> LOW HEEL / HIGH HEEL SYNDROME - UNRECOGNIZED PROBLEMS & CONSIDERATIONS > > by Dr. Kerry J. Ridgway, DVM
High Heel / Low Heel Set Up The Likelihood Of A "Long Toe / Low Heel Syndrome": With regard to the foot itself, the syndrome produces a long toe with the heel becoming under-run. This, as we know from Dr. Robert Bowker's work at Michigan State University Veterinary School of Medicine, "long toe / low heel syndrome", leads to inadequate support in the posterior part of the foot and eventually to degeneration of the digital cushion. Digital cushion failure when present, leads to a "broken pastern axis" that is very difficult and in some cases, impossible to correct. It is not uncommon to see large, flat and splayed out frogs accompanying the foot with a degenerated digital cushion as the frog tries to compensate and support the posterior portion of the foot. There is an obvious consequence to be recognized with regard to major factors leading to "navicular syndrome." Among these factors a horse with long toe/low heel tends to "break" the pastern axis and place much more stress on the deep digital flexor tendon. The deep flexor tendon is, in turn, putting pressure on the navicular bursa and impar ligament. There is a wonderful adage that when one finds a problem look elsewhere for the cause. An unacceptable level of heel height asymmetry, I propose, is the root cause for asymmetry and pathology at the level of the topline. But, for the many reasons presented, I feel quite strongly that it is inadequate to address the foot without appreciating the consequences on the topside of the horse. Without seeking and correcting the root cause (in this case the high/low heel syndrome) any other treatment is only palliative. By properly addressing the high heel, low heel syndrome the farrier can be of enormous help to both the rider and the horse. There have been many theories advanced as to reasons for the low heel. Regardless of the originating factor whether genetic or acquired, we are all aware that the horse, once the condition is established, will typically graze with the lower heeled limb advanced. It is certainly a reasonable theory that pressure (on the heel), maintained through many grazing periods, distorts the hoof capsule, unbalances the foot, advances the break-over location and causes the heel to become under-run. Pressure over time creates distortion. Distortion equals an unbalanced foot. Corrective measures for the High Heel/Low Heel Syndrome: Should one universally be concerned and looking to correct every horse who as heel height asymmetry? Absolutely not! I do not advocate any of the several possible "corrections" such as wedges, lifts, etc. unless by thorough examination (static and moving) and the history and way of going indicate that interference is needed. I do this by evaluation of reactive trigger and acupuncture points, evidence of inadequate or inappropriate vertebral segment motion and muscle palpation and recognition of hypertonicity within a muscle or group of muscles. The role of the saddle and its proper fit needs to be critically evaluated as it may be a very key link. This is an area where well educated body workers, chiropractors and acupuncturists can be of great help to the veterinary profession. What is the appropriate shoeing for this condition? I feel that a cardinal rule is to work primarily with the foot that has the lower heel. Additional problems are incurred if the heel of a true "clubbed foot" is lowered excessively. Structures in the muscles called spindle cell receptors and receptors in the musculo-tendonous portion called Golgi bodies provide signals from the muscle or tendon to the spinal cord. This data provides information to the central nervous system (CNS) about the tension that exists in the muscles and tendonous structures. When the heel is lowered on a clubbed foot the receptors in the deep flexor tendon are activated and signal the CNS that there is too much stretch in the tendon. The response from the CNS is to issue a signal to shorten the muscle or tendon structures to prevent injury. This response provides one of the reasons why that by the end of a shoeing period, a clubfoot that has had the heel lowered usually looks as bad or worse as when originally seen. Lowering the heel on a non-clubber foot but one in which the heels have been allowed to be high must be done in small increments over several shoeings. It bears repeating that the primary focus should be on the low heeled foot. I make no claims to be a farrier. I have undertaken indepth study of foot issues, shoeing and podiatry for many years now, because no horse can be corrected if the feet are no reasonably balanced. My work will not achieve long range solution without attention to the feet. My experience, until recently, had lead to the conclusion that the best course of corrective shoeing is the use of wedges as orthotic devices applied on the lower heel in order to achieve the same heel height and pastern angle as the more upright foot. Sometimes it is necessary to also use a "lift" such as a rim (or full) pad on the same or opposite foot as well in order to create symmetry. Selection of wedge height or of a rim pad thickness (on the same or opposite foot), is best determined after the horse has been trimmed and balanced. Again, it is emphasized that this evaluation must be made with the horse standing squarely on a firm level surface and reassessing as earlier described Have the horse stand on the trial orthotics (wedges, or a combination of wedges and rim pads) and evaluate for improvement in symmetry. Use the same examination process as previously described. In review, check factors such as the symmetry of the space between the legs, height and angle of the joints, and the height of the styloid processes, Note whether the "point" of the shoulder now comes into symmetry with the opposite side. Again observe from above and behind to determine the effect on angle and symmetry of the two scapulae. Sometimes the changes observed by this procedure are dramatic. In longstanding cases (especially in older horses) the changes are subtle and immediate results are not as evident, but will show improvement in symmetry and performance over the course of multiple shoeings. Without proper attention to break-over and heel support, the overall condition of the foot can be made worse with the use of wedges. How can this be ameliorated? When shoeing this type of foot the break-over must be set significantly back to approximately 6 mm ahead of the tip of the coffin bone. (Good quality radiographs with the frog apex marked are very helpful.) An improved heel support, often achieved by slight lowering of the heel) should be used to extend the buttress of the heel more rearward. The wedge should then extend roughly 1/8 inch beyond the heel of the shoe. If breakover is set as described the lowering will be compensated and pastern axis will remain correct. If necessary a higher degree of "lift" can be utilized after extending the heel by the lowering. The goal is to maintain proper pastern axis while giving an extended heel support.. Following these precautions helps to prevent the heel from further crushing. If the walls are already rolling under at the heels it is necessary to trim them lower yet to the level where there is sound wall growing in the proper direction and not rolling under. It follows that radical trimming must be followed by using a larger wedge or other means in order to create the appropriate heel height and pastern angle. For most cases, where wedges are used, the author prefers an "open" bar wedge and where indicated, rim pads instead of full pads. Frog supports may be helpful. A technique using an acrylic product such as "Equithane" can be used to build both sole and heel as well as provide an impression material effect to bring the low heel to balance with the high heel and support the digital cushion. Caution should be used not to carry the material forward of the "bridge" of the frog. If there is evidence of digital cushion deterioration, it may be necessary to use full pads and impression material as well as a frog support. In younger horses there is a better rate of success in re-directing the hoof wall growth, re-balancing muscle development and maintaining a back that can appropriately accommodate a saddle. Quite a few of such horses may be taken out of all support after a limited number of shoeings. Older horses with very long standing problem and poor quality digital cushion are often best kept in the appropriate amount of orthotic on an ongoing basis. Other options include using a wedge shoe on the low heel side, swedging the heel, or simply leaving more heel on the low side. In our experience, the latter choice is the least desirable because the frog often looses the contact it needs to assist in any possible restoration of the digital cushion and allows the heels to curve inward putting pressure on the navicular area. If a higher heel is chosen, it should be accompanied by impression material and a frog support on the solar surface. New Information On A Potentially Valuable Shoeing Technique To Ameliorate The Problems Of High Heel/Low Heel Syndrome: In the last three months of 2005 until the present, a superb farrier with whom I work suggested that we try just turning the last (approximately) one inch of the heels of the shoe down on the affected foot. This can be very simply done without requiring a forge or any elaborate equipment. Moreover, the shoe can be turned down to any required degree to match the degree of lift needed to equal the height of the higher heeled side. Breakover and heel length must still be as needed to create appropriate biomechanics. To date we have had success with a large number of horses (approximately 100 up until time of this revision). To date we have not knowingly produced any untoward effects and have seen a fair percentage of cases show a more appropriate angle of heel growth. We have had no problem with keeping these shoes on during the shoeing period. Shoes used have been of both aluminum and of steel. Shoes of both types have been used with glue-on procedures as well as conventional nailing. This idea needs further sturdy and use in different environmental conditions. Younger horses may respond to therapy well enough to become fully rebalanced. Older horses may require some form of correction during the remainder of their riding career. Muscle Rebalancing: For muscle re-balancing to occur following postural correction, the horse must be in work. There is always concern with how much work is acceptable and how soon should work resume after shoeing corrections have been done. It is, of course, always err on the conservative side and work the horse lightly for the first week or ten days. However, I have seen horses remain in athletic competition immediately after the shoeing changes. Even with no decrease in intensity or schedule of competition, they have suffered no apparent negative effects. I have seen a number of cases in which good barefoot trimming procedures have corrected the pathologic effects and brought the feet into good balance. There are many schools of thought and on barefoot trimming. I have seen the best results from a relatively conservative (not highly invasive type of trimming). For those interested, I would refer you to http://www.hoofrehab.com for more information. Since so many riders are themselves imbalanced, proper schooling and riding exercises (beyond the scope of this paper) can also play an important part. I very much believe that an interdisciplinary approach to this and most other horse problems as it often opens other possibilities as to cause, effect, and solution. Therefore, I welcome input from all sources. Conclusion: One last point - if one is not happy with the results it is a simple matter to remove the orthotics or altered shoe at any time. However, I believe that if the farrier considers all the factors and shoes appropriately according to the principles discussed, the results will be positive for all concerned.
