Rider Weight and Pressure Under the Saddle

A study was conducted in 2019 to establish pressure differences under saddle with riders of various weights and sizes.

In the saddle fitting world we are often faced with large or tall riders with short backed horses and so it is important for us to understand the effects of squeezing a rider into a saddle.

The study looked at a small selection of horses (6) and (4) riders of various size and weight.

Each rider was put into a wight category of Light, Moderate, Heavy and Very Heavy. It is worth noting that the riders body composition was not measured or referred to in this study.

Key Findings

Rider Positon

Both the Heavy and Very Heavy riders were consistently out of the desired shoulder, hip, heel alignment and both were forced to the rear of the saddle often with their lower leg further forward.

Average Pressure

As is to be expected the lighter rider exerted significantly less pressure overall whereas the very heavy rider exerted significantly higher pressure overall. The Moderate and Heavy rider exerted similar amounts of pressure.

Pressure per Area

In all gaits the Very Heavy rider caused more pressure under the rear of the saddle whereas the Light, Moderate and Heavy rider created more pressure towards the front of the saddle.

Conclusion

In simple terms if the rider is too big for the saddle they will be forced to sit further back and create more pressure under the rear part of the saddle (towards the horses lumbar region). The study concludes that despite the Heavy rider sitting on the cantle of the saddle the pressure distribution was more even than the Very Heavy Rider. Rider body composition plays a part here and should be consider in future studies in my humble opinion.

Excessive pressure towards the rear of the saddle can cause pain for the horse as well as gait abnormalities.

This study does have it's limitations, there was a small study group and limited data collected however it does prove a pretty obvious hypothesis: 'heavier rider equals more pressure'.

The main concern is with the pressure distribution and overly loading the rear of the saddle area. We know this can cause issues for the horse so how do we prevent this?

In short the saddle must fit the rider to prevent damage to the horse.

The horse only has a limited amount of space on his or her back and therefore saddle length and seat size will be determined by the horse. More research is needed into the implications of fitting beyond the horses last rib (T18) but assuming we want to stay in the 'safe zone' of the Thoracic spine there is only one answer which is to ride horses who have sufficient back length for the riders size. If owners choose to ride horses that are not capable of taking a large enough saddle; the owner must accept that they may be damaging the horse.

While saddle fitters can make alterations to the saddle i.e. overshoot the seat, shorten the panel, there is a limit to what can be physically achieved and the horse will inevitably end up paying the price for our desire to squeeze onto them.

A link to the original study can be found here: https://beva.onlinelibrary.wiley.com/doi/10.1111/eve.13102

The effects of rider size and saddle fit for horse and rider on forces and pressure distribution under saddles: A pilot study

L. Roost, A. D. Ellis, C. Morris, A. Bondi, E. A. Gandy, P. Harris, S. Dyson