I used to hunt a class mare that if I was approaching a wide hedge and ditch it used to lengthen its stride, its ears would get lower and further away as the stride tempo tempo altered not its speed. Alternatively if it was going to jump a five bar gate its stride would shorten and hocks came under it. Its ability to alter its action Im sure would not be restricted to jumping.
my thought process was along the lines that it had something more to do with why the hind toes are more pointed. To dig in, giving more traction, allowing the prey animal to accelerate quickly from a standstill. glad you enjoyed the vid.
Because "A" is longer than "B", there will always be some quantity of lift when that foot turns over...it is a physical impossibility for the foot to turn over without some of that motion directed vertically if the horse is on hard ground. If it is in soft ground, the mass will just push the toe down in the ground. However, like I stated before, I believe this 'lift' is more directed at forward motion than it is to actually moving the hip vertically with the ground because the is ahead of the placement of the foot and when turnover occurs the mass is well ahead of the foot...just like a sprinter in a starting block...if the horse were peg legged with the only two joints at the hip and DIP, you might see more of an elevation, but since there are several joints between the toe and the hip that flex and 'absorb' this vertical motion, I doubt it will ever be visible with a camera regardless of the speed.
We are both right and we agree in regards to the principles involved, though I think we view it from different perspectives. I wish Tom Stovall was here as I've engaged him in various permutations of this discussion on several occasions. As an expert on shoeing speed horses, Tom Stovall has a lot of empirical insight to offer on this topic especially in regards to what works for sprinters and runners on various surfaces and how the horses body reacts under acceleration vs top speed.
Hmm like the spokes on a wheel . . . rotating lever force turned into horizontal force . . . where have I seen that before? Scruggs, do you think there may be an optimal breakover point that might be found (theoretical) that would determine the length that lever should be?
No, I think all hopes of finding nirvana were lost when Cobain overdosed. Like everything else I think it depends on an incalculable number of factors including: deformability of substrate, fitness level of the horse, job of the horse, conformation, etc. In fact, I am almost of the opinion that the optimal length might change as the horse moves...ie. one length might be better for acceleration while another might be more efficient at the walk, yet another at full gallop, etc. In short, I ain't got a friggin' clue.
Stovall and I have discussed the idea of a self adjusting toe grab that would adjust based on load - sort of like a boat propeller that changes pitch based on the load on the blades . . .
I reviewing this excellent discussion between my betters, I see the factor of the substrate as the most influential in the mechanical variances in the way a horse performs. Hence the creation of the screw in stud industry.
