The tell-tale sign of repeating untruths is when a person says "I trained and raced horses for 40 years". The accepted beliefs from the past are almost always wrong.
Here is an example " because of the direction in which we race and the pulling motion on their right side in the turns. That is why i have found across the board pacers almost always bow in the right front." The root is this fallacy is the belief that the outside limbs take a disproportionate load in the turns. It's likely that the belief stems from 4 wheel autos where we all know the outside tires take almost all the stress in the turns. Not so for horses.. in a turn the inside legs migrate towards the centre line and the outside legs aren't much more than outriggers for a brief duration. The most compelling studies on inner versus outer injuries come from Australia where the incidence of splint bone displacement was tracked and quantified.
Of course fatigue on the inside prompts extra load on the outside so the chicken and the egg conundrum will always be present.
Is this the study you're referring to:
https://www.frontiersin.org/articles/10.3389/fvets.2021.698298/full
