.
The math is right!
The paradigm should be discussed.
The linked text, written by Mark Caldwell (link in the comments) presents some mathematics around the horse’s foot based on underlying assumptions that I don’t share, and I’ll try to explain the difference between our perspectives as well as the conclusion.
Let’s see:
The author sort of anthropomorphizes the mechanics and, by saying that forces “try to” do something, seems to attribute intention to ground reaction forces that he does not attribute to the horse. The horse, by contrast, is described as being in a defensive mode: it has to resist forces and prevent torsion.
The physics of ground reaction forces is written into their name. They describe the REACTION of the ground to forces that something or someone has applied to it beforehand.
To anthropomorphize the horse’s perspective in the same way, one could say: In our case, the horse is the one applying the forces. As horses are highly specialized in adapting to almost any surface, it should be expected that the horse intentionally asks the ground for a certain reaction. Any ground. And that it has the ability to prepare for almost any answer before it asks the question.
In my view, the horse is not a supposedly failure-prone system trying to defend itself against the attacks of ground reaction forces.
That does not mean that Caldwell’s calculations are mathematically wrong. If, at a given moment, a resultant ground reaction force acts at a certain distance from the instantaneous centre of rotation of a joint, an external joint moment can be calculated from it. But the causal story he tells from this is much stronger than the calculation itself.
To break the “yes – no – yes, it is – but” cycle in the discussion between the model of muscle-driven levers and that of a prestressed, self-organizing system, what we would need now is a mathematician or physicist who could provide a mathematical model of a living, anticipatorily controlled, prestressed movement system:
How much would the calculated force pathways, local tendon forces and joint moments change if the same limb were modelled not as a series of levers, but as a prestressed, coupled, deformable network?
The equine finite element models that offer such possibilities do treat tendons and ligaments as tension-bearing structures, but to my knowledge they do not yet consistently model the entire limb as a continuously prestressed network whose global distribution of tension reorganizes with every change in posture. And yet, for example, they arrive at the conclusion that a steeper palmar angle increases loading of the lamellar layer rather than reducing it, as might have been expected (link in the comments).
The question, then, is how appropriate torque calculations still are as a model today, particularly in the context of hoof care.
I agree with the conclusions drawn from calculations such as the one described to the extent that a reasonably symmetrical hoof probably provides the horse with the best conditions for successful interaction with the ground.
There is, however, another interesting aspect to the interpretation of mathematical calculations: If a farrier or hoof-care practitioner claims that only one particular hoof geometry enables a horse to function correctly, because there is only one correct result to the mathematical equation, they implicitly assume responsibility for the entire locomotor outcome — as a structural consequence of the assumptions underlying their model.
If, instead, we see the task of hoof care as leaving the horse with a sufficiently large, pain-free and functional solution space, then the horse’s actual development depends on how it is kept, trained and ridden, and on the movement patterns it establishes.
https://www.facebook.com/share/p/1MfEiWzuSW/
https://beva.onlinelibrary.wiley.com/doi/10.1111/j.2042-3306.2010.00319.x
https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2026.1767386/full
