Traditional O&P has focused on fitting patients with shoe orthotics
to treat the patients’ symptoms but not necessarily the pathology that has
caused the symptoms. Researchers are beginning to find, however, that generic
orthotic interventions will not necessarily help all patients with those
symptoms.
Instead, researchers have begun to look at mechanical pathways to
determine which orthotic intervention is the best, Paul R. Scherer, DPM,
general manager and chief executive officer of ProLab Orthotics in Napa,
Calif., and clinical professor at Western University School of Podiatric
Medicine in Pomona, Calif., said.
Orthotic revolution
Up until recently, orthotics educational programs have taught foot and
ankle biomechanics first, then the orthotic therapy. Now, institutions are
opting to teach the origins of the pathology first, and then cover the orthotic
intervention.
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| Paul R. Scherer |
“Specifically in the orthotic industry, it’s going on right
now. This is a revolution,” Scherer said. “Half the people have one
foot on one side of this educational philosophy and the other foot on the other
side because it’s just beginning to change.”
Consider the mechanical origin of a common pathology like
plantar fasciitis.
“If you asked, probably 50% of the podiatrists and 100% of the
orthotists, they would say the etiology is pronation,” he said.
“It’s funny logic: orthotics were used to treat plantar fasciitis and
orthotics prevent pronation. Therefore plantar fasciitis must be caused by
pronation.”
This is a severely flawed logic that does not necessarily benefit the
patient, he said.
Contrary to belief
But in 1996, Géza F. Kogler, PhD, CO, BCO, LO, LPed, studied this
pathology and “unequivocally proved that it’s the motion of the
midtarsal joint that stretches the plantar fascia, not pronation of the
subtalar joint.”
In fact, Kogler found in his cadaveric study that using a varus wedge to
supinate the midtarsal joint increased the tension on the plantar fascia,
Scherer said.
Contrary to longstanding belief, when he pronated the subtalar joint
with a valgus wedge under the forefoot, he did not stretch the plantar fascia,
but rather decreased the tension on it. In some cases, orthotists had merely
gotten lucky when making orthotics to prevent pronation of the subtalar joint
because it actually pronated the midtarsal joint — that same device Kogler
found to pronate also supinated the subtalar, he said.
Another mistreated pathology is pes cavus foot, where a high-arched foot
brings the patient pain under the forefoot and other symptoms. The default
treatment for this condition was to attempt to lower the arch by pronating the
foot with an orthotic. Scherer told O&P Business News that
research, however, shows that, 80% of the pes cavus incidence stems from
weakness of the anterior muscle groups and a subsequent overpowering of the
peroneus longus. Instead of fitting the patient with an orthotic that pronates
the subtalar joint, orthotists should prevent compensation of the rigid
forefoot valgus produced by the peroneus longus muscle with a forefoot valgus
wedge.
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| Traditional orthotics education focuses on biomechanics before orthotic therapy but those patterns are starting to reverse. |
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| © iStockphoto.com/Juanmonino |
“There are some studies that show that the symptoms seem to get
better this way,” Scherer said.
Pediatric pathology
The pediatric population has been facing the opposite pathology from pes
cavus: pediatric hypermobile flatfoot. He pointed out that, as the incidence of
overweight and obese children has risen throughout the United States —
more than 18% of children aged 6-11 years were obese in 2006, up from less than
4% of children in 1971 — the percentage of the pediatric population with
flatfeet also has risen — from about 2% to 30% currently.
Of the comorbidities of obesity, hypermobile flatfoot ranks fourth,
behind pediatric hypertension, diabetes and coronary heart disease, ranked
first through third, respectively.
A study in 2001 by Lisa Selby-Silverstein, PT, PhD, NCS, looked at
children with Down syndrome, all who pathologically have both an overweight
problem as well as flatfeet.
“From the results of that study, using orthoses to improve the
children’s gait pattern, hypotheses have developed that spring ligament,
which is one of the major developing ligaments in the foot, is overstretched by
the weight, causing a collapse of the foot,” Scherer explained.
An abnormal foot position during growth will cause ligaments and bones
to develop around the abnormal position, resulting in an abnormal anatomy and
function in adulthood.
“Can we put the children’s feet that are hypermobile and flat
in a more normal position, take the strain off and decrease the moment on the
spring ligament, by holding the foot in a better position — and allowing
the foot to develop in that position? Would that result in an adult foot that
is more normal?” Scherer asked.
He said he thinks the answer is yes. To know for certain, the field will
need a longitudinal study on these children, and currently he is working on
securing funding for this research. This research is necessary because the
answer is in treating the pathology, not in treating the deformity, he said.
Follow the pathology
“We have to follow the pathology, or this new pathology-specific
approach, as we do in everything else,” he said. “It’s happening
in all of medicine.”
Specifying orthoses to pathology results in more consistent results for
patients. To get more positive outcomes, orthotists should review each
patient’s condition individually, instead of opting for one-size-fits-all
orthotic treatment.
“You can get a 50% outcome by putting prefabs in their shoes,”
he said. “Is 50% clinical outcomes acceptable to you?” — by
Stephanie Z. Pavlou
Disclosure: Paul R. Scherer, DPM, is
the chief executive officer and owner of ProLab Orthotics.
I believe Scherer’s information is correct. It is quite interesting
since I have learned these (forefoot) methods of correction several times, over
the past two decades. However, these methods of correction — whether it
was for plantar fasciitis or for a supinated foot — were secondary to the
original methods of calcaneous posting that were originally taught, primarily
due to the lack of research to warrant these teachings. The original methods of
fabricating foot orthoses were typically posted at the heel. While there is a
necessity for rear foot posting of an orthosis, it is not always the case. So
which is the proper method of correcting foot orthoses? That is where the
pathology Scherer is reporting on comes into play.
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| Stuart Pressman |
In the case of the pediatric foot, it is true that obesity plays a role
in the development of the foot. Hypermobility is common in the pediatric
community, as I have witnessed on an almost daily basis through my practice.
Assisting children from the age of 7 on up through their teens, I have
witnessed remarkable results with the use of the correct foot orthoses in these
children. The proper orthotic regiment can assist the muscles, tendons and
ligaments to develop in a normal position.
I do believe research in this area would be beneficial and is necessary
to progressing the field of pathology-specific foot orthoses. I don’t
believe that the field of over-the-counter (OTC) foot orthoses is a 50-50
outcome. At least not in the case of OTC orthoses being dispensed by an
orthotist/pedorthist. However, there are very few of us around the United
States who dispense the wide variety of OTC orthotics, as well as
custom-fabricated orthotics available in today’s marketplace.
— Stuart Pressman, CO, CPed
Pressman
Orthotics Inc., Sole-lutions Footwear
Disclosure: Stuart Pressman, CO,
CPed, has no direct financial interest in any companies mentioned in this
article.
