therapeutic hosiery: an essential component of footwear for the

OCTOBER 2013 | PODIATRY MANAGEMENT | 155www.podiatrym.com

IntroductionThirty years ago, socks had the

same role as underwear in terms offunction and user benefit: they wereuniversally worn, yet ranked loweston the scale of importance in terms ofquality of life benefits.1 Today, spe-cialized socks (now known as thera-peutic hosiery) have evolved to be-come an important comfort item with

potential for significant medical bene-fits.2 The therapeutic hosiery categoryof footwear is now a $200 million in-dustry which is still in its infancy interms of product development and pa-tient utilization.

This article will review the historyof development of improved hosieryproducts for use in specific footpathologies. A review of published re-

search will be provided as well as acritical analysis of the current state ofthe art of therapeutic hosiery. It isclear that both consumers and clini-cians should be aware of the potentialbenefits of therapeutic hosiery. At thesame time, the buyers and prescribersof these products should be awarethat many of the benefits claimed by

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Objectives1) To review research rel-

evant to clinical benefits oftherapeutic hosiery.

2) To review the role ofpressure and shear reduc-tion provided by specializedhosiery products.

3) To review sock fibertechnologies with specificrecommendations for use intherapeutic hosiery.

4) To present newer socktechnologies which haveanti-microbial benefits, skinhydration benefits and im-proved cutaneous circula-tion benefits.

5) To designate specificpatient populations whowould benefit from regularuse of therapeutic hosiery.

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Following this article, an answer sheet and full set of instructions are provided (pg. 164).—Editor

Therapeutic Hosiery:An EssentialComponent

of Footwear for thePathologic FootSocks are an important element in the

treatment armamentarium.

BY DOUGLAS H. RICHIE JR., DPM

Therapeutic Hosiery:An EssentialComponent

of Footwear for thePathologic FootSocks are an important element in the

treatment armamentarium.

BY DOUGLAS H. RICHIE JR., DPM

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156 | OCTOBER 2013 | PODIATRY MANAGEMENT

manufacturers of therapeutichosiery are not substantiated by

valid research. Since these footwearproducts are not under FDA control,misleading marketing promotion ofhealth benefits of therapeutic hosieryproducts has led to confusion andmisunderstanding.

A review of research of benefits ofspecialized socks or hosiery will re-veal three primary areas of interest:plantar foot pressure reduction, re-duction of friction skin-shear injuries,and use of antimicrobial fibers in sockconstruction.

Plantar Pressure StudiesThe landmark studies document-

ing the pressure-relieving capability ofspecialized hosiery products weresupported by an athletic sock compa-ny (ThorLo®, Statesville, NC) who hadpatented a unique padded hosiery de-sign for sport application. These stud-ies on substantially padded athleticsocks revealed the potential therapeu-tic effects of hosiery products for spe-cialized patient populations with dia-betes, arthritis, and peripheral vascu-lar disease. For the first time, peer-re-viewed research was published inprestigious medical journals docu-menting potential benefits of hosieryfor foot pathologies.

The first study of pressure reliefof specialized padded hosiery wasconducted at the Manchester RoyalInfirmary in the United Kingdom.3

Veves, et al. measured plantar pres-sures in 27 neuropathic diabetic pa-tients while walking in a barefootcondition, while wearing their owntraditional socks, and while wearingpadded ThorLo hosiery. Compared tothe barefoot condition, the use of con-ventional socks provided no signifi-cant relief of plantar pressure. Whenwearing padded hosiery, a significant

26% reduction of peak plantar pres-sure was recorded. The researchersconcluded that specialized paddedhosiery could be a useful, acceptable,and inexpensive addition to existingmethods for protecting the insensitivefoot from abnormal pressures andloads.

In a subsequent study, Veves, etal. compared the pressure reduction

of experimental extra-padded hosierywith padded sport socks in the reduc-tion of plantar pressures in patientswith diabetic neuropathy.4 Both stylesof socks reduced plantar pressuressignificantly, although the extrapadded socks reduced pressures by31% compared to values of 17% and10% pressure reduction by ThorLosport socks. Of significance, the ex-perimental padded therapeutic sockscontinued to provide significant plan-tar pressure reduction of 17% aftersix months of continuous use.

In another study by Veves, et al.,the use of experimental extra-padded hosiery was studied in pa-

tients with rheumatoid arthritis.5

Often overlooked is the fact that therheumatoid foot can develop ex-treme plantar pressures due to re-stricted joint range of motion, atro-phy of the fat pad, and digital defor-mity. In this study, padded experi-mental hosiery was tested in 18 pa-tients with rheumatoid arthritis com-pared to the barefoot condition. Sig-

nificant reduction of plantar pres-sure (32%) was achieved whenwearing the padded socks comparedto barefoot walking. In addition,pain relief after wearing the paddedsocks for three months demonstrateda 51% reduction. This was the firststudy published in the literaturedocumenting that padded hosierycould relieve plantar pressures and

pain in the rheumatoid foot.Murray, et al. studied the patient

acceptability of extra-padded ThorLohosiery when worn with extra-depthshoes.6 A group of 86 neuropathicdiabetic patients were followed forsix months and completed satisfac-tion questionnaires at three and sixmonths. Evaluation scores weregood to very good in 85% of the pa-tients. The researchers concludedthat the comfort of padded hosierycould encourage improved compli-ance with appropriate footwear forprevention of ulceration in patientswith diabetes.

The previous cited studies of spe-cialized ThorLo hosiery were con-ducted on patients walking withoutshoes, and using the optical pedo-barograph to measure plantar footpressures. Thus, these studies weredirect comparisons of barefoot vs.socks without the influence of shoes.Flot, et al. were the first to measurein-shoe plantar pressure reduction ofpadded socks in the shoes of eighthealthy subjects.7 Significant reduc-tion of forefoot plantar pressures werenoted when wearing the paddedsocks compared to the control socks,although the pressure reductionswere not uniform across the entireforefoot.

Donaghue, et al. used in-shoepressure measurements to determinethe durability of padded ThorLo socks


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The researchers concluded that the comfortof padded hosiery could encourage improved compliance

with appropriate footwear for preventionof ulceration in patients with diabetes.

Often overlooked is the factthat the rheumatoid foot can develop extreme plantarpressures due to restricted joint range of motion,atrophy of the fat pad, and digital deformity.


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and extra depth shoes when worn by50 patients with diabetes and highrisk feet.8 Significant pressure relief(10.7%) was found with new shoesand padded socks, compared to cur-rent footwear. After six months ofcontinuous use, no loss of pressurereduction was determined with use ofextra-depth shoes and padded socks.The researchers concluded that therewas significant initial reduction ofplantar foot pressures when paddedsocks were worn with proper shoes,and this protective benefit was notlost after six months of continuoususe.

In addition to elevated plantarpressures, step shock has been associ-ated with tissue damage, which cancause ulceration on the weight bear-ing surfaces of the foot.9 Howarth andRome studied the shock attenuatingproperties of five different sock typeson a single subject while walkingover a treadmill.10 Acrylic cushion andwool cushion socks provided signifi-cantly increased shock attenuationcompared to cotton socks, cottonterry and cotton double layer socks.This verified previous observationsthat cotton fiber socks compress andlose shape during continuous wearcompared to synthetic acrylic fibersocks.

After this study, nearly ten yearspassed before any credible researchwas published in the medical litera-ture regarding protective benefits ofspecialized hosiery products. In themeantime, the therapeutic hosierysegment of the footwear industry un-derwent exponential growth as manymanufacturers introduced productswith proposed benefits for pathologicfeet, particularly the diabetic foot.None of these companies conductedpressure studies or other research tovalidate their marketing claims, yetusage of these products grew at an as-tronomical rate.

In 2005, Garrow, et al. studied 19patients with diabetes and peripheralneuropathy and compared a new dou-ble layer sock to ordinary socks to de-termine pressure relief in variousareas of the foot.11 A specialized dou-ble-layer hosiery product provided asignificant 9% reduction of in-shoetotal foot pressure compared to ordi-

nary “supermarket socks.” In addi-tion, a 14% reduction of peak forefootpressure and 8% increased surfacearea contact was achieved whenwearing specialized socks comparedto ordinary socks.

These pressure studies of special-ized hosiery products offer promise,but also provide results which requirecareful interpretation. While statisti-cally significant, the reduction of be-tween 10% and 32% peak plantarpressure may not have any influenceon the rate of ulceration in the diabet-ic patient.

Previous studies showing 25-32%reduction of plantar pressure withpadded hosiery were performed with-out shoes, while in-shoe studiesshowed much lower overall pressurereduction. While socks alone have ca-pacity to reduce damaging forces on

the soft tissue of the foot, their influ-ence is less significant than with ashoe alone or a shoe in combinationwith a custom-molded foot orthosis.

For example, Kastenbauer. et al.found that a 50% reduction of plantarpressure occurred when diabetic pa-tients wore running shoes with cus-tom-molded foot orthoses.12 However,a follow-up study showed that thispressure of an orthosis/shoe combi-nation will deteriorate over time, withonly a 13% reduction of pressure pro-vided at the end of one year.13 Black-well, et al. have shown that hosierywill show less noticeable pressure re-duction when worn in shoes com-pared to when worn in slippers.14

On the other hand, one couldargue that any pressure reduction inthe shoe of a diabetic patient with ahigh risk foot is better than no protec-tion at all. Since hosiery is an almostmandatory requirement of all people

wearing closed shoes, the up-grade to specialized hosiery repre-sents an acceptable, potentially cost-effective modification of lifestylewhich can protect the diabetic, at-riskfoot. Studies have shown that special-ized hosiery products can maintaintheir pressure relief over a period ofsix months or more, which is more fa-vorable than that seen with shoes andorthoses alone.

Shear StudiesFriction and shear are two other

major forces which are recognized tocontribute to the formation of ulcersin patients with diabetes.15

In gait, the human foot strikes theground from a tangential attitude,rather than a purely vertical orienta-tion. Friction is the active or staticforce that acts on the skin which re-

sists sliding. During walking, tangen-tial foot strike with the ground causesthe superficial skin to be subjected tofrictional force which then results inskin exfoliation and generation ofheat. A secondary shear force is thestatic situation where the fixed footexerts a horizontal (backwards) mo-tion against the deeper tissues duringpush-off, which results in blisteringand subsequent ulceration of the in-tegument.16

Only recently have devices beendeveloped to measure foot shear in-vivo. Lord and Hosien were able todetect a 15% reduction in shear be-neath the first metatarsal head whenthin nylon hosiery was comparedwith a barefoot condition.17 Other re-searchers have relied on a clinicalendpoint such as the formation offriction blisters to determine the effec-tiveness of hosiery products to reduce


While socks alone have capacityto reduce damaging forces on the soft tissue of the foot,

their influence is less significantthan with a shoe alone or a shoe in combination

with a custom-molded foot orthosis.

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shearing forces acting on thefoot during walking and running.Herring and Richie were among

the first to study the effects of hosieryfiber composition and construction onthe incidence of friction blisters inlong-distance runners. The first studycompared the incidence of blisters inrunners wearing special padded (ThorLo) socks either composed of 100%cotton fibers or 100% acrylic fibers.18

This was a longitudinal double-blindstudy of 35 long-distance runners.Cotton fiber socks were associatedwith twice as many blisters as acrylicfiber socks, and blister size was three-fold larger with the cotton socks. Therunners observed that the acrylic fibersocks kept their feet drier in a blindedanalysis.

The follow-up study repeated theoriginal design, but utilized genericsock construction, rather than paddedThorLo construction.19 The superiorityof acrylic fiber socks over cotton fibersocks could not be demonstratedwhen the socks were not padded. Theauthors concluded that the frictionreduction and wicking characteristicsof socks were dependent on bothfiber composition and constructiontechnique.

Friction blisters are among themost common foot injuries affectingthe athlete and are a serious threat ofdisability in the military.20 A studyperformed on 357 military recruits atParris Island, South Carolina revealeda 69% prevalence of blisters during afour-month period of training.20 Blis-ters serious enough to warrant medi-cal evaluation at sick-call occurred in24% of all trainees. An estimated5,000 basic trainees at Lackland Air-force Base were treated for frictionblisters during one calendar year in1990.21

Three studies have been publishedby the United States military involvingthe testing of sock systems to reducefriction/shear injuries in the feet. Inthe study of 357 military recruits, theuse of a Cool Max® liner with a heavilypadded wool/polypropylene outersock significantly reduced blisterscompared to a single-layer sock (40%vs. 69% frequency).20 When the CoolMax® liner was added to the singlelayer sock, sick call visits were re-

duced from 24% to 9%. In 1993, an-other study of 1,079 soldiers testedfive sock systems and blister frequen-cy.22 Synthetic fiber socks significant-ly outperformed the standard woolsock. Adding a Cool Max® liner signif-icantly reduced blisters. When com-paring single, extra-thick paddedacrylic socks to double layer socksystems, the double-layer systemswere superior presumably due toshielding of the terry loop construc-tion away from the skin and themovement interface which is avail-able in the double-layer construction.Jagoda also affirmed the superiorityof wearing a liner sock and paddedsock, compared to a single sock sys-tem in Marine recruits.23

Studies of socks and friction blis-ters on the feet suggest that the estab-

lishment of a movement interface ei-ther within the sock itself or betweenthe layers of a sock system will pre-vent skin injury. Furthermore, reduc-ing the friction force on the skin sur-face itself may be dependent upon thefiber composition of the sock, wheresynthetic fibers appear to work best.24

The superiority of certain fibersfor therapeutic hosiery are basedupon certain factors which relate toprotection from pressure and shear,reduction of moisture on the skin sur-face, resistance to compaction, andmaintenance of shape when subjectedto moisture and shear.

With regard to moisture manage-ment on the surface of the foot, theterms “hydrophobic” (repel moisture)and “hydrophilic” (retain moisture)are utilized in describing sock fiberperformance. In general, cotton fibersand most wool fibers are consideredhydrophilic, while synthetic fibers arehydrophobic. The response of socks

to exposure to moisture is importantfrom both a comfort and clinicalstandpoint.

Moisture can accumulate in theshoe of active people from three dif-ferent sources: the foot itself, the legsand trunk of the athlete, and the out-side environment. The foot containseccrine sweat glands which are inner-vated by cholinergic fibers activatedby the sympathetic nervous system.The palms and soles are unique inhaving the highest density of eccrinesweat glands in the body: 2000 glandsper square centimeter, compared to adensity of only 100 glands per squarecentimeter in the rest of the body.25

The production of moisture fromthe sweat glands of the feet duringvigorous physical activity is estimatedto be as much as 200 c.c per hour.26

The production of moisture from theremainder of the body during exercisecan exceed one liter per hour.26 Thesum total of moisture potentially col-lecting in the shoe of an athlete dur-ing exercise will quickly exceed theabsorptive capacity of any sock.Therefore, in order to keep moisturecontent at a minimal level on the sur-face of the foot during exercise, asock must “move” moisture away tothe shoe upper for evaporation. Thisprocess is known as wicking.27

Cotton fibers are hydrophilic andabsorb three times the moisture assynthetic acrylic fibers which arecommonly used in athletic hosiery.28

Once wet, cotton socks retain mois-ture and have a ten-fold greater dry-ing time compared to synthetic fibersocks.29 In sedentary activity, cottonsocks may be preferable to acrylicsocks, given the low moisture outputof the feet, and the fact that cotton


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Studies of socks and friction blisters on the feetsuggest that the establishment

of a movement interface either within the sock itselfor between the layers of a sock system

will prevent skin injury.


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socks can absorb this moisture with-out becoming saturated.

However, during vigorous activi-ty, the absorptive capacity of anysock will be exceeded, and only awicking gradient will allow move-ment of moisture from the foot sur-face to the shoe for evaporation to theoutside environment. Hydrophilicfibers such as cotton have a 2.4 timesgreater resistance to moisture trans-port.30 This may be related to absorp-tion of fluid and swelling within thefibers themselves. When wet, acrylicfibers swell 5% while wool fibersswell 35% and cotton fibers swell45%.31 Swelling of fibers is relatedalso to a loss of shape and conforma-bility to the foot. Cotton socks tend tobunch and elongate when wet, whilesynthetic fiber socks are more likelyto retain shape, cushion, and resilien-cy in these conditions.32

Moisture management is an im-portant function for therapeutichosiery. The coefficient of friction onthe skin surface is significantly in-creased by moisture.33 Increased fric-tion coefficient will result in greaterrisk of shear injury to the skin ordeeper tissues.34 This becomes impor-tant for patient populations with con-ditions of the feet which are accom-panied by fat pad atrophy, boneprominences, and structural deformi-ty. Increased moisture on the skinsurface of feet is associated withgreater risk of bacterial, fungal andviral infections.35

However, the primary patientpopulation at risk for skin injury is

the patient with diabetes and periph-eral neuropathy. Autonomic neuropa-thy causes a loss of innervation of theeccrine sweat glands of the feet, andsweating becomes absent. Thus, con-cerns about wicking and moisturemanagement by hosiery worn by thediabetic patient are irrelevant. On theother hand, the resilience, cushion

properties, and shear reducing prop-erties of synthetic fibers compared tocotton fibers should still be importantfactors in selection of socks for neuro-pathic patients.

Fiber Recommendations forTherapeutic Hosiery

A review of the medical literatureshows a clear superiority of syntheticfibers over cotton fibers in providing

health benefits for people with footpathology. These studies have docu-mented that acrylic fibers andpolypropylene fibers can provide bet-ter protection from impact, pressure,shear, and moisture accumulationcompared to cotton fibers. Yet, themedical marketplace continues to fea-ture “diabetic socks” composed ofcotton fibers. Many authorities andprofessional organizations continue toprovide consumer information to thegeneral public which includes thechoice of white cotton socks as beingpreferred for healthy feet.

This underscores a significantproblem for patients with at-risk feetwho seek information and products toprotect their feet. There is no regula-

tion of claims made by manufacturersof footwear and foot products sold tothe general public. These products aresold in retail pharmacies, departmentstores, home/health stores and, mostimportantly, over the Internet. A visitto any of these vendor outlets will re-veal a plethora of products and reme-dies for foot conditions which

promise therapeutic benefitswithout any scientific verification.Consumers continue to purchaseproducts which have no establishedbenefit, and which may pose signifi-cant threat to their foot health. Thenew exploding category of therapeutichosiery has more products with mis-leading advertising than any othertype of footwear marketed to patientswith at-risk feet.

Other Potential Benefits ofTherapeutic Hosiery

There has been recent attention tothe potential clinical benefit of com-pression in the upper of a sock wornby active people. In particular, someover-the-calf sport socks have enoughelastic compression to aid in venousreturn of blood flow from the feet andlower legs. Brown and Brown werethe first to show the benefits of ThorLo basketball socks in improving ob-jective and subjective measures in pa-tients with venous insufficiency.36 Aliet al. showed that over-the-calf sportsocks with specially designed uppersfor graduated compression would re-duce the symptoms of delayed musclesoreness in men after a 10 km roadrun.37 Graduated compression over-the-calf socks are now used in profes-sional hockey and by some worldclass distance runners. For many peo-ple, especially males, the option towear athletic-style socks to preventedema of the feet and ankles is pre-ferred over conventional compressionhosiery.

There are now several therapeutichosiery companies providing over-the-calf knitted socks which offer sub-stantial compression and potentialtherapeutic benefit. Peripheral edemais found in many patient populationswith lower extremity pathology.Edema causes fatigue, nerve entrap-


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The new exploding categoryof therapeutic hosiery has more products withmisleading advertising than any other type

of footwear marketed to patients with at-risk feet.

A review of the medical literature shows aclear superiority of synthetic fibers over cotton fibers

in providing health benefits for people with foot pathology.

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ment, stasis dermatitis and lim-ited joint range of motion. Reduc-

tion of peripheral edema has potentialbenefit for significant numbers of peo-ple over the age of 60. Yet, there con-tinues to be unsubstantiated concernabout the use of compression stock-ings for at-risk patient populations. Atmost, therapeutic socks will provide20 mmHg of pressure, which wouldnot occlude blood flow in any patientother than one with severe arterialobstruction.

Indications for TherapeuticHosiery

Most research published on theclinical benefits of therapeutic hosieryhas focused on pressure relief in thediabetic foot. Yet, many other patientpopulations would benefit from spe-cialized hosiery. Plantar pressure,skin shear, and pressure over boneprominences occur in many healthypeople who subsequently develop hy-perkeratosis, bursitis and friction blis-ters of the skin. Moisture accumula-tion on the surface of the skin of thefoot is associated with increased riskof bacterial and viral infection. Mois-ture will increase the coefficient offriction on the skin surface, renderingthe foot more vulnerable to blisteringand infection.

High plantar pressures are seen inpatients with rheumatoid arthritis aswell as healthy patients with cavusdeformity of the feet. Bone pressure,causing risk of skin injury, is seen insevere cases of hallux abductovalgusdeformity as well as severe claw toedeformity.

Patients with peripheral vasculardisease are at risk for skin injury ofthe feet and would be prime candi-dates for intervention with therapeu-tic hosiery. Venous insufficiency alsoincreases the risk of ulceration in thelower extremity, and specially de-signed therapeutic hosiery can protectthe skin of the lower legs and feetwhile providing significant compres-sion for relief of peripheral edema.

Finally, patients with generalizedfoot pain due to arthritis, fat pad atro-phy and bone prominences can ob-tain relief with padded hosiery. Elder-ly patients with these symptomsshould be prescribed specialized

hosiery to supplement footwear de-signed to protect the feet and providepain relief.

Fitting ConsiderationsWhile most podiatric physicians

are aware of the importance of shoefit in preventing foot pathology, fewappreciate the problems in findinghosiery which properly fit the foot ofthe patient. David Higgins*, a notedauthority in the design of therapeu-tic hosiery, has recommended that“the most fundamental and impor-tant elements of a proper therapeuticsock include optimal moisture man-agement materials, antibacterialfibers or treatments, and proper fitand design. As is true of anyfootwear designed for at-risk feet,proper fit should be consideredabove all else.”

Most health professionals are notaware that hosiery products are notsized specific to foot size: they are de-signed to span from three to foursizes. This leads to inappropriatestretching and thinning of the sockpadding when the larger end of the

size range is worn, and leads tobunching and wrinkling when theshorter end of the size range is worn.

Currently, most therapeutichosiery manufacturers use a sizingstandard based upon the National As-sociation of Hosiery Manufacturers(NAHM) with sizing boards to verifysock size. These standards are out-dated by today’s standards and thesesizing boards do not take into accountthe variations in circumference whichoccur in edematous, pathologic feet.Furthermore, most socks do not in-crease in width or circumference asthe size increases. Thus, larger feetautomatically have more stretchingand compression of the sock aroundthe foot.

The best therapeutic hosiery prod-ucts are sized to a maximum range oftwo shoe sizes. “Low end” hosieryproducts will offer two uni-sex sizesfrom Women’s size 6 to Men’s size13. This provides significant potentialfor improper fit, stretching, andbunching of sock material inside theshoe. Premium therapeutic hosiery of-fers at least four size ranges for menand women, with five ranges beingoptimal for both groups.

A fear of skin injury to the leg haspropagated a host of “non-binding”socks which actually may cause morerisk to the foot than properly fittedsocks which have adequate elasticfibers to maintain shape and support.Newer technologies are now availablein sock manufacturing which havevirtually eliminated toe seams andconstricting “bands” at the upper por-tion of the sock. Therapeutic hosieryshould conform to the foot with ade-quate composition of Lycra® or Span-dex®. These socks will not leave aseam or ridge line at the top of thesock, yet will maintain shape and re-sist migration into the shoe. Instead

of “non-binding” socks, the physicianshould recommend “non-bunching”socks which are elastic, conformingand supportive.

New Technologiesfor Therapeutic Hosiery

The most significant advance intherapeutic hosiery design over thepast ten years has been the introduc-tion of antimicrobial ingredients. So-called “hygienic fibers” have becomepopular in apparel, bedding, carpetingand hosiery. The appeal of this tech-nology is a perception of protectionfrom infection and odor when theseproducts are used or exposed to hu-mans. This provides far-reaching ben-


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Newer technologies are now availablein sock manufacturing which have virtually eliminated

toe seams and constricting“bands” at the upper portion of the sock.


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efits for the populations who utilizetherapeutic hosiery.

Silver is the first element to beutilized in hosiery products. Currentlyavailable under the brand name X-Static®, silver treated fibers have beenshown to be bacteriocidal and fungici-dal against most common strains ofmicrorganisms found on the feet ofhumans.38 Silver has long been recog-nized for its benefit in treatingwounds and continues to be a fa-vorite ingredient of newer high techwound dressings. Today, many com-panies offer socks composed of asmall percentage of X-Static® treatedfibers with proposed “anti-microbial”benefits for the user.

Another element with knownanti-microbial activity is copper.39,40

Copper sole socks utilizing a technol-ogy known as Cupron® have recentlybecome popular in the therapeutichosiery marketplace.41 The main med-ical claim made by copper sole dis-tributors is the anti-odor effects ofthese products.

Other anti-microbial chemicalshave been added to sock fibers whichare now being utilized in therapeutichosiery. One long standing compoundused in sock fibers is Microban®.42 Aswith silver and copper fiber socks,claims have been made in the market-ing of socks containing these anti-mi-crobial ingredients, but few of thebenefits have been substantiated withclinical studies. While there may beconsumer appeal about the ability ofthese socks to keep the skin of thefeet free of bacteria and fungus, nostudies have been published showingthis positive clinical outcome. At best,today’s anti-microbial socks will haveless tendency for odor. The develop-ment of socks which can prevent in-fection in the feet remains a goal forfuture research.

New fiber technologies haveshown, in preliminary studies, theability to increase the oxygen contentat the skin surface of the feet andlower extremities. Holofiber® is a newproprietary product which alters thenormal wavelength of visible lightand transmits this to the skin of theuser in the form of energy.43 A prelim-inary study conducted by LawrenceLavery, DPM showed a significant in-

crease in transcutaneous oxygen ofpatients with diabetes who woresocks composed of Holofiber®. A re-cently published double-blindprospective study showed that com-pression stockings with silver impreg-nated fibers caused a significant in-crease in transcutaneous oxygen per-fusion of the skin of the lower legcompared to regular hosiery.44

Nanotechnology is a new manu-facturing technique which imbeds mi-croscopic particles in fibers which can

be released on the surface of the skinfor potential therapeutic benefit. Anew patented technology known asthe Difoprev system (LVM Technol-gies, Bologna, Italy) consists of a sockloaded with microcapsules containingan active moisturizer. This system isdesigned to continuously hydrate theskin of the foot of the patient with dia-betes and autonomic neuropathy, thusreducing cracking, fissuring and hyper-keratosis. A recently publishedprospective controlled study showedthat this nanotechnology-designed, hy-drating sock system caused significantimprovement of skin health in patientswith diabetes.45 The authors speculatedthat this system could be an additionalpreventive measure for ulceration ofthe feet of patients with diabetes.

Summary and RecommendationsThe therapeutic hosiery market

has grown exponentially over the pastten years, but very little research hasbeen published relative to these prod-ucts after the initial pressure-reliefstudies were conducted by ThorLo inthe early 1990’s. As a result, most ofthe claims made by therapeutichosiery companies are not substanti-ated by clinical studies. These claimsinclude “non-binding” effects, anti-

microbial effects, and skin pro-tection benefits.

Based upon previous publishedresearch and current technologiesavailable in sock construction, the fol-lowing recommendations can bemade for the podiatric physician whoprescribes therapeutic hosiery:

1) The most credible research onclinical benefits of therapeutic hosieryhas focused on plantar pressure relief.The hosiery products showing signifi-cant benefit were constructed with

dense padding under the heel andforefoot areas of the foot.

2) Shearing injury to the skin ofthe foot has been speculated to bemore important than direct pressure.Double sock systems and heavilypadded socks have shown document-ed benefit in reducing skin shear in-juries of the foot.

3) Synthetic fiber socks are pre-ferred to natural cotton fiber socks foruse by patients with pathologic feet.Synthetic fibers offer superior mois-ture management, better resistance toshape deformation when wet, andbetter resilience compared to cottonfibers.

4) Therapeutic hosiery shouldcontain adequate elastic for con-formability, fit, and resistance towrinkling inside of the shoe. Fears of“binding” of the upper portion of thesock are unwarranted, given the newtechnologies to eliminate constrictivebanding at the top-line.

5) Newer anti-microbial sockfiber treatments have great consumerappeal but have yet to demonstrate,in published studies, any clinicalbenefits to the user. Still, addition ofthis technology to therapeutichosiery can only be a positive at-


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The therapeutic hosiery market has grown exponentiallyover the past ten years, but very little research

has been published relative to these products afterthe initial pressure-relief studies

were conducted by ThorLo in the early 1990’s.

www.podiatrym.com

FOOTWEAR

THERAPEUTIC HOSIERY


tribute to improve hygiene ofthe product itself.6) Therapeutic hosiery can have

benefits for patient populations withvenous insufficiency, when the upperof the sock covers the lower leg andhas adequate compression features.

7) Sock-fitting is critical to assurebenefit of padding and avoidance ofconstriction around key pressureareas. Newer therapeutic hosieryproducts are sized to a maximum oftwo size ranges. PM

*[email protected]

Bibliography1 Richie DH. Sock controversy. Phys

Sports Med. 1992: 20(5):55.2 Richie DH. Sports Socks: The role of

hosiery as an essential component offootwear for the active person. American JourMed Sports 2003.5:79-86.

3 Veves A, Masson EA, Fernando DJS, etal. Use of experimental padded hosiery to re-duce abnormal foot pressures in diabetic neu-ropathy. Diabetes Care. 1989;12:653-655.

4 Veves A, Masson E A, Fernando DJs, etal. Studies of experimental osieryin diabeticneuropathic patienets with high foot pres-sures. Diabet Med. 1990: 7: 324-326.

5 Veves A, Hay EM, Boulton AJM. Theuse of specially padded hosiery in the painfulrheumatoid foot. Foot 1992; 1: 175-177.

6 Murray HJ, Veves A, Young MJ, RichieDH, Boulton AJM. Role of experimental socksin the care of the high-risk diabetic foot. Amulticenter patient evaluation study. DiabetesCare. 1993; 16: 1190-1192,

7 Flot S, Hill V, Yamada W, et al. The ef-fect of padded hosiery in reducing forefootplantar pressures. Lower Extremity.1995;2:201-205.

8 Donaghue VM, Sarnow MR, Guirini JM,et al. Longitudinal in-shoe foot pressure reliefachieved by specially designed footwear inhigh risk diabetic patients. Diabetes Res ClinPract. 1996;31:109-114

9 Whittle MW: Generation and attenua-tion of transient impulsive forces beneath thefoot: a review. Gait Posture 10: 264-275, 1999.

10 Howarth SJ, Rome K. A short-termstudy of shock-attenuation in different socktypes. Foot 1996; 6: 5-9.

11 Garrow AP, van Schie CHM, BoultonAJM. Efficacy of multilayered hosiery in re-ducing in-shoe plantar pressure in high riskpatients with diabetes. Diabetes Care 2005,28: 2001-2006.

12 Kastenbauer T, Sokol G, Auinger M, Ir-sigler K: Running shoes for relief of plantarpressure in diabetic patients. Diabet Med 15:518-522, 1998.

13 Lobmann R, Kayser R, Kasten G, Kas-ten U et al: Effects of preventative footwearon foot pressure as determined by pedobarog-raphy in diabetic patients: a prospectivestudy. Diabet Med 18: 314-319.

14 Blackwell B, Aldridge R, Jacob S: Acomparison of plantar pressure in patientswith diabetic foot ulcers using differenthosiery. Int J Low Extrem Wounds 1: 174-178, 2002.

15 Boulton AM: Pressure and the diabeticfoot: clinical science and offloading tech-niques. Am J Surg 187: S17-S24, 2004.

16 Gere JM, Timoshenko SP: Mechanicsof Materials. 2nd ed. Boston, PWS Engineer-ing, 1990.

17 Lord M, Hosein R: A study of in-shoeplantar shear in patients with diabetic neu-ropathy. Clin Biomech 15: 278-283, 2000.

18 Herring KH, Richie DH. Friction blistersand sock fiber composition: a double blindstudy. J Am Podiatr Med Assoc. 1990;80:63-71.

19 Herring KH, Richie DH. Comparison ofcotton and acrylic socks using a generic cush-ion sole design for runners. J Am Podiatr MedAssoc. 1993;83:515-522.

20 Knapik JJ, Hamlet MP, Thompson KJ:Influence of boot-sock systems on frequencyand severity of foot blisters. MilataryMedicine 161 (10): 594-598, 1996.

21 Gackstetter G, Shrifter J: Injury reduc-tion sock study. Epidemiology Division, Lack-land Airf Force Base, 1994.

22 Robertson TW, Christopherson MS. Im-proved sock system customer test. Ligget, Ca:Fort Hunter, US Army Test and Experimenta-tion Command Center: 1994.

23 Jagoda A, Madden H, Hinson C. A fric-tion blister prevention study in a populationof marines. Mil Med. 1981;146:42-55.

24 Sanders JE, Greve JM, Mitchell SB, etal. Material properties of commonly used in-terface materials and their static coefficients offriction with skin and socks. J Rehabil ResDev. 1998;35:161-176

25 Kuno Y. Human Perspiration. Spring-field, IL: C.C. Thomas: 1956: 1-65.

26 Grice, K. Sweat glands and abnormali-ties of their function. In: Marks R, SammonPD, eds. Dermatology. Vol 6. New York, NY:Appleton-Century-Crofts; 1977:5-68.

27 Farnworth B: A numerical model of thecombined diffusion of heat and water vaporthrough clothing. Tex Res J 1986; 56: 653-65.

28 Product Knowledge Center for HighPerformance Fibers, Apparel and Gear. TheAcrylic council, Inc., 1285 Avenue of theAmericas, 35th Floor, New York, NY, 10019.

29 Euler RD. Creating “comfort” socks forthe U.S. consumer. Knitting Times. 1985;54:47.

30 Harris M. Handbook of Textile fibers.Washington, DC:Harris Research Laboratory,Inc; 1954: 173-189.

31 Physical Testing Laboratory: Moisture

absorbancy and transport of cotton versusacrylic half hose, Monsanto Textiles Compa-ny, Decatur, AL, 1988.

32 Textile Research Laboratory: High bulkOrlon: The best yarn for athletic socks,Progress Report, E.I. Du Pont De Nemours &Company, Inc, Wilmington, De, 1980.

33 Naylor PE. Experimental friction blis-ters. Br J Dermatol. 1955;67:327-335.

34 Sulzberger MD, Cortese TA, Fishman L,et al. Studies on blisters produced by friction.I. Results of linear rubbing and twisting tech-niques. J Invest Dermatol. 1966;47:456-463.

35 Levine N. Dermatologic aspects ofsports medicine. J Am Acad Dermatol.1980;3:415-423.

36 Brown JR, Brown AM. Nonprescrip-tion, padded, lightweight support socks in thetreatment of mild to moderate lower extremi-ty venous insufficiency. JAOA, 1995; 95:173-181.

37 Ali A, Caine MP, Snow BG. Graduatedcompression stockings: physiological and per-ceptual responses during and after exercise. JSports Sci 2007, 25: 413-419.

38 www.noblebiomaterials.com39 Grzybowski, J. and E. A. Trafny. 1999.

Antimicrobial properties of copper-coatedelectroconductive polyester fibers.Polim.Med. 29:27-33.

40 o Borkow, G., and Gabbay, J. (2005)Copper as a biocidal tool. Current MedicinalChemistry 12(18): 2163-75.

41 www.cupron.com42 www.microban.com43 www.holofiber.com44 Jaccard Y, Singer E, Degischer S, Imfeld

S et al. Effect of silver-threads-containingcompression stockings on the cutaneous mi-crocirculation: a double-blind, randomizedcross-over study. Clin Hemorheol Microcirc.2007: 36 (1): 65-73.

45 E. Banchellini, S. Macchiarini, V. Dini,L. Rizzo, A. Tedeschi, A. Scatena, C., Goretti,F. Campi, M. Romanelli and A.Piaggesi—Useof Nanotechnology-Designed Footsock in theManagement of Preulcerative Conditions inthe Diabetic Foot: Results of a Single, BlindRandomized Study—Volume 7 Number 2June 2008 page 82-87 in The InternationalJournal of Lower Extremity Wounds, SAGEPublications—USA.

Dr. Richie is an AdjunctAssociate Clinical Profes-sor in the Department ofApplied Biomechanics atthe California School ofPodiatric Medicine. He isa Fellow of the AmericanCollege of Foot andAnkle Surgeons and apast president of the

American Academy of Podiatric Sports Medicine.

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CME EXAMINATION

1) Relief of plantar pressure

with padded hosiery has shown

a reduction as high as _______

when compared to going bare-

foot.

A) 10%

B) 20%

C) 30%

D) 80%

2) Relief of plantar pressure,

inside of the shoe, provided by

padded hosiery, can be expected

on the order of:

A) 1%

B) 2%

C) 3%

D) 10%

3) Skin shear can occur during

walking gait, as a result of:

A) Plantar pressure

B) Tangential attitude of foot

strike

C) Unequal leg length

D) Neuropathy

4) Friction blisters of the feet

can be reduced by socks with:

A) Acrylic fibers

B) Cotton fibers

C) Thin padding

D) Over-the-calf design

5) Studies on marching soldiers

demonstrated significant reduc-

tion of blisters of the feet when

wearing:

A) Cotton socks

B) Gore-Tex socks

C) Copper sole socks

D) Double sock systems

6) Over-the-calf athletic socks

can:

A) Reduce symptoms of

venous insufficiency

B) Heal ulcers

C) Reduce bacteria

D) Prevent Achilles injuries

7) Therapeutic socks may not be

sized:

A) According to exact foot

size

B) According to circumfer-

ence of the foot

C) According to modern foot

measuring technique

D) All of the above

8) Cotton fiber socks

A) Absorb water better than

acrylic

B) Swell with water

absorption

C) Release moisture slowly

compared to acrylic

D) All of the above

9) Wicking describes the ability

of a sock fiber to:

A) Absorb moisture

B) Repel moisture

C) Move moisture along a

gradient

D) Attract heat

10) In terms of performance for

therapeutic hosiery, synthetic

fibers perform best in terms of:

A) Moisture management

B) Resistance to compaction

C) Wicking

D) All of the above

11) Reduction of shear and plan-

tar pressure are important for

patients with:

A) Diabetes

B) Rheumatioid arthritis

C) Hallux valgus

D) All of the above

12) All of the following are im-

portant characteristics of proper

therapeutic hosiery EXCEPT:

A) Padding

B) Conforming fit

C) Moisture management

D) One size fits all

13) The following are used as

anti-microbial additives for ther-

apeutic hosiery EXCEPT:

A) Copper

B) Silver

C) Microban

D) Aluminum

14) Anti-microbial fibers in

therapeutic socks can best be

expected to:

A) Prevent ulceration

B) Prevent skin infection

C) Prevent fungus toenail in-

fection

D) Prevent odor in the socks

15) Friction blisters of the feet

represent a classic

A) Shearing injury of the

skin

B) Ischemic injury of the

skin

C) Fungus infection

D) Viral infection


SEE ANSWER SHEET ON PAGE 165.


Continuing

Medical Education

Continued on page <None>

PM’sCPME Program

Welcome to the innovative Continuing EducationProgram brought to you by Podiatry ManagementMagazine. Our journal has been approved as asponsor of Continuing Medical Education by theCouncil on Podiatric Medical Education.

Now it’s even easier and more convenient toenroll in PM’s CE program!

You can now enroll at any time during the yearand submit eligible exams at any time during yourenrollment period.

PM enrollees are entitled to submit ten examspublished during their consecutive, twelve–monthenrollment period. Your enrollment period beginswith the month payment is received. For example,if your payment is received on September 1, 2006,your enrollment is valid through August 31, 2007.

If you’re not enrolled, you may also submit anyexam(s) published in PM magazine within the pasttwelve months. CME articles and examinationquestions from past issues of Podiatry Manage-ment can be found on the Internet athttp://www.podiatrym.com/cme. Each lesson isapproved for 1.5 hours continuing education con-tact hours. Please read the testing, grading and pay-ment instructions to decide which method of par-ticipation is best for you.

Please call (631) 563-1604 if you have any ques-tions. A personal operator will be happy to assist you.

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The Podiatry Management Magazine CMEprogram is approved by the Council on PodiatricEducation in all states where credits in instructionalmedia are accepted. This article is approved for1.5 Continuing Education Contact Hours (or 0.15CEU’s) for each examination successfully completed.

Home Study CME credits nowaccepted in Pennsylvania

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CME EXAMINATION

www.podiatrym.com164 | OCTOBER 2013 | PODIATRY MANAGEMENT

16) Increased moisture content on the skin of

the feet is associated with all of the following

EXCEPT:

A) Increased coefficient of friction

B) Risk of bacterial infection

C) Risk of viral infection

D) Peripheral edema

17) Diabetic neuropathy is associated with:

A) Hyperhydrosis

B) Anhydrosis

C) Spasiticy

D) Clonus

18) Padding in hosiery can be beneficial to

patients with all of the following EXCEPT:

A) Cavus foot deformity

B) Rheumatioid foot deformity

C) Prominent plantar metatarsal head

D) All of the above

19) Therapeutic hosiery products:

A) Are FDA-controlled

B) Promote only scientific proven clinical

benefits

C) Have potential for significant patient

benefit

D) Are sized exactly to matching shoe size

20) The most important clinical benefit of ther-

apeutic hosiery, as documented by published

medical research, is

A) Relief of plantar pressures

B) Non-binding relief

C) Prevention of infection

D) Prevention of ulceration

See answer sheet on page 165.

Please print clearly...Certificate will be issued from information below.

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rolled in the annual exam CPME program, and we receive this examduring your current enrollment period. If you are not enrolled, pleasesend $22.00 per exam, or $169 to cover all 10 exams (thus saving $51over the cost of 10 individual exam fees).

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�

ENROLLMENT FORM & ANSWER SHEET (continued)Co

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Medical Education Lesson Evaluation

Strongly Stronglyagree Agree Neutral Disagree disagree

[5] [4] [3] [2] [1]

1) This CME lesson was helpful to my practice ____

2) The educational objectives were accomplished ____

3) I will apply the knowledge I learned from this lesson ____

4) I will makes changes in my practice behavior based on thislesson ____

5) This lesson presented quality information with adequatecurrent references ____

How long did it take you to complete this lesson?

______hour ______minutes

What topics would you like to see in future CME lessons ?

Please list :

__________________________________________________

__________________________________________________

__________________________________________________

__________________________________________________

__________________________________________________

__________________________________________________

__________________________________________________

1. A B C D

2. A B C D

3. A B C D

4. A B C D

5. A B C D

6. A B C D

7. A B C D

8. A B C D

9. A B C D

10. A B C D

11. A B C D

12. A B C D

13. A B C D

14. A B C D

15. A B C D

16. A B C D

17. A B C D

18. A B C D

19. A B C D

20. A B C D

Circle:

EXAM #7/13Therapeutic Hosiery: An Essential Component

of Footwear for the Pathologic Foot(Richie)

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therapeutic hosiery: an essential component of footwear for the

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