tbloomer wrote:
scruggs1 wrote:
OK...so with all the trigonometric jargon aside, we seem to be in agreement that the tension in the DFT is a, if not the, determining factor in both the direction and subsequent structural integrity of the horn at the heel...a taut DFT encourages a more perpendicular orientation of the heel horn and a lax DFT encourages a more horizontal orientation of the same.

I will assume an agreement that a more perpendicular orientation of the horn has a greater load bearing capacity where a more horizontal orientation has a diminished load bearing capacity. (should that be an incorrect assumption feel free to correct it)

Now the continuance...

tbloomer wrote:
Are levers and fulcrums in the leg in and of themselves contributing factors for heel horn failure?

tbloomer wrote:
Are these tissues more directly effected by pressure or by location of overlying levers and fulcrums?

tbloomer wrote:
Do the locations of any of those in the leg change when an unshod foot gets a shoe nailed/glued to it? (Ie., you have a horse standing on concrete, next, you nail shoes to all 4 feet. Does the spatial orientations of any of the fulcrums and levers in the leg change at all?)

tbloomer wrote:
http://www.youtube.com/watch?v=xz-pzg-b7DI


What is the purpose of adding length to the shoe?

In your understandable but not that easily answered questions you forgot to add the landing and loading part.

Shoeing does not only affect breakover and support, through this it also affects landing and loading. The way a foot lands and loads will for sure change the angle of horn tubules in the heel.


Ronald Aalders

John, it's a good question. I wish I had time to be more specific, but I'm up to my eye***** in horses until I leave for the Tevis next week. (13 TODAY, not all with shoes) Short answer - if the shoe has enough structural strength to serve as a loosely supported cantilever beam (support from weak heel horn or about 5/16 th inch of steel), excess length is support taking some stress off the DDF. If it does not have this structural strength -a race plate or a worn out shoe- that extra length is leverage to help collapse the heels.

scruggs1 wrote:I asked where the fulcrum(s) in the foot were located in regards to the interface between the horse's weight and the ground. You are asking about stuff in the leg.

Let's start at the bottom and work our way up without skipping the hoof capsule and the coffin bone. Can we discuss the hoof capsule and the coffin bone as a discreet levers unto themselves and isolate them for the purpose of discussion?

It's called "segments" of the distal limb of the Thoracic or Plevic limb(s) within the Locomotor System of the horse:rolleyes:

Socrates would be disappointed but I am going to take a break from the questions and try to steer this discussion in a better direction by making some points...well, points as I see them...as to how length is leverage on some feet.

1. Force plate studies have shown that appliances that elevate the heel increase the load/pressure on the heels...I'll go see if I can find a few abstracts to post tomorrow, but some are already on here.
2. Tighter flexors allow more length accumulation before failure and facilitate a more vertical orientation of heel horn from the coronary. More lax flexors allow less length accumulation before failure and facilitate a more horizontal orientation of heel horn from the coronary.
3. In soft footing, adding palmar/plantar length (or a bar) to the shoe has the effect of elevating the heel (which has already been shown to increase pressure on the heels). In addition, raising the heel reduces tension on the DFT which also is a contributing factor in heel horn failure.

One of the problems I had was seeing "the foot" or "the leg" as entities and trying to approach them as such. Many hours of thinking about, reading about, and experimenting with the high/low horse, and other flexural deformities helped lead me to a better understanding. There is a broad range of tensions from the very tight to the very lax and we manipulate them every time we trim a foot. Often times, to get the phalanges in alignment (which is generally considered to be one of the canons of farriery) we are focusing on one aspect of the leg (orientation of P1-P3) and doing a disservice to the remainder of the leg (flexors). Yes, we can "support" the leg, whether it be ill-aligned phalanges, a DFT that actually needs relief, a navicular issue, etc. by sticking shoe out the back of the foot. However, by aiding one aspect of the leg we are sometimes compromising another (in many more instances than just the heels that I am talking about here).

The heels, on that pitiful foot that someone gave Travis to shoe on the other thread, looked compromised already. Someone made the comment that he should have stuck more shoe out the back...I think from the standpoint of helping the heels, he did a beautiful, functional, safe job on that foot and did the heels justice by not sticking extra length out the back...but that is my opinion and I won't bother debating it...I like it, others may not, and that is okay too.

Anyway, in my opinion, when we encounter a compromised heel, the way to address it is to remove the structural load on it...transfer that load somewhere else (to the frog with a heart bar, to the rest of the foot with a pour in or DIM, etc.) and if a flexor needs help, or some other system in the leg will benefit from flexing the DIP, then a wedge, bar shoe, or a bunch of length can be stuck out the back, but the heels need to be unloaded or the load bearing burden transferred elsewhere. To successfully address multiple issues (as in the failed heel, misaligned phalanges on the low foot of the high/low horse) we have to modify our thought process (or at least I did) and realize that there are two (or more) different problems in that foot and each needs to be addressed as separate system.

Just sticking extra shoe length out the back of a foot is counterproductive for "supporting" a failing heel as it adds more load to the already overloaded horn. An upright heel that has good tubular integrity can handle more load, so more shoe can be stuck out, wedges used, bar shoes, etc. but the low foot does not have a high load bearing capacity in the heels (when compared to the upright) so I don't see the benefit of adding to its load when it is already failing at accepting its current load.

There are many complex systems in the leg that each must bear their own burden. In our best efforts to "help" the horse, many times "easing" the load on one system simply overloads another.

John, do you feel the heels of the foot in question are the way they are because of horn quality, or do you think they may be a product of a weak digital cushion.(I know it's hard to tell from a picture)

IME a foot with the characteristics shown are suffering from a lack of internal structures and must be maintained with some form of a false digital cushion. I have had good luck with a bar shoe and some form of frog psi, although I think it will continue to be more of a maintenance issue than a fixing issue.

scruggs1 wrote:
Well said John, thanks.

A theory was expressed to me some time ago by 5 different scientists from 3 different disciplines. Each having tested and confirmed it for themselves in their own experiments.

Not wanting to accept their conclusions, I came here to test it for my self.

Thus concludes my research and confirms their hypothesis.

Thank you for participating.

Baron, thank you for providing the laboratory.

Wow this virtual reality stuff is amazing!

scruggs1 wrote:
I WILL ,Again flawed assumptions, it is dependent on direction of force as well as dissipation of force , your assuming the force is one of only horizontal & one directional & stagnant , you have also omitted angles that give strength & resistance during geometrics in relationship to motion & ground surfaces , you have also left out angles being required in aiding proper expansion which can & does fluctuate between different hoof types & limb conformations .

There are many complex systems in the leg that each must bear their own burden. In our best efforts to "help" the horse, many times "easing" the load on one system simply overloads another.

now your catching on

tbloomer wrote:


Hey did I give you permission to do any tests on me.

Tom your assuming Ducket's Dot is correct on all horses all of the time just like many have assumed the same with Ovnicek. I think the power of suggestion and your understanding of physics have made you delusional. I am surprised Tom Stoval has not stepped in and challenged you with dead Greek stuff.

In case you have not noticed a few of us can carry on a conversation about support or leverage. I figure this must be do to just shoeing horses for a living.

jack-mac wrote:

What I find very surprising on all theses methods & theory's put forward to date by the supposed guru's on the subject of crushed heels & bent tubules, circulation at the coronet never gets a looked at or brought up, its always about chopping the heels down low & leaving the heels of the shoe long to were no heel would ever be found or grow on any horse naturally & its always churched up in a nice sounding package & presented as giving the horse more support or its was a nasality to straitening tubules & all the numb sculls concur nod there heads agreeably. the fact of the matter is, its the balanced of pressure at the coronary & how circulation is distributed evenly to the areas of the coronet that effects heel quarters & toe growth, leaving a heel of a shoe to short or to long effects the out come of what area will receive the required amount of blood flow for healthy balanced growth rate , leaving the heel long on a shoe other then allowance for time factor of shoeing cycle, is nothing more then poor shoe fitting & detrimental to the heels, due to excessive pressure staving new horn growth of circulation.

jack-mac wrote:

That's what I was trying to point out in my last post, a lack of the internal structures of the foot functioning properly. The heels got that way from something else IMO, not poor horn/tubule quality.