LOW HEEL / HIGH HEEL SYNDROME - UNRECOGNIZED PROBLEMS & CONSIDERATIONS

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by Dr. Kerry J. Ridgway, DVM

Introduction:

The commonly observed condition where the heel of one front foot is higher
than the other has ramifications that extend well beyond the effects on the
foot itself. This condition is also observed in the hind feet though less
frequently. However, because of limitations and scope, this paper will
direct its attention primarily to high heel/low heel of the front feet.

How to best deal with the condition has remained a "hot topic" among
farriers and veterinarians for a very long time. It is the aim of this paper
to explore some of the biomechanics and often un-recognized ramifications
such as creating nearly impossible saddle fit, muscle imbalance, and changes
in posture. All of these can result in loss of performance and are a
potential source of lameness.

Many if not most of the veterinary and farrier professions are of a mind
that asymmetry is the normal state and is associated with brain
lateralization, creating a dominant side (referred to in the human as
handedness). It is felt that the heel/hoof capsule asymmetry is associated
with grazing patterns, perhaps genetically instilled and what you see is
what you get.

I think that, whatever the source, a case can be made that the limit of the
body's tolerance for asymmetry is not infrequently exceeded and this case
horses need all the help they can get. At least that is the situation if
they are to be ridden and even more so the situation if a high level of
performance is expected. There is a remarkable tolerance for asymmetry in
the body of most structures.

Our problem as veterinarians, farriers, and riders is where is that point
where asymmetric tolerance ceases and pathologic change and damage commence?
Why is it exceeded?

In a natural state, i. e. so called, "wild" horses, if they exceed the range
of functional asymmetry, they become part of the food chain. In our domestic
world, we breed any and everything and discard or cull nearly nothing. I
make this last statement without judgment. But by our management practices,
it is my contention that we put into the pool many horses whose asymmetries
go beyond the balance tolerance point and create pain, performance deficit,
subclinical lameness and eventually overt lameness.

The problem is compounded by inappropriate riding, inappropriate trimming,
inappropriate shoeing, inappropriate manipulation, inappropriate saddling
and inappropriate veterinary procedures. In my career as a veterinarian
specializing performance horse issues and subclinical lameness, muscle
tension, imbalances and symmetry since 1990, I deal daily with muscle
issues, saddle related problems, shoeing related problems and back pain.

These problems constitute as much as 90% of my practice. That has afforded
me ample opportunity to observe and evaluate the relationships of high heel,
low heel to pathologic consequences on a first hand basis.

Awareness of some of the problems came to me about many years ago via Moses
Gonzales, journeyman farrier. He demonstrated to me the effects that a low
heel/high heel syndrome had on the horse's posture. Farriers and
veterinarians, all too often, counter Gonzales's observations with
skepticism or antagonism. Healthy skepticism is always appropriate, so let
us try to examine the issues on their merits.

I believe that antagonism needs to be challenged and skepticism addressed.
At the very least, this subject needs to be revisited with an open mind.
Appropriate trimming and/or shoeing combined with appropriate body work and
riding remains the key to soundness.

Significant awareness has come from recognizing that the syndrome can
grossly alter the shape of the shoulder and the back. Altering the posture
and shape of the shoulder and wither area creates problems with saddle fit.
The resulting posture of the horse affects not only saddle placement but
also alters the rider's posture and balance and ultimately the rider's
soundness.

Postural deviation and effect on joint angles as a result of High Heel / Low
Heel:

Let us first discuss the overall postural deviations that are a direct
consequence of the lower of the two heels. It should be clarified, at this
point, that that it is not the intent to address a true "clubfoot."

This paper is also not addressing an anatomically "short leg" syndrome,
(though to a cursory evaluation, the limb with the lower heel may give the
appearance of a shorter leg). The low heeled limb is functionally shorter -
not likely to be anatomically shorter. A lower heel creates obvious changes
in the joint angles at the pastern, fetlock, elbow and scapulo-humeral joint
(shoulder joint).

Compared to the limb with the higher heel the angles on the low-heeled limb
will open (get larger), and the limb will become more vertical than its
counterpart throughout its length. The pastern joints and fetlock will be
placed in more extension (and possible subluxation). The elbow angle will be
more open.

As the scapulo / humeral joint (shoulder joint) opens, the "point" of the
shoulder will be moved caudally so its position is farther back than on the
higher heeled limb. The position of the scapula becomes altered so that it
rotates more vertical.

This verticality creates a bulging appearance to the shoulder and
over-development of the associated muscles on the lower heeled limb. This
asymmetry in the shoulder will cause the saddle to not sit straight on the
horse.

The pressure that a "crooked" saddle places on one side of the thoracic
spinous processes leads to pain and primary chiropractic issues on of the
upper thoracic vertebrae as well.

Observe that the horse usually has a marked tendency to lean on the shoulder
of the lower heeled limb. This may leave some observers to conclude that the
measurements that are to be described are "off" only because the horse is
leaning on that shoulder and that if one pushes the horse to an equal weight
bearing that the measurements tend to even up.

However, this point must be addressed and clarified. We must answer, why,
given a choice, does the horse choose to lean on that shoulder?

It is because of the difference in heel height that the horse returns to
leaning on the shoulder of the low-heeled side when allowed to do so. This
is the posture that the horse seeks as a compensatory posture.

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