E. YOSHIHARA*, T. TAKAHASHI, N. OTSUKA†, T. ISAYAMA, T. TOMIYAMA‡, A. HIRAGA and S. WADA
Equine Research Institute, Japan Racing Association, Tokami-cho, Utsunomiya, Tochigi, Japan; †Ritto Training Center, Japan Racing
Association, Misono, Ritto, Shiga, Japan; and ‡Education Center, Japan Farriers Association, Tsuruta, Utsunomiya, Tochigi, Japan.

Summary
Reasons for performing study: It has been suggested that the
heel of the horse’s hoof expands in the stance phase and this
reduces the concussion at impact and helps pump blood into
the hoof. Therefore, farriers usually leave a gap in the heel
region when using the traditional nailed shoe. Recently glued
shoes which are attached firmly to the heel have been
developed and these could restrict heel movement.
Objective: To compare the degree of mediolateral heel
movement between glued and nailed shoes.
Methods: Seven Thoroughbreds were used. Either their fore- or
hind hooves were shod with plain aluminium shoes, attached
first with glue and later with nails. Measurements were
collected continuously with a displacement sensor fixed
between the medial and lateral hoof walls at the heel. The
horses ran on a treadmill at a walk (1.8 m/s), trot (3.5 m/s),
canter (8 m/s) and gallop (12 m/s). The mediolateral heel
movement in a nonweightbearing position was set at zero for
each hoof and thus positive and negative numbers represented
expansion and contraction, respectively. Average values of 10
consecutive strides at each speed were compared between the 2
shoeing methods by paired t test.
Results: At all running speeds, the heels expanded in the first
70–80% of the stance phase and contracted at breakover. The
total heel movement calculated as the sum of the maximum
expansion and contraction value was less with glued shoeing
than with nailed shoeing for walking (all limbs), trotting (all
limbs), cantering (leading forelimb and both hindlimbs) and
galloping (both hindlimbs).
Conclusions: Glueing restricted heel movement, suggesting
possible interference with shock absorption and blood
pumping in the hoof. Further study is needed to evaluate the
influence of glued shoeing on hoof mechanics.

I love this study, and the data tells a much bigger story than nails vs direct glue. For example, would anyone have been willing to bet that a front hoof contracts more than in expands at the walk? I find that to be fascinating. All of the Internet arguments about how shoes cause contracted hooves, and as it turns out certain shoes prevent the hoof from contracting.

If you don't mind my asking when was the study performed?

I wonder how the results would differ if a modern polymer shoe were used and how a quixshoe would alter results. I think it would also be interesting to have a barefoot horse as a control for this study but, I don't remember barefoot horses being very popular when I lived in Japan. So, it makes sense they wouldn't have thought of using one as a control.

Very interesting study. Is it possible to see more of the data/ meta data from this study?

Thanks for posting
David

It was published in 2010 in the Equine Veterinary Journal. I also wondered about barefeet, and different types of shoes (Sigafoos). The data collection occurs on a treadmill, and some places will not put barefoot horses on treadmills at high speeds. Treadmills can get pretty hot, and that might be an issue for some types of horseshoes.

Pat, precisely where was the measurement done i.e. something "like at the hairline, 2cm dorsal to the end of the heel bulbs" or some such desc. Nearly a cm of expansion at the higher speeds is a bunch.

reillyshoe wrote:
I talked to Ralph Casey about horse treadmills a couple years ago and he was of the opinion that aluminum shoes have no place on treadmills either. I didn't see it but he said he has data showing that aluminum shoes heat faster and hold heat longer than steel shoes. He felt that aluminum shoes had potential to cause harm to a horse if they were used on treadmills.

David

Jack Evers wrote:
I do think it's interesting that the foot seems to expand much more than it contracts and I wonder if the results would be different if the measuring device were moved closer to the ground surface?

I can't remember who it was but someone pointed out to me that the expansion/contraction marks left in the heel area of a worn shoe tend to indicate more contraction than expansion; based on where the foot contacts the shoe surface when unloaded.

David

DavidinGA wrote:
Using a baldor grinder with a 10 inch expander wheel on an aluminum shoe will quickly reveal the data.

This is really interesting, thanks Pat.

It struck me that a non weightbearing situation is the zero displacement line. Where the walk displacement when landing and loading is not really surprising, the negative displacement when breakover/heellift is likely to occur is. In fact the graphs show that when a foot is picked up on a standing horse the heels are wider compared to the width of the heels during break over. (If I interpret the graph correctly that is.....)

It must be DDFT pull during breakover that contracts the heels -at least at the footside of the shoe- and pulls them in resulting in a more narrow heel than that same foot has when its non weight bearing

When discussing breakover I always felt that "primary movement" of the hoofcapsule does not exist in a healthy horse. It is always the coffin bone that initiates break over (well, the brain/muscle and what have you....) and the hoofcapsule following when and as long as the lamellair bonds allows that.

Considering the real tight space between bone and hoofwall it seems obvious that regular crushing as in jamming of bloodvessels in the equine foot is a normal occurence given some elasticity of the lamellar bond. Thinking of complications in laminitic horses I can now understand a little easier why constriction of bloodflow in a bowel causes necrotic tissue in a real short period of time (hours or less), but in a foot constriction of bloodflow leads to necrosis only when the duration of that constriction is way longer (days or longer).

You got to love this job!



Ronald Aalders

Contraction of the heels in the breakover phase ,is very interesting ,could this also have any connection to the contraction in laminitic cases where the heels seem to grow fast and the hoof narrow ,even with an increased heel first landing ???

And upright clubby contracted feet with atrophied frogs! that dang ole ddft. I feel in both clubs and chronic laminitis the tendon "sling" load due to tendon pull is greater than downward ram load through the bones into the heels. This prevents p3 from pushing into hoof capsule and expanding heels. The reason I believe that when you add tendon relief ie wedging or rocker shoe this allows more downward ram load and pushing into hoof capsule at the heels and not directed towards apex of frog.
What do ya think?

There are a lot of "if"s and "maybe"s in that statement.

I think one interesting observation is that heel expansion appears to be dependent on gait (more speed=more expansion). This does not appear to be true for heel contraction. The change at the walk and at the trot and at the gallop are pretty consistent. If the contacting was caused by the pull of the DDFT, wouldn't you expect this to change at different gaits?

Ronald Aalders;235740 wrote:

Me sure likes Pat's threads!!!me brain hurts now ...better get some more trims done !!

ray tyron wrote:Considering the attachment(s) of the DFT, mechanically, how would that be possible? Theoretically, would the expansion/contraction have more to do with blood volume pressure(s) within the hoof capsule, ie: the fact that the liquid is incompressible and thus as volume increases something has to change(soft tissue expansion) to accomodate the increase in incompressible liquid in a confined space(the hoof capsule)?

Since the glue encompassed/extended the full length of the wall. comparitively speaking, where were the last nails located when the shoes were nailed on? Also, regarding the concern about heat build up on the treadmill, have any studies been conducted to determine just how much heat build up there would be over any given period of time and how that compares to, for instance, the heat build up in the hooves of horses who work in desert footing conditions? More basically, have any studies been done to determine the [relative] maximum amount of heat a hoof can tolerate before 'failure' occurs and damage is done? (I realize that this is somewhat off topic but the question/issue has arisen and, I think, deserves some consideration as a component of the referenced study and others).

All in all, a thought provoking study. Thanks for postng it Pat.