figures showed that the average weights for males and females in England were 85.4 Kg and 72.1 Kg respectively. The Health Survey for England 2021 estimated that 25.9% of adults in England are obese and a further 37.9% are overweight but not obese. Frightening figures!

However, when overall horse welfare is concerned where does rider size fit? A relatively smaller, lighter rider who sits crookedly, is unable to ride in balance and in synchrony with a horse’s movement, is inadequately fit and has unstable hands and restricts a horse’s movement may have far greater deleterious long-term consequences than a larger rider whose weight distribution is ideal and who rides a horse forward. However, a larger rider may magnify the effects of a saddle which does not fit the horse ideally (a common scenario). Moreover, modern dressage horses have shorter thoracolumbar regions than their predecessors, so being able to fit a saddle which accommodates the size of a large rider may be challenging.

A large rider is sitting on the caudal third of the saddle and her thigh is too large for the saddle flap. The horse’s thoracolumbar length would not accommodate a longer saddle. This is not a picture of harmonious horsemanship. The horse is also overweight.

There are no straightforward answers to these conundrums. Raising awareness of a rider’s responsibilities for the welfare of their horse must be applauded. The guidelines issued by British Dressage are an important step forward. How many riders think of themselves as athletes, consider their need to be fit, think about their own position and perhaps perform specific exercises off a horse to improve their flexibility, core stability and balance? How many coaches give constructive advice about improving rider skill rather than focussing on a horse’s way of going? How many riders think that it might be money well spent to have a few sessions on a mechanical horse focussing on their position?

Going back to the guidelines from British Dressage, ‘The horse and rider partnership must be in balance, and the rider should not exert undue influence on or restrict the horse’s natural way of going.’ This indirectly raises yet another vitally important fundamental issue which I have debated previously, restricting a horse’s movement by working with the horse’s head behind a vertical position. We need to continue to strive to eliminate this practice.

All riders must take ownership of their responsibilities for their horse’s welfare. None of us wants to do a horse harm, but through lack of awareness, we sometimes do so. Food for thought.

Copyright Sue Dyson 2023

Sue Palmer, aka The Horse Physio, is an award-winning ACPAT and RAMP registered Chartered Physiotherapist, an Intelligent Horsemanship Recommended Trainer, and holds an MSc. Formerly a competitive rider and BHSAI, she works full-time treating horses. Through multiple books and articles, Sue shares with you her passion for ethical and harmonious horsemanship.

Photo of Sue Palmer and Belvedere

Sue Palmer and Belvedere

Sue says “Keep an eye out for my next book, “Harmonious Horsemanship: How to use the Ridden Horse Ethogram to Optimise Potential, Partnership, and Performance”. This ground-breaking book is co-authored with Dr Sue Dyson, and will be available summer 2023. Sign up at to be kept up to date with new information as it comes available. In the meantime, you can find out more about the Ridden Horse Ethogram here.”

Other books by Sue Palmer M.Sc. MCSP:

‘Horse Massage for Horse Owners’

‘Understanding Horse Performance: Brain, Pain or Training?’

Cover of 'Horse Massage for Horse Owners' by Sue Palmer

Horse Massage for Horse Owners, by Sue Palmer

Cover of 'Understanding Horse Performance: Brain, Pain or Training?' by Sue Palmer

‘Understanding Horse Performance: Brain, Pain or Training?’ by Sue Palmer

Photo of Sue Dyson and Sue Palmer, co-authors of 'Harmonious Horsemanship'

Sue Dyson and Sue Palmer, co-authors of ‘Harmonious Horsemanship’