MARCH 2011 • PODIATRY MANAGEMENTwww.podiatrym.com 97

Orthotic therapy has changedconsiderably in the pastdecade as new studies have

provided evidence on the efficacyof foot orthoses in treating many ofthe most common pathologies seenin podiatric clinics. Research hasnot only shown efficacy but hasalso indicated how orthotic pre-scriptions should be written inorder to achieve optimum clinicaloutcomes for specific pathologies.

Unfortunately, many podia-trists—and orthotic laboratories—have not kept abreast of recent liter-ature and continue to practice lessthan optimum orthotic therapy.

This leads to a “chicken or the egg”scenario where the following occurs:

• Doctors do not practice evi-dence-based treatment when pre-scribing orthoses, resulting in �

• Poor clinical outcomes, result-ing in �

• Doctor frustration with or-thotic therapy, resulting in �

• Doctors ignoring research andeducation that can help themachieve better clinical outcomes.

EBMEvidence-based medicine (EBM)

shows that orthoses do work totreat many of the common prob-lems seen in podiatric clinics. Butpracticing EBM also may require

that doctors alter how they ap-proach orthotic therapy. This in-cludes ensuring that negative cast-ing follows what the literaturedemonstrates are the most effectivemethods, orthotic prescriptionsthat follow EBM tenets, and choos-ing orthotic labs that are able to fillthese prescriptions accurately.

In addition, podiatrists who fol-low EBM must often upgrade theirorthotic troubleshooting skills.Those practitioners who practiceevidence-based orthotic therapy bycapturing EBM based images of thefoot, writing EBM prescriptions,using labs that can fill EBM pre-scriptions and have excellent or-

By Lawrence Huppin, DPM

Continued on page 98

Evidence-BasedMedicine(EMB) andOrthoticTherapyEBM supportsorthosis modificationsand troubleshooting.

©Pa

lto|D

ream

stim

e.co

m

O R T H O T I C S & B I O M E C H A N I C SO R T H O T I C S & B I O M E C H A N I C S

showing that semi-rigid or-thoses worn in supportiveshoes were an effective treat-ment for metatarsalgia. Sup-portive shoes worn alone orworn with soft orthoses didnot provide pain relief formetatarsalgia.2

Plantar FasciitisA 1996 cadaveric study

by Kogler demonstrated in1996 that orthoses whichconform closely to the archof the foot more effectivelyreduce plantar fascia ten-sion.3 A follow-up study in1999 found that valgus forefootwedging decreased tension on theplantar fascia, while varus wedgingincreased tension. This studyshowed that the most effective wayto decrease strain on the plantarfascia is to use orthoses that con-form close to the arch of the footand to evert the forefoot.4

Hallux LimitusRoukis, et al. found that preven-

tion of first ray plantarflexion re-sulted in decreased first metatar-sophalangeal joint (MPJ) dorsiflex-ion (hallux limitus). Subsequently,they also found that when the firstray was allowed to plantarflex, therewas an increase in available firstMPJ dorsiflexion.5 This is indicativethat orthoses that prevent first ray

dorsiflexion (or-thoses that con-form close to thearch when thefirst ray is dorsi-flexed) enhancewindlass function.In a 2000 study,Harradine foundthat increasing ev-ersion of the heel,which acts to dor-siflex the first rayas the medial fore-foot is jammedinto the support-ing surface, de-creased availabledorsiflexion of thefirst MPJ.6 Thesestudies indicatethat orthoseswhich preventfirst ray dorsiflex-ion (orthoses that

thotic troubleshooting skills will bethe most successful at providing re-lief to their patients and building asuccessful orthotic therapy practice.

Evidence-Based OrthoticPrescriptions

Evidence in the literature indi-cates what the most effective or-thotic prescriptions are for specificpathologies. For example, a numberof studies have shown that orthosesthat conform very close to the archof the foot are more effective formany of the pathologies most com-monly treated with custom or-thoses. Let’s look at a few examplesof those pathologies and their asso-ciated studies.

MetatarsalgiaResearchers out of George Wash-

ington University studied the effectof a total contact insert (TCI) and ametatarsal pad (MP) on metatarsalhead peak plantar pressures andpressure-time integrals. Their conclu-sion was that the total contact insertand a metatarsal pad caused substan-tial and additive reductions of pres-sures under the metatarsal heads.The TCI reduces excessive pressuresat the metatarsal heads by increasingthe contact area of weight-bearingforces. The MP acts by compressingthe soft tissues proximal to themetatarsal headsand relieving com-pression at themetatarsal heads.1

A 2000 studyby Chalmers com-pared the effects ofsemi-rigid and softorthoses worn insupportive shoes,and supportiveshoes worn alone,on metatarsal pha-langeal joint painin patients withrheumatoid arthri-tis. Their resultsshowed that semi-rigid orthoses hadsignificant effecton pain. Soft or-thoses did notshow a significanteffect on pain, nordid shoes alone,

conform close to the arch when thefirst ray is plantarflexed during cast-ing) enhance windlass function.6

Other pathologies with peer-re-viewed evidence of the efficacy offoot orthoses include adult-ac-quired flat foot, rheumatoid arthri-tis foot, pes cavus, patella-femoraldysfunction, osteoarthritis of themedial knee, tarsal tunnel syn-drome, and lateral ankle instability.

Evidenced-Based OrthoticPrescriptions May ChangeYour Orthoses

One of the common factorsfound in writing orthotic prescrip-tions is that, for many pathologies,studies indicate that orthoses thatconform closer to the arch of thefoot (Figure 1) are likely to providebetter clinical outcomes than thosethat gap from the arch (Figure 2). Itis critical that podiatrists be awareof this as many custom orthosesprescribed by podiatrists are madein such a way that the orthoticshell does not conform closely tothe arch of the foot. There are sev-eral situations that can lead to anorthosis that does not adequatelyconform to the arch of the foot.These include:

• Using foam box casting tech-nique: McPoil, et al. compared non-weight-bearing (NWB) vs. semi-weight-bearing (SWB) casting of thefeet (plaster negative suspensioncasts vs. foam impression casts).The authors found that NWB plas-ter casting was superior to foambox SWB casting since the SWBcasting resulted in artificial varus inthe forefoot.7 Laughton and Mc-Clay-Davis did a similar study com-

EMB...

Continued on page 99

98 www.podiatrym.comPODIATRY MANAGEMENT • MARCH 2011

Figure 2: This “total contact orthosis” conformstightly to the arch of the foot.

Figure 1: For many of the pathologiesmost commonly treated with orthoses,studies indicate that orthoses that con-form closer to the arch of the foot aremore effective than those that gap fromthe arch. This orthosis is gapping fromthe arch of the foot.

MARCH 2011 • PODIATRY MANAGEMENTwww.podiatrym.com 99

to require occasional adjustmentsand troubleshooting. It becomesimperative that in order to providethe best possible outcomes with or-thotic therapy, practitioners mustnot only write prescriptions thatfollow best practices but also havetroubleshooting skills and optimal-ly be able to make orthotic adjust-ments in their clinics.

In summary, practitioners whowrite orthotic prescriptions basedon evidence in the literature andonly use labs that will fill their pre-scription as written are likely to see:

• Improved clinical outcomes• Orthoses that tend to have high-

er arches, wider widths, deeper heelcups, and require more modifications.

• Orthoses that will occasional-ly have need for adjustment.

Podiatrists’ Options forOrthosis Troubleshooting

If a podiatrist is going to practiceEBM orthotic therapy, certain basicproficiencies are required. Orthoticprescriptions must be written to treatthe pathology, not to eliminate anyneed for orthotic adjustment. Occa-sional troubleshooting and adjust-ment of orthoses will be necessary forthose practitioners who follow EBMwhen prescribing orthoses. When de-ciding whether to follow EBM intheir orthotic therapy and whether tomake orthotic adjustments in theiroffices, podiatrists can choose one ofthe following scenarios:

1) Prescribe orthoses thatrarely, if ever, require adjustment.These tend to be orthoses with arch-

paring two casting techniques,NWB plaster vs. SWB foam impres-sions.8 They found that NWB cast-ing had good agreement with theclinically measured forefoot-to-rear-foot relationship. SWB foam im-pressions had poor forefoot-to-rear-foot agreement and the SWB footresulted in an artificial increase invarus, likely resulting from first raydorsiflexion due to weight-bearing.This study recommended NWB footimaging as the most reliable andvalid technique.

• Improper Prescriptions: Foran orthosis to conform closely tothe arch of the foot, the doctorshould prescribe a minimum fill.Any medial arch fill greater thanminimum will lead to a device thatgaps from the arch.

• Overfill of the medial arch bythe lab: Maintaining close contouralso requires that the orthotic labnot overfill the medial arch. Toachieve this, practitioners must care-fully evaluate the work of their labto ensure that their prescription isfollowed. (Figure 3) Labs may some-times overfill the arch in reaction todemands from their customers. Po-diatrists who lack skill or desire totroubleshoot orthoses demand thattheir labs manufacture a “no adjust-ment necessary” orthosis. Labs re-spond by overfilling the medial archof the positive cast to make orthosesthat have lower arches. The result isa device that rarely causes arch irri-tation but also rarely provides opti-mum clinical outcomes.

Close arch contour can beachieved with an orthosis prescrip-tion that includes minimum castfill and mild inversion.

Podiatrists who do not capturean image or cast of the foot that fol-lows EBM criteria, who do not writeprescriptions with minimum castfill, or use orthotic labs which rou-tinely overfill the medial arch willsupply their patients with orthosesthat do not conform well to the archof the foot and provide less than op-timum clinical outcomes for manyof the most common pathologiestreated with foot orthoses.

Orthoses that conform closer tothe arch, are wider or have deeperheel cups, or have additions such asmetatarsal pads are also more likely

es that don’t conform well to thearch of the foot, and thus do not ad-equately address the pathology. Thisoccurs when practitioners write or-thotic prescriptions with standard ormaximum arch fill or when orthoticlabs overfill the medial arch. In ef-fect, this choice is to ignore EBMand prescribe a less effective ortho-sis. This choice is a disservice to yourpatients and to the profession.

2) Follow EBM and prescribebetter orthoses but ship the or-thoses back to the lab when ad-justments are necessary. This isworkable, but a time-consuming,inconvenient, and expensive op-tion. On an online heel pain

forum, one patient, whosefeelings likely representthose of most patients,had this to say about herpodiatrist who followedthis scenario:

“My custom orthoticsare still uncomfortableafter four weeks.... I stillfeel like I have two golfballs shoved up under myarches. I made an appoint-ment with the podiatristwho made the mold. Ifthere are any adjustmentsthat need to be made, thenurse said they will needto be shipped back to thelab where the orthoticswere made; the podiatrist

is not going to make them. YIKES! Iam already perpetually in a state of‘waiting’ for relief. The turnaroundwill be at least two weeks. My ques-tion is... can I bring my orthotics toa local pedorthist and have modifi-cations made, or do they only workon their own fabrications? I am feel-ing a little panicky because I am ateacher, and I am hoping to get thisplantar fasciitis under control be-fore school starts. The idea of send-ing off my orthotic doesn’t soundlike a quick procedure.”

3) Follow EBM, prescribe betterorthoses, and develop orthotictroubleshooting and adjustmentskills.

4) Refer orthotic therapy to col-leagues who will follow EBM andprescribe more effective orthoses

EMB...

Continued on page 100

Figure 3: An orthosis made from a cast with mini-mum fill will conform closer to the arch of the footthan one made from a positive cast with standard ormaximum fill. (photo courtesy of LER, Recent Ad-vances in Orthotic Therapy, 2011)

more of an issue, but adjust-ing for size by grinding theorthosis narrower or the heelcup shallower are some of theeasier orthosis modifications.

• Ask your lab to glueyour covers “posterior only”.(Figure 6) This allows for easyadjustments to the distal por-tion of the orthosis, includ-ing the addition of modifica-tions such as metatarsal pads.

• Do not pre-scribe bottomcovers. Bottomcovers makemodificationsmuch more dif-

ficult to perform andcan be easily added tothe orthoses at a laterdate, once you and thepatient are sure the or-thosis is working as itshould.

Patient EducationWhen prescribing

more effective or-thoses that are notmade from positivecasts with excessivemedial arch fill, it iscritical that patientsunderstand ahead oftime that some adjust-ment may be neces-sary. When it is explained correctly,you will find that not only do theyunderstand, but they appreciatethat you are making a superior or-thosis for them. Let’s usemetatarsalgia as an example. Asnoted earlier, a number of recentstudies have demonstrated thatvery specific orthotic modificationsreduce pressure under themetatarsal heads.1-7 These includetotal contact orthoses (orthosesthat conform very close to the archof the foot), metatarsal pads, andcushioning under the met heads. Avery effective method to explainthe benefits of orthotic therapy,how your orthotics work better,and what problems patients mightexperience and how you will dealwith them is to explain the effectsof pressure on their feet. An expla-nation on orthotic choices for a pa-tient with metatarsalgia might golike this:

“In order to relieve your pain, a

and have the ability to modifythese devices in their offices.

Prescribing for ModifyingThe most common patient

complaint when prescribing EBMorthoses is an arch that feels toohigh. With some simple adjust-ments to your prescription, this isan exceedingly easy problem totroubleshoot effectively in the of-fice. These simple changes to yourprescriptions can make these ad-justments easy to perform:

• Prescribe Polypropylene or-thoses for a majority of your de-vices. Polypropylene is the easiestmaterial to adjust—especially whenarch irritation is present. Simply usea grinder to thin the planter surfaceof the arch of the orthosis (Figure 4)This increases the flex of the deviceand reduces orthotic reactive forceon the arch. It is a quick and easyadjustment. A video demonstratingthis technique can be seen atwww.tinyurl.OrthoticArch. Thearches on carbon fiber devices canalso be adjusted but require heatingthe device and lowering the arch.This is not only more time-consum-ing, but you run a significant chanceof altering the shape of the orthosis.

• Prescribe wider orthoses.Wider devices act to spread forceover a larger surface area, thus de-creasing the force applied persquare inch and decreasing the like-lihood of arch irritation (Figure 5).In addition, wider orthoses tend tooffer greater control over excessivepronation and arch collapse. Thedownside is that shoe fit may be

number of studies have shown thatwe have to reduce the pressureunder the ball of your foot. We dothis by putting an orthotic insideyour shoe that will transfer the pres-sure off of the ball of your foot andonto the arch. These studies showthat the tighter an orthotic hugsyour arch, and the wider it isthrough the arch, the more pressureit takes off the ball of your foot.”

Because of this, I need to adviseyou that in a smallnumber of cases, pa-tients may initially feelthe arch of the orthoticpushing too hard ontheir arch or they mayhave some problemswith shoe fit. If this oc-curs, it takes just a cou-ple of minutes to makean adjustment for youhere in the office, andwe always guaranteeyou will be comfortablein your orthotics. If Iwere to go the other di-rection and err towardorthotics that were toolow or too narrow, theymay never have achance to bother you,but they are also unlike-ly to provide you thebest pain relief.

In addition, you’llnotice that when you first get yourorthotics, the cover may not be

EMB...

Continued on page 102

100 www.podiatrym.comPODIATRY MANAGEMENT • MARCH 2011

Figure 4: A grinder is an essential tool for or-thotic practitioners. Among other uses, it can beused to thin the arch of the orthosis to increaseflex and reduce reactive force applied to theplantar aspect of the foot.

Figure 5: Wider orthosesspread weight over a largersurface area and are lesslikely to cause arch irrita-tion. This orthosis is the fullwidth of the foot.

Figure 6: Prescribing an orthosis withthe cover glued “posterior only” willmake it easy to add metatarsal pads andmake other adjustments to the anteriorportion of the orthosis. (photo courtesyof LER, Recent Advances in OrthoticTherapy, 2011)

(Non-toxic solvents such as Or-ange-Sol™ are very effective and safeto use)

• Korex to use for Mor-ton’s/reverse Morton’s extensions,varus/valgus extensions, aperture

• Poron to use for cushion• Self stick metatarsal pads• Self stick wedgesPodiatric medical supply houses

and orthotic labs can help you findnecessary equipment, materials andsupplies.

ConclusionAnecdotal evidence has always

existed to support the effectiveness of

custom foot orthoses in reducing footpain. Now, there is peer-reviewed sci-entific evidence to confirm not onlythe efficacy of orthotic therapy butalso how orthotic prescriptionsshould be written to best treat specif-ic pathologies. Studies demonstratingthe effectiveness of specific orthoticprescriptions are available for manypathologies including plantar fasci-itis, metatarsalgia, hallux limitus,adult acquired flat foot, rheumatoidarthritis foot, tarsal tunnel syndrome,and lateral ankle instability.

For individual podiatrists andthe profession of podiatricmedicine to maintain a reputationas experts and leaders in providingorthotic therapy, podiatrists mustprovide their patients with evi-dence-based orthotic therapy. To

glued down on the front. This is toallow me to easily make adjustmentsto your orthotics. Once you are surethey are working as they shouldwe’ll glue the cover down, and putvinyl on the bottom so that theyslide easily in and out of shoes.”

Orthotic Troubleshooting 101Unfortunately, most podiatric

medical schools and podiatric resi-dency programs spend little timeteaching orthotic troubleshootingtechniques. In addition, orthotictherapy, in general, and orthotictroubleshooting, in particular, arepoorly addressed at most podiatriccontinuing education programs. Ittherefore can be problematic for apractitioner to gain the trainingnecessary to become expert in or-thosis modifications. There are,however, at least a few good meth-ods to acquire this information:

1) Visit the offices of podiatristswho are experts at orthotic modifi-cations and troubleshooting.

2) Use orthotic labs which offerexpert consultation, including in-struction on orthotic modificationsand troubleshooting.

3) Attend seminars that incor-porate strong orthotic therapy com-ponent.

Basic Troubleshooting SkillsAt a minimum, every orthotic

practitioner who follows evidence-based orthotic therapy should beable to perform the following or-thotic modifications:

• Adjust for arch height/rigidity• Adjust for shoe fit, including

orthotic width and heel cup height• Add covers• Add metatarsal pads, metatarsal

bars, forefoot cushion, apertures,Morton’s extensions, reverse Mor-ton’s extensions, and varus/valguswedges.

Materials and EquipmentIn order to perform these basic

adjustments, some standard equip-ment and materials are needed.These include:

• Grinder• Ticro Polishing cone (to polish

polypropylene after grinding)• Hood or fume filter (Figure 7)• Solvent to remove covers

do so means that certain basic pro-ficiencies must be met. This in-cludes critical evaluation of footimage capture, whether by tradi-tional plaster methods or via opti-cal scanning; following evidence-based protocol in writing orthoticprescriptions and developing in-of-fice troubleshooting skills that willallow practitioners to alter orthosesto improve function and comfort.To ignore any of these proficienciesis to choose to provide patientswith orthoses that do not optimallyaddress their pathology. �

References1 Mueller MJ, Lott DJ, Hastings M.

Efficacy and mechanism of orthotic de-vices to unload metatarsal heads in peo-ple with diabetes and a history of plantarulcers. Phys Ther. 2006 Jun;86(6):833-42.

2 Chalmers AC, Busby C. Metatarsalgiaand rheumatoid arthritis—a randomized, sin-gle blind, sequential trial comparing 2 typesof foot orthoses and supportive shoes. JRheumatol. 2000 Jul;27(7):1643-7.

3 Kogler GF, Solomonidis SE, Paul JP:Biomechanics of longitudinal arch sup-port mechanisms in foot orthoses andtheir effect on plantar aponeurosis strain.Clin Biomech 11:243-251, 1996.

4 Kogler GF, Veer FB, Solomonidis SE,Paul JP. The influence of medial and later-al placement of orthotic wedges on load-ing of the plantar aponeurosis. J BoneJoint Surg Am. 1999 Oct;81(10):1403-13.

5 Roukis, et al. Position of the First rayand Motion of the First MTP. 1996JAPMA. Vol 86:11.

6 Harradine, Bevin: The Effect of Rear-foot Eversion on Maximal Hallux Dorsiflex-ion; 2000 J AmPodiatrMedAssoc, (90): 390.

7 McPoil, TG; Schmit, D. Compari-son of three methods used to obtain aneutral plaster foot impression. PhysTher. 1989 Jun;69(6):448-52.

8 Davis I, Laughton C, Williams, DSA comparison of four methods of obtain-ing a negative impression of the foot. Mc-Clay. J Am Podiatr Med Assoc. 2002May;92(5):261-8.

EMB...

102 www.podiatrym.comPODIATRY MANAGEMENT • MARCH 2011

Dr. Huppin is anadjunct associ-ate professor inthe Departmentof AppliedBiomechanics atthe CaliforniaSchool of Podi-atric Medicine atSamuel MerrittCollege. He isalso the medical director for ProLab Or-thotics and SHOES-n-FEET shoe stores.He has a private practice in Seattle, WA.

Figure 7: When working with glues, ahood or fume filter, such as this “FumeBuster” brand, are essential equipment.It functions as both a work surface anda fume filter.