Practitioners overcome dearth of foot orthoses data

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Biomechanics July 2005 www.biomech.com

Practitioners overcome dearth of foot orthoses data

By: Andria Segedy

Foot orthoses can't get no respect. Though prefabs are the first-line

self-medication solution for many people and custom orthoses are

prescribed with great frequency, hard data about their efficacy are

scarce. Practitioners are finding ways to overcome that problem.

Stuart Pressman, CO, CPed, was frustrated with the limited solutions

he saw to problems of the foot. Working within a pharmacy/medical

supply business as Pressman Orthotics, the certified orthotist found

more and more people had foot problems and nobody had the answers.

His response was to become a certified pedorthist and to open Sole-

lutions Footwear in Pembroke Pines, FL.

In 1995 Pressman returned to school to study pedorthics and to better

understand the biomechanics of the foot in order to come up with

solutions for his patients' foot problems. Four years ago he opened

Sole-lutions, where today 70% of his patients are from physician and

physical therapist referrals. The rest are walk-ins to his 1400-

square-foot retail store. He markets his business by direct mail to

and direct contact with those referral sources.

" When you become an orthotist, you learn something about the foot,

but not anywhere near the extensive detail you do going to school for

pedorthics, " Pressman said. " I learned the details of how the foot

affects the rest of the body. It's almost like an internist becoming

a specialist. "

He also pores over industry journals for new ideas and products and

attends professional conventions.

Sole-lutions' patients have a range of issues, from diabetes to

arthritis to pain. The number one foot problem Pressman sees, though,

is plantar fasciitis, followed by metatarsalgia.

" A lot of people are hooked on their beautiful shoes that are the

wrong size and fit, and they eventually will be in to see me, "

Pressman said.

Pressman said Sole-lutions sells three kinds of inserts. In stock at

all times are 30 to 40 varieties of over-the-counter inserts, priced

from $12 to $65, made by different companies. Full custom-molded

insoles, accommodative or corrective, cost $300, although other

businesses charge as much as $450, he said. Semicustom insoles allow

him to piece together components to match a foot. He sells these

inserts for $90 to $150.

The basis for a particular choice is patient need, Pressman said,

while the pricing differences also give some consumers options based

on economics. Pressman said he starts with the lowest priced solution

he thinks will work.

One of the meetings Pressman attends is the Pedorthic Footwear

Association's annual symposium, where last year he learned about X-

Static, an antimicrobial, silver-based material he now uses in

orthotic inserts he fabricates and in socks he sells (see " Precious

Metal: Foot care takes a shine to silver, " February, page 26). While

X-Static is an exception, for the most part Pressman finds that few

of the new materials or products on the market are appreciably better

than what he already uses. He also notes that some of the newer

products do not work as well with other pieces of the finished

insert.

" I'm used to the old materials, the ones I have had proven success

with, " he said. " This new material (X-Static) works well with what I

already use. "

He misses Recoil, a heat-conformable urethane, taken off the market a

few years ago.

" It was an excellent material, " Pressman said. " I don't know why they

stopped manufacturing it. It was good for patients with diabetes,

good for patients with arthritis. Its shock absorbency came from a

sponge-like material with the ability to rebound. It was heat-

moldable and glueable. It worked great. "

He's also able to weave his newest find into custom-molded inserts.

The X-Static material helps kill odor and bacteria and prevent

infections to the foot, Pressman said. The material is available in

socks and Acor shoes for diabetic patients-silver's antimicrobial

properties help discourage infection in diabetic wounds-and in socks

and inserts he sells mostly to athletes. Athletic shoe manufacturers

are jumping in, too. Sports will start using X-Static in its

running shoes next season, he said.

" I've used the X-Static mostly with athletes who have sweaty feet and

issues with odor, " Pressman said.

The patient-athlete also is more willing to pay the higher price of a

product made with X-Static, Pressman said, adding that he charges an

additional $20 per pair to use the X-Static material in custom

orthoses.

Unlike products and materials, insurance reimbursement challenges

haven't changed with time, Pressman said. He does accept assignments

for patients under Medicare's Therapeutic Shoe Bill, but not other

insurance plans.

" Generally, orthotic inserts are not covered or there is a question

mark on an individual insurance plan, so I won't accept insurance.

But we will do the billing for the patients, " he said.

Illinois outcomes

The lower limb and foot patients at Springfield Clinic and its

Diabetic Foot Clinic in central Illinois usually find themselves

subjects of research conducted by staff orthotist Geza F. Kogler,

PhD, CO. The aim of his current study is to determine how the clinic

compares to national statistics in diabetic patient outcomes and what

can be done to better educate patients with diabetes who might face

limb amputation, Kogler said.

Along with the potential for better clinical results, Kogler said,

research can make a difference to payers, giving an example from the

late 1990s.

" There is one orthopedic foot and ankle surgeon in central Illinois, "

Kogler said. " He knew the only way his patients could be treated for

plantar fasciitis was to send them to me and have me prescribe a

custom foot orthosis I designed based on my 1996 biomechanical

study. " 1

At the time, none of the area insurance carriers would reimburse for

the device, Kogler said. The surgeon and Kogler began documenting the

cost of the surgeon treating the case-including x-rays, multiple

office visits, injections, and physical therapy-versus the cost of

the orthoses from Kogler. The cost of the surgeon treating the case

was alarming, Kogler said, although he could not recall specific

figures. At the time, the cost of the orthoses was $250 to $300.

Health Alliance (based in Urbana, IL) is still one of the only

carriers to cover this device, he said. Health Alliance's decision

was based on Kogler's paper and the financial data comparison he and

the surgeon provided.

" We had a solution that was reliable and predictable, " Kogler

said. " But I can't take it up as one of my second jobs to go to each

provider. "

Reimbursed or not, Kogler has done enough research that he believes

his devices help improve foot function for his customers. He doesn't

stock any prefabricated devices.

" Almost all of the orthoses I prescribe and fit are custom-molded and

fabricated, " Kogler said. " The design configuration of most of my

foot orthoses is based on biomechanical research studies I have

conducted. "

Working at a diabetic foot clinic means Kogler sees a lot of pressure

sores.

" Orthotists dealing with diabetic foot-related problems are

essentially 'pressure managers' for the feet, " he said. " Their

success depends on a solid understanding of foot biomechanics that

allows them to properly design an orthosis. "

An appreciation for the mechanisms responsible for wound healing as

it relates to diabetes and the vascular-deficient limb are also

important.

" The medial longitudinal arch has the potential to reduce pressure to

the first metatarsal head and the medial heel an average of 28%

compared to a flat insole, " Kogler said. " A metatarsal support and a

concave relief for metatarsals also have significant pressure-

relieving capabilities for the metatarsals. "

His research has focused on medial longitudinal arch supports and

wedges, which he thinks may be of benefit, though there is little

data yet to support his clinical observations.

" According to our hypothesis, orthoses that are effective as arch

supports would reduce tension within the plantar aponeurosis, " Kogler

said.

As part of a cadaver study, he designed a biomechanical test to

evaluate arch support mechanisms by measuring the strain within the

plantar fascia via an implanted strain transducer.1 His team of

investigators evaluated six different types of arch supports.

" Though a couple were effective as arch supports, you can't call all

of the devices tested arch supports because they are not changing the

tension within the plantar aponeurosis, " he said.

An arch support acts like a truss, Kogler said.

" We defined an arch support as a structure that supports the skeletal

arch, not just the soft tissue, and displays a quantifiable reduction

in tension in the plantar fascia, " Kogler said.

A definition accepted by the orthopedic, podiatric, and other

footwear medical specialties, this was one that could be demonstrated

biomechanically.

" Most over-the-counter foot orthoses just compress soft tissue and do

not support the arch, as they claim, " He said.

Kogler did a similar study,2 also cadaveric, on the influence of

medial and lateral orthotic wedges on foot function. Results showed

that a wedge under the lateral aspect of the forefoot decreased

strain on the plantar aponeurosis and a wedge under the medial aspect

increased the strain (see table).

Shape and function

On the Northwest coast, researchers at the Veteran Administration's

Center for Excellence in Limb Loss Prevention and Prosthetic

Engineering in Seattle are studying the effects of foot shape on foot

function. Results could provide the practitioner community with

documented information on how foot structure affects function,

according to principal investigator and research health scientist

Ledoux, PhD.

Existing studies on foot shape and function often have a subjective

component,3 Ledoux said. His research in Seattle is objective.

" One thing we are interested in is how the shape of the foot relates

to diabetic ulceration. We've come up with an objective, three-

dimensional way of quantifying the foot shape based on computed

tomography scans of a person's foot, " Ledoux said.4

To relate the shape of the foot to the plantar pressure it produces,

he's also measuring plantar pressure with an emed pressure plate.

Weight-bearing CT scans were taken of 40 feet from 40 subjects: 10

each pes planus (flat) feet with and without pain, 10 neutrally

aligned feet, and 10 pes cavus (high-arch) feet.

" We're exploring whether the shape of the talus is different in

people who have painful flat feet and pain in their arches, " Ledoux

said. " This is unrelated to diabetic foot ulceration. However,

diabetic foot ulceration could also be related to the shape of a

person's foot. "

Andria Segedy is a contributing editor to BioMechanics.

References

1. Kogler GF, idis SE, JP. Biomechanics of longitudinal

arch support mechanisms in foot orthoses and their effect on plantar

aponeurosis strain. Clin Biomech (Bristol, Avon), 1996;11(5):243-252.

2. Kogler GF, Veer FB, idis SE, JP. The influence of

medial and lateral placement of orthotic wedges on loading of the

plantar aponeurosis. J Bone Joint Surg 1999;81-A(10): 1403-1413.

3. Razeghi M, Batt ME. Foot type classification: a critical review of

current methods. Gait Posture. 2002 Jun;15(3):282-291.

4. Camacho DL, Ledoux WR, Rohr ES, et al. A three-dimensional,

anatomically detailed foot model: a foundation for a finite element

simulation and means of quantifying foot-bone position. J Rehabil Res

Dev 2002;39(3):401-410.