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Low Heel High Heel Syndrome

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Low Heel  High Heel Syndrome Powered By Docstoc
					Revised February 06




          Low Heel / High Heel Syndrome
                    Unrecognized Problems & Considerations

                               Kerry J. Ridgway DVM
                               Equine Therapeutic Options
                                 508 Coleman Bridge Rd
                                     Aiken SC, 29805
                                      803-643-9188
                              kerryridgwaydvm@yahoo.com



Introduction:                                  also alters the rider’s posture and
                                               balance and ultimately the rider’s
The commonly observed condition                soundness.
where the heel of one front foot is higher
than the other has ramifications that          Awareness of some of the problems
extend well beyond the effects on the          came to me about 15 years ago via
foot itself. This condition is also            Moses Gonzales, journeyman farrier,
observed in the hind feet though less          when he demonstrated to me the effects
frequently. However, because of                that a low heel/high heel syndrome had
limitations and scope, this paper will         on the horse’s posture. Farriers and
direct its attention primarily to high         veterinarians, all too often, counter
heel/low heel of the front feet.               Gonzales’s observations with skepticism
                                               or antagonism. Healthy skepticism is
How to best deal with the condition has        always appropriate, so let us examine the
remained a “hot topic” among farriers          issues on their merits.
and veterinarians. It is the aim of this
paper to explore some of the                   In my career as a veterinarian
biomechanics and often un-recognized           specializing    in     muscle      tension,
ramifications such as creating muscle          imbalance and symmetry since 1990, I
imbalance, and changes in posture that         deal daily with performance issues,
result in loss of performance and are a        saddle related problems, shoeing related
potential source of lameness.                  problems and back pain. These problems
                                               constitute as much as 90% of my
It is necessary to explore how the             practice. That has afforded me ample
syndrome alters the shape of the               opportunity to observe the relationships
shoulder and the back. Altering the            of high heel, low heel conditions on a
posture and shape of the shoulder and          first hand basis. I believe that
wither area creates problems with saddle       antagonism needs to be challenged and
fit. The resulting posture of the horse        skepticism addressed. At the very least,
affects not only saddle placement but          this subject needs to be revisited with an


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open mind. Appropriate trimming and/or           the thoracic spinous processes leads to
shoeing remains the key to soundness.            pain and primary chiropractic issues on
                                                 of the upper thoracic vertebrae as well
Postural deviation and effect on joint
angles as a result of High Heel/Low              Observe that the horse usually has a
Heel:                                            marked tendency to lean on the shoulder
                                                 of the lower heeled limb. This may leave
Let us first discuss the overall postural        some observers to conclude that the
deviations that are a direct consequence         measurements that are to be described
of the lower of the two heels. It should         are “off” only because the horse is
be clarified, at this point, that that it is     leaning on that shoulder and that if one
not the intent to address a true                 pushes the horse to an equal weight
“clubfoot.” This paper is also not               bearing that the measurements tend to
addressing an anatomically “short leg”           even up. However, this point must be
syndrome, (though to a cursory                   addressed and clarified. We must
evaluation, the limb with the lower heel         answer, why, given a choice, does the
may give the appearance of a shorter             horse choose to lean on that shoulder? It
leg). The low heeled limb is functionally        is because of the difference in heel
shorter – not anatomically shorter.              height that the horse returns to leaning
                                                 on the shoulder of the low-heeled side
A lower heel creates obvious changes in          when allowed to do so. This is the
the joint angles at the pastern, fetlock,        posture that the horse seeks as a
elbow and scapulo-humeral joint                  compensatory posture.
(shoulder joint). Compared to the limb
with the higher heel the angles on the           Assessment of High Heel/Low Heel
low-heeled limb will open (get larger),          Syndrome:
and the limb will become more vertical
than its counterpart throughout its              Commence assessment of the forelimbs
length. The pastern joints and fetlock           by observing the horse’s posture, its
will be placed in more extension (and            joint positions and angles from several
possible subluxation). The elbow angle           directions. To be meaningful, the horse
will be more open. As the                        must be on a flat even surface. The horse
scapulo/humeral joint (shoulder joint)           must be standing “squared up” on all
opens, the “point” of the shoulder will be       four feet, and allowed to be bearing
moved caudally so its position is farther        weight in its chosen posture. Ideally, the
back than on the higher heeled limb. The         assessment is best performed after the
position of the scapula becomes altered          horse has been trimmed, balanced and is
so that it rotates more vertical. This           ready to shoe. Having one hoof placed
verticality creates a bulging appearance         even 3 to 4 inches ahead of or behind the
to the shoulder and over-development of          other can alter the accuracy of the
the associated muscles on the lower              evaluation.
heeled limb. This asymmetry in the
shoulder will cause the saddle to not sit        Start the observations from six to eight
straight on the horse. The pressure that a       feet away in a position directly in front
“crooked” saddle places on one side of           of the horse. Observe progressively from


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the foot upward the position and relative       horse’s direction of stance. From this
heights of the joints. The foot with the        position it is easy to see difference in
lower heel will usually be significantly        pastern angle. In many instances, from
larger – the greater the size difference        this position, the pastern axis can be
and the longer the low heel/high heel           observed to be “broken backwards.”
condition has been present, the more            Broken pastern axis is accompanied by
difference that will be evident.                varying degree of subluxation of the
Difference in hoof size is a prime              pastern joints. The toe may appear to be
indicator that this condition exists. (Also     longer on the low heel side. The
while in this observation position,             shoulder joint can now often be seen to
evaluate the coronary band for possible         be anywhere from ½ inch to 2 inches
evidence of medial lateral balance. Note        rearward of the limb with the higher
this is only one factor in medial lateral       heel. The difference in heel height is best
balancing and may be misleading)                seen by positioning one’s self another 45
                                                degrees toward the rear of the horse and
The fetlock joint on the lower heel side        from about six to eight feet away.
is generally lower than the higher heeled
side. Next check the position of the            Next the horse should be evaluated from
styloid process of the radius. This is the      behind and slightly above the croup. In
“bump” or “top of the shelf” on the             order for a short person (or when
upper medial side of the knee (carpus). It      examining a very large horse), to
is commonly lower on the low-heeled             adequately make this evaluation, it helps
side. As the next step, evaluate and            to stand on a sturdy object of some sort.
compare the height and symmetry of the          It will be noted that the shoulder of the
points of the shoulder (scapulo-humeral         limb with the lower heel will usually
joint). Generally it will be noted that the     appear to have a significant lateral
joint appears lower on the low heel side,       “bulge” and it will appear to be higher
and that there is hypertrophy of the            than its counterpart. This is because the
descending pectoral muscles on the side         scapula has been displaced or rotated
with the higher heel. With practice it can      into a more vertical position. The
become evident that the shoulder point          shoulder with the higher heel will often
on the lower heeled side will also be           appear to slope or fall away in an
placed more rearward.                           exaggerated manner.

For an overall picture of the asymmetry,        Effects of High Heel/Low              Heel
it can be very helpful to look at the           Syndrome on Vertebral Function:
spatial symmetry created by the inner
margins of each limb and of the ventral         From a chiropractic standpoint I often
aspect of the chest wall. In other words,       find significant subluxation and pain in
look not at the limbs themselves but use        the 6th and or 7th cervical vertebrae.
them as a “picture frame” of the space          These subluxations are most often on the
between the limbs.                              side of the higher heel and relate to the
                                                animals response of keeping his eyes on
Next, stand several feet away at the            a horizontal plane. They often exhibit
shoulder at a 90-degree angle from the          muscle pain and stiffness and spasm at


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the base of the neck. Moreover, because         “bulged” laterally may strike the edge of
of dural connections, subluxations here         the panel or bar as the scapula moves
also result in tension, dural twist             through its range of motion. This can
(twisting of the dural-tube in which the        create significant muscle bruising and
spinal cord is suspended and anchored)          serves to further twist the saddle.
at the level of the poll and at the lumbo-
sacral connection.                              Because the opposite shoulder typically
                                                has more slope, the saddle may tend to
High Heel/Low Heel Affects Saddle Fit:          fall or slip to the sloping shoulder side of
                                                the horse. This is a second reason for
Now, let’s step back to again consider          pressure on the thoracic spinous
the consequences of this condition on the       processes. The problem of slipping to
fit of a saddle. The larger shoulder tends      the side is particularly troubling if the
to exhibit some degree of muscle                croup is also involved and is lower on
hypertrophy in the Trapezius muscle.            the same side. This is can occur when a
Other involved muscles may include the          high/low conditions exists in the hind
Rhomboids, Deltoid, Serratus thoracis           feet as well. More often, however when
and      Subscapularis    muscles. The          the horse is observed in motion, one side
Trapezius muscle and the Longissimus            of the croup raises more on one side than
muscle support the fork or gullet bar in        the other it relates to, muscle balance,
the fork, or head of the saddle. These          chiropractic or joint issues in the hind
muscles support the forward part of the         limbs. Regardless of cause, it creates an
bars or panels as well.                         even worse scenario for slippage when
                                                combined with shoulder asymmetry. The
Saddles are for obvious reasons built           resulting hypertonicity can and does lead
symmetrically, so when placed on a              to lameness via the following
horse      with   muscle      hypertrophy       biomechanical factors.
(enlargement) on one side, the tree
rotates diagonally into a position in order     High Heel/Low Heel Affects Horse
to establish similar contact pressure on        Performance and Soundness as well as
both sides of the “wither pocket.”              Rider Imbalance and Pain:
Torque of the saddletree, however, may
make contact and place excessive                The consequences for the horse are
pressure on one side of the lightly             muscle pain in the shoulder(s) and
covered thoracic spines and leaves more         shortening of gait. When any animal
open space on the opposing side.                experiences pain the response is to alter
Pressure exerted in areas close to bone         the posture. This leads to inappropriate
(with little muscle covering) result in a       loading of a limb while moving within
significant magnification of the pressure.      the required gaits. When the skeletal
The result of this unilateral pressure is       system support is inappropriate or
pain, and loss of ability to perform            inadequate the muscles attempt to take
bending and lateral movements. The              on    the    load.    Performance      is
pressure can also create chiropractic           compromised as the condition will lead
joint issues in the thoracic vertebrae of       to subclinical and finally outright
the withers. The shoulder that is               lameness. A rider who must alter his/her


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position and posture because of
improper position of the saddle will             High Heel/Low Heel Set Up The
eventually create further performance            Likelihood Of A “Long Toe/Low Heel
problems and increase the risk of                Syndrome”
lameness for the horse.
                                                 With regard to the foot itself, the
Most “crooked riders” have slowly                syndrome produces a long toe with the
allowed their bodies to compensate and           heel becoming under-run. This, as we
are usually quite unaware of their               know from Dr. Robert Bowker’s work at
compensation until it is brought to their        Michigan State University Veterinary
attention. Additionally, the rider may           School of Medicine, “long toe/low heel
end up with chronic back, hip or knee            syndrome”, leads to inadequate support
pain. The crooked saddle and side                in the posterior part of the foot and
slipping saddle causes the rider to place        eventually to degeneration of the digital
more weight in one stirrup than the              cushion. Digital cushion failure when
other. This, also contributes to creating        present, leads to a “broken pastern axis”
a “crooked” traveling horse and,                 that is very difficult if not impossible to
therefore, is a cause of subclinical and         correct. It is not uncommon to see large,
eventually clinical lameness. There are          flat and splayed out frogs accompanying
many other postural deviations of the            the foot with a degenerated digital
rider that can add to the problem.               cushion as the frog tries to compensate
                                                 and support the posterior portion of the
Wither vertebral chiropractic problems           foot. There is an obvious consequence to
are one of the most common causes for a          be recognized with regard to major
horse to react badly to the tightening of        factors leading to “navicular syndrome.”
the cinch or girth. The subluxations
create neuromuscular irritability in             For the many reasons presented, I feel
muscles of the shoulder and in the area          quite strongly that it is inadequate to
covered by the girth or cinch. The pain          address the foot without looking at the
from the saddle creating pressure and the        consequences on the topside of the
neuromuscular stimulation of the                 horse. Without seeking and correcting
shoulder muscles creates a chain of              the root cause (in this case the high/low
muscle shortening in the posterior               heel syndrome) any other treatment is
shoulder and forelimb muscles that can           only palliative. By properly addressing
and does lead to superficial digital             the high heel, low heel syndrome the
tendon strain and suspensory strain and          farrier can be of enormous help to both
eventual suspensory tears.                       the rider and the horse.

As a side note on performance issues,            There have been many theories
horses, typically, also often experience         advanced as to reasons for the low heel.
trouble with a lead or lead change and           Regardless of the originating factor
may tend to cross canter. In cases not           whether genetic or acquired, we are all
complicated by other musculo-skeletal            aware that the horse, once the condition
issues, it occurs in the lead on the side of     is established, will typically graze with
the higher heel.                                 the lower heeled limb advanced. It is


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certainly a reasonable theory that               primary focus should be on the low
pressure (on the heel), maintained               heeled foot.
through many grazing periods, distorts
the hoof capsule, unbalances the foot,           My experience, until recently, has lead
advances the break-over location and             to the conclusion that the best course of
causes the heel to become under-run.             corrective shoeing is the use of wedges
Pressure over time creates distortion.           as orthotic devices applied on the lower
Distortion equals an unbalanced foot.            heel in order to achieve the same heel
                                                 height and pastern angle as the more
Corrective measures for         the   High       upright foot. Sometimes it is necessary
Heel/Low Heel Syndrome:                          to also use a “lift” such as a rim (or full)
                                                 pad on the same or opposite foot as well
What is the appropriate shoeing for this         in order to create full symmetry.
condition? I feel that a cardinal rule is to     Selection of wedge height or of a rim
work primarily with the foot that has the        pad thickness (on the same or opposite
lower heel. Additional problems are              foot), is best determined after the horse
incurred if the heel of a true “clubbed          has been trimmed and balanced. Again,
foot” is lowered excessively. Structures         it is emphasized that this evaluation must
in the muscles called spindle cell               be made with the horse standing
receptors and receptors in the musculo-          squarely on a firm level surface and
tendonous portion called Golgi bodies            reassessing as earlier described
provide signals from the muscle or
tendon to the spinal cord. This data             Have the horse stand on the trial
provides information to the central              orthotics (wedges, or a combination of
nervous system (CNS) about the tension           wedges and rim pads) and evaluate for
that exists in the muscles and tendonous         improvement in symmetry. Use the same
structures.                                      examination process as previously
                                                 described. In review, check factors such
When the heel is lowered on a clubbed            as the symmetry of the space between
foot the receptors in the deep flexor            the legs, height and angle of the joints,
tendon are activated and signal the CNS          and the height of the styloid processes,
that there is too much stretch in the            Note whether the “point” of the shoulder
tendon. The response from the CNS is to          now comes into symmetry with the
issue a signal to shorten the muscle or          opposite side. Again observe from above
tendon structures to prevent injury. This        and behind to determine the effect on
response provides one of the reasons             angle and symmetry of the two scapulae.
why that by the end of a shoeing period,         Sometimes the changes observed by this
a clubfoot that has had the heel lowered         procedure are dramatic. In longstanding
usually looks as bad or worse as when            cases (especially in older horses) the
originally seen. Lowering the heel on a          changes are subtle and immediate results
non-clubber foot but one in which the            are not as evident, but will show
heels have been allowed to be high must          improvement      in    symmetry      and
be done in small increments over several         performance over the course of multiple
shoeings. It bears repeating that the            shoeings.



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Without proper attention to break-over         should be used not to carry the material
and heel support, the overall condition of     forward of the “bridge” of the frog.
the foot can be made worse with the use
of wedges. How can this be ameliorated?        If there is evidence of digital cushion
When shoeing this type of foot the             deterioration, it may be necessary to use
break-over must be set significantly back      full pads and impression material as well
to approximately 6 mm ahead of the tip         as a frog support. In younger horses
of the coffin bone. (Good quality              there is a better rate of success in re-
radiographs with the frog apex marked          directing the hoof wall growth, re-
are very helpful.) An improved heel            balancing muscle development and
support, achieved by slight lowering of        maintaining      a    back     that    can
the heel) should be used to extend the         appropriately accommodate a saddle.
buttress of the heel more rearward. The        Quite a few of such horses may be taken
wedge should then extend roughly 1/8           out of all support after a limited number
inch beyond the heel of the shoe. If           of shoeings. Older horses with very long
breakover is set as described the              standing problem and poor quality
lowering will be compensated and               digital cushion are often best kept in the
pastern axis will remain correct. If           appropriate amount of orthotic on an
necessary a higher degree of “lift” can        ongoing basis.
be utilized after extending the heel by
the lowering. The goal is to maintain          Other options include using a wedge
proper pastern axis while giving an            shoe on the low heel side, swedging the
extended heel support..                        heel, or simply leaving more heel on the
                                               low side. In our experience, the latter
Following these precautions helps to           choice is the least desirable because the
prevent the heel from further crushing. If     frog often looses the contact it needs to
the walls are already rolling under at the     assist in any possible restoration of the
heels it is necessary to trim them lower       digital cushion and allows the heels to
yet to the level where there is sound wall     curve inward putting pressure on the
growing in the proper direction and not        navicular area. If a higher heel is chosen,
rolling under. It follows that radical         it should be accompanied by impression
trimming must be followed by using a           material and a frog support on the solar
larger wedge or other means in order to        surface.
create the appropriate heel height and
pastern angle. For most cases, where           New Information On A Potentially
wedges are used, the author prefers an         Valuable Shoeing Technique To
“open” bar wedge and where indicated,          Ameliorate The Problems Of High
rim pads instead of full pads. Frog            Heel/Low Heel Syndrome:
supports may be helpful. A technique
using an acrylic product such as               In the last three months of 2005 until the
“Equithane” can be used to build both          present, a superb farrier with whom I
sole and heel as well as provide an            work suggested that we try just turning
impression material effect to bring the        the last (approximately) one inch of the
low heel to balance with the high heel         heels of the shoe down on the affected
and support the digital cushion. Caution       foot. This can be very simply done


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Revised February 06


without requiring a forge or any
elaborate equipment. Moreover, the shoe       Muscle Rebalancing:
can be turned down to any required
degree to match the degree of lift needed     For muscle re-balancing to occur
to equal the height of the higher heeled      following postural correction, the horse
side. Breakover and heel length must          must be in work. There is always
still be as needed to create appropriate      concern with how much work is
biomechanics.                                 acceptable and how soon should work
                                              resume after shoeing corrections have
To date we have had success with a            been done. It is, of course, always err on
large number of horses (approximately         the conservative side and work the horse
50 up until time of this revision in Feb      lightly for the first week or ten days.
06). To date we have not knowingly            However, I have seen horses remain in
produced any untoward effects and have        athletic competition immediately after
seen a fair percentage of cases show a        the shoeing changes. Even with no
more appropriate angle of heel growth.        decrease in intensity or schedule of
We have had no problem with keeping           competition, they have suffered no
these shoes on during the shoeing             apparent negative effects.
period. Shoes used have been of both
aluminum and of steel. Shoes of both          Conclusion:
types have been used with glue-on
procedures as well as conventional            One last point – if one is not happy with
nailing.                                      the results it is a simple matter to remove
                                              the orthotics or altered shoe at any time.
Younger horses may respond to therapy         However, I believe that if the farrier
well enough to become fully rebalanced.       considers all the factors and shoes
Older horses may require some form of         appropriately        according     to   the
correction during the remainder of their      principles discussed, the results will be
riding career.                                positive for all concerned.




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