IN'i't:RNATIONAI. JOIIKNAI. OF LFPROSY^

Volume 70, Nui»her I/'riirlc'(/ in lhe U.S.A.

(ISSN 0148-016X)

The Paper Grip Test for Screening on Intrinsic MuscleParalysis in the Foot of Leprosy Patients'

Maartje M. L. de Win, Wim J. Theuvenet, Paul W. Roche,Rob A. de Bie, and Henk van Mameren 2

Foot problems are one of the most com-nmon causes of `dehabilitation' and morbid-ity in leprosy. Mostly, there is a combina-tion of sensory, motor and autonomic nerveaffection resulting in progressive loss ofprotective sensation, weakness and muscleatrophy ( 12 ). Approximately 10% to 15% ofleprosy patients have impairments and dis-abilities involving their feet, especiallyplantar ulceration, drop-feet, claw feet andtarsal disorganization (23 ). Recurrent ulcera-tion, in spite of protective footwear, is themost frequent indication for admission inLeprosy hospitais.

Although much attention is given toanesthesia of the foot sole as a cause offoot problems in leprosy and other neu-ropathies of the foot, less attention is givento paralysis of the intrinsic muscles. How-ever, it is thought that anesthetic feet with-out intrinsic muscle paralysis are not proneto ulceration ( 24 ). As paralysis of the intrin-sic muscles of the hand leads to clawhands, paralysis of the plantar intrinsicmusculature of the foot leads to claw toes( 12 ). Intrinsic muscles contributo to the ar-chitecture of the longitudinal and trans-verse arches of the foot, which aid in thedistribution of mechanical stresses, espe-cially during walking (3, 19. 20 ) . Paralysiswill lead to abnormal foot structure and in-creased peak-loads. Clawing of the toesdue to intrinsic muscle paralysis alsocauses a shift in distai direction of the

' Received for publication on 1 February 2001. Ac-cepted for publication on 7 February 2002.

2 M. M. L. de Win, M.D.; H. van Mameren, M.D..Ph.D.; Department of Anatomy and Embryology,Maastricht University, P.O. Box 616, 6200 MD, Maas-tricht, The Netherlands; W. J. Theuvenet, M.D.. De-partment of Plastic and Reconstructive Surgery, GelreHospitais, P.O. Box 9014, 7300 DS, Apeldoorn, TheNetherlands; P. W. Roche, Ph.D., Mycobacterium Re-search Laboratory, The Leprosy Mission, Anandaban,Nepal; R. A. de Bie, Ph.D., Department of Epidemiol-ogy, Maastricht University, The Netherlands.

Reprint requests to M. M. L. de Win at the aboveaddress.

plantar fat pad below the metatarsopha-langeal (MTP) joint, exposing the thinnerpart of the skin to pressure ( 7 ). Therefore,additional intrinsic muscle paralysis in-creases the risk of ulceration in anestheticfeet by a factor of 10 to 12 ( 23 ). The com-bination of anesthesia and paralysis isfound in 85% of ali ulcers; the majority islocated in the forefoot, especially in theMTP joint region (x' 23 ). lnfectious condi-tions, like osteomyelitis, septic arthritisand septic tendosynovitis are most com-mon complicating factors causing furtherdeformation (").

In the early stage of intrinsic muscleparalysis, education, sel f-care and specialfootwear can help in preventing further de-formities (4 . ' S. 2'' 22 ) . Moreover, claw toe de-formity and its consequences may be pre-vented and corrected by tendon transfersurgery, employing the long flexor of eachdigit. This procedure is only possible intiexible claw toe deformities and is prefer-able to procederes used for fixed claw toedeformities (arthrodesis with or withoutshortening of the toe) because it provides apartia! restoration of function ( 13 ). Thus, justas with the early detection of sensibilityloss, the early detection of intrinsic muscleparalysis has important implications for theprevention of impairment and deformity. Inspite of this, there is no reliable manual testthat can be used as a screening test for in-trinsic muscle strength in leprosy patients,un 1 i ke the routine tests that are done for theexamination of the extrinsic muscles or thesensibility of the foot.

The lack of a reliable screening test gaverise to the development of the Paper GripTest (PGT) by W. J. Theuvenet and P. W.Roche from The Anandaban Leprosy Hos-pital, The Leprosy Mission, Nepal, in 1990.This PGT can be used as a screening test forplantar intrinsic foot muscle paralysis. ThePGT resembles the Froment test for detec-tion of intrinsic hand muscle paralysis,

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Photograph: The Paper Cirip Test of the great toe(PGTI ). A paper siip is put under the great toe just dis-tal to the MTP joint. While the examiner tries to pullthe paper away, the patient offers maximal resistance.lhe hand of the examiner rests at patients' knee assur-ing the heel is kept on the Iloor.

where the patient has to hold a piece of pa-per between the pulp of the thumb and thatof the index finger while the examiner triesto pull it away ( 25 ). This test becomes posi-tive when the adductor pollicis, the firstdorsal and the second palmar interosseimuscles are paralyzed, because the patient,in an effort to hold on to the sheet, will flexthe distal phalanx of the thumb before los-ing grip of the paper. In the PGT for the hal-lux, the patient will try to hold a piece ofpaper pressed between the pulp of the bigtoe and the floor, while the examiner tries topull it away. If the flexor hallucis brevis isparalyzed, the patient will fiex the distalphalanx of the hallux before loosing grip ofthe paper.

The purpose of this study was to investi-gate the reliability of the PGT as a screen-ing test for intrinsic muscle weakness of thefoot. We investigated the outcome of thePGT in leprosy patients compared to non-leprosy controls. Also, the correlations be-tween the outcome of the PGTs and dilTer-ent factors, such as foot sole sensibility,gender, age and type of leprosy were objec-tives of this study.

MATERIALS AND METHODSThe Paper Grip Test. Two variants of

the PGT were conducted, PGT 1 to detectintrinsic muscle weakness of the great toeand PGT2 to detect weakness of the com-bined intrinsic muscles of the lesser toes(second, third , fourth and tifth toe).

During the test, the person (footwear anelsocks removed) sits up straight with hips,knees and ankles in 90° of tlexion. The ex-aminer insures that the patients stay in thesame position and keep their heels on thefloor during the test. The patients have tolook at their feet, because leprosy patientswith anesthetic feet will not feel the paper,causing difficulty in holding the paper.

The examiner puts a slip of strong roughpaper under the phalanges of the great toe(for the PGT 1) or the four lesser toes (forthe PGT2), respectively, just distal to theMTPjoints (see photograph). The examinerpulls the paper away with gradually in-creasing power in a horizontal direction,while the patient offers resistance. In ali ex-aminations, solid rough paper (2 x 10 cm,100 g/m 2 type) that did not easily tear, and asmooth underground of concrete was used.

The PGT was performed up to threetimes when the patient was not able to gripthe paper. The PGT was considered positive(abnormal) when it was possible to easilypull the strip away ali three times. The testwas considered negative (normal) when thepatient was able to grip the paper at leastone out of three times.

Patients and controls. In 1998, during aperiod of four months, leprosy patients(new patients and patients who carne forfollow-up) and non-leprosy subjects fromthe Purulia Leprosy Home and Hospital(The Leprosy Mission. Purulia, West Ben-gal, India) were examined for their intrinsicmuscle function. Patients with paralysis ofthe long flexors and extensors of the toes,

1 K^ International .Iourncll oJ Lepi o,s v^2002

infective ulceration, rigid claw toes or othergross deformities were excluded. Patientswith small non-infected ulcerations werenot excluded. The non-leprosy suhjectswere volunteers without foot deformities,selected from the same background (familymembers of the patients and personsmatched for social standing) in order to pre-vent pias due to different types of feet andfootwear.

Five hundred seventeen leprosy patientsand 170 non - leprosy controls met the inclu-sion criteria. Information about age (<20,20-39, 40-59 and >59) and type of leprosy(TT = tuberculoid leprosy, BT = borderlinetuberculoid leprosy, BB = borderline lep-rosy, BL = borderline lepromatous leprosy,LL = lepromatous leprosy, PN = pure neu-ropathic leprosy) was obtained of each per-sou. The proportion of males was 67.4% inthe leprosy group and 66.5% in the controlgroup. A majority of males correspondswith the general gender-distribution of lep-rosy ( "). The mean age was 30.3 years in arange from 4 years to 81 years old. Of those517 leprosy patients, 496 met the criteriafor both feet and 21 patients met the criteriafor only one foot, so a total of 1013 leprosyfeet were included in the study. The resultsof these 21 patients were only regarded inthe analysis of the relation between out-come of the PGT and foot' sole sensibility.The other analysis required both feet to beincluded (N = 496).

Extrinsic muscle testing. The functionsof the tibialis anterior, the extensor digito-rum longus, the extensor hallucis longus,the flexor digitorum longus, and the flexorhallucis longus were tested by means of iso-metric contraction against resistance in un-loaded feet ( 6). For testing of the tibialis an-terior, extensor digitorum longus and theextensor hallucis longus, the patient had tomove his feet and toes dorsally, while theexaminer offered resistance to the extensionof the toe and fixed the ankle at 90° of flex-ion. For testing the flexor digitorum longusand flexor hallucis longus the patient movedhis toes plantarwards, while the examineroffered resistance to the distal phalangesand fixed the proximal phalanges in a flexedposition to relax the intrinsic muscles.

Sensibility testing. Sensibility of the footsole was tested by means of a 10 graniSemmes-Weinstein monofilament ( 5 ). Thishas been described to be a reproducible

method for detecting loss of protective sen-sation of the sole of the foot ("). After ade-duate explanation and demonstration, sensi-bility was tested at three regions: the firstmetatarsal head (medial plantar - nerve), thefi fth metatarsal head (lateral plantar nerve),and the heel pad (tibial nerve). The exam-iner gave a stimulus up to three times ateach region. Sensibility was regarded asnormal when a patient was able to indicateall three regions of pressure stimulus witheyes closed at least one out of three timestested. A foot was regarded partially anes-thetic when the patient was able at least onceto indicate the pressure stimulus at either oneor two an regions and as totally anestheticwhen the patient was not able to indicate thepressure at any of the three regions.

Exanniners. To d i mi n ish i nformationbias, two examiners performed the exami-nation. The first examiner determinedwhether patients and controls met the inclu-sion criteria. This examiner also determinedthe function of the plantar intrinsic musclesof the foot by means of the PGT 1 and PGT2.The second examiner, a hospital staff phys-iotechnician, performed sensibility testing ofthe sole of the foot as part of a three-monthroutine check up for leprosy patients. Athird examiner was involved to measure thei nter-observer variahi lity of the PGT.

Validity and reliability of the PaperGrip Test (PGT). In 7 leprosy patients withloss of protective sensation of the forefootbut normal PGT1 and 7 non - leprosy sub-jects with normal PGT 1, an experiment wasdone to test the validity of the PGT in deter-mining plantar intrinsic muscle paralysis ofthe foot. In all 14 persons, the tibial nerveof one foot was artificially blocked by in-jecting 5 cc bupivacaine l % inside thetarsal tunnel. After the in,jection, the PGT 1testing was repeated.

In three healthy persons, we tested the ac-tivation of the plantar intrinsic muscles andlong muscles of foot and toes, while per-forming the PGT1 by means of surfaceelectromyography.

Inter- and intra-observer reliability wasdetermined on the basis of the results of theexaminations of 20 leprosy patients (N = 40feet) independently by the first and third ex-aminer, alternateiy just after each other.I ntra-observer vari abi l ity was determinedby examining 43 leprosy patients (N = 86feet) twice by the same examiner on two

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C7 both feet abnormal ^ one foot abnormal ^ both leal normal

Fic. 1. Positive PGTI of the great toes and PGT2of the lesser toes in leprosy patients and non-leprosycontrols. Numbers in lhe columns present ahsolutenumhers of persons.

separate occasions with an interval of ap-proximately three months.

Data analysis. The bivariate Pearsoncorrelation-analysis was used to detect lin-ear relations between outcomes of the PGTsand leprosy, foot sole sensibility, gender,age and type of leprosy. Through this analy-sis it is possible to present the relation be-tween two variables, correcting it for othervariables by means of the partia] correlationcoefficient (pcc). A p-value <0.05 was re-garded as signilicant ( 1 ).

An agreement in inter- and intra-observerexaminations was analyzed separately forPGT 1 and PGT2 through the non-weightedCohen's kappa coefficient (x-value) for twocategories (either PGT positive or PGTnegative) (2).

RESULTSPGT in leprosy patients and controls,

specificity of the PGT. Figure 1 showsthat 35.9% of the leprosy patients (N =496) had a positive PGT 1 and 49.6°I, had apositive PGT2 of one or both great toes. Incomparison, in the control group (N =170), 7.1% had a positive PGT1 and17.6% a positive PGT2 of one or bothgreat toes. Corrected for gender and age,significantly more leprosy patients thannon-leprosy controls had a positive test(pcc = 0.29 and p <0.01 for both PGT1 andPGT2).

Positive tests in the control group can beregarded as false positive tests, so from

PGT1 and PGT2 abnormal^ PGT1 or PGT2 abnormal^ PGT1 and PGT2 normal

Fio. 2. Positive PGTI of the great toes and PGT2of the lesser toes in the feet (n = 1013) of leprosy pa-tients with dilferent leveis of foot sole anesthesia; nor-mal sensibility (n = 606), partia) anesthesia (n = 211),total anesthesia (n = 196). Numbers in the columnspresent absoluto numhers of leal.

these results specificity can be calculated.Sixteen (2 x 4 + 8) false-positive results in340 tested feet give a specificity of 95.3%for PGTI, and 47 (2 x 7 + 13) false-positiveresults in 340 tested feet give a specificityof 86.2% for PGT2.

Infiuence of sensory loss, gender, ageand leprosy type on the outcome of thePGT. To examine the relation between apositive PGT and loss of foot sole sensibil-ity, ali the feet of leprosy-affected peoplewere regarded separately. These weredivided roto three groups according to thedegree of sensibility loss of the foot sole.Figure 2 shows that 71.3% of the totalanesthetic feet had a positive PGT of bothgreat and lesser toes (positive PGT1 andpositive PGT2). In the group of pardalanesthetic feet 33.2% had a positive PGTIand a positive PGT2, while 25.6% showedeither PGTI- or PGT2-positive. Leprosyfeet with a normal sensibility showed apositive PGTI and/or positive PGT2 in24.8%. The relation between the degree ofsensibility loss and a positive PGT provesto be significant correlated after correctionfor gender, age and type of leprosy (pcc =0.49, p <0.01).

The presentation of a positive PGT testamong males and females in both leprosyand non-leprosy groups is shown in Figure

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International JOurnal of .. L('l)msv^ 2002

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PGT1 of one or both great toes abnormal

L7 PGT1 of both great toes normal

FIG. .. Positive PGT 1 of the great toes in malesand females in hoth Ieprosy patients (n = 496) andnon-Ieprosy controls (n = 170). Nuinhers in thecolumns present ahsolute nunnhers of persons.

3. Female leprosy patients turned out tohave a higher prevalence of a positive PGTof one or both great toes (46.0%) than inaleleprosy patients (31.0%). After correctionfor age and type of leprosy this relationproved to be sign i fi cant (pcc = 0.21, p<0.01). In the non-leprosy group there val-ues were 14.0% for females and 3.5% formales (pcc = 0.24, p <0.01).

Figure 4 shows that the prevalence of apositive PGT increases with older age.PGT1 was positive in 49.5% of leprosy pa-tients in the age group 40-59, against21.0% positive tests in the age group up to19. After correction for gender and type ofleprosy the relation between a positivePGT1 and age proves to be sign i ficant forboth leprosy group (pcc = 0.22, p <0.01)and control group (pcc = 0.19, p = 0.01).

The distribution of a positive PGT amongdifferent types of leprosy is shown in Fig-ure 5. The percentages of patients with pos-itive PGT I of one or both feet varies signif-icantly per type of leprosy after correctionfor gender and age (pcc = 0.16, p <0.01).The highest percentages of a positive PGTwere found among patients with PN-, BB-and LL-type of leprosy. A positive PGT1 inTT-type of leprosy (14.3%) is two timeshigher than in non - leprosy patients (7.1%,Fig. 1).

Validity and reliability of the PaperGrip Test. In both leprosy patients andnon - leprosy subjects the PGT1 changed

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FIG. 4. Positive PGT I of the great toes in If erentage groups in Ieprosy patients and non-leprosy con-trols. Nunihers in the col u nins present ahsolute nunm-hers of I)ersons.

from negative (normal) to positive (abnor-mal) in ali 14 feet tested, after blocking thetibial nerve incide the tarsal tunnel with 5 ccbupivacaïne 1%. The long flexors of thefoot and toes remained unaffected.

Electromyography in theee healthy per-sons conformed that the plantar intrinsicmuscles were used in testing with the PGT.However, also long flexors of the foot andtoes showed electromyographie activity.

The K-value for the inter-observer reli-ability (non-weighted, 2 categories, N = 40feet) is calculated at 0.87 195% Cl;0.69-1.04] for PGT1 and 0.61 [95% CI:0.34-0.87] for PGT2. The K-value for theintra-observer reliability (non-weighted, 2categories, N = 86 feet) is calculated at 0.56195% CI; 0.36-0.76] for both PGT1 and0.56 [95% CI: 0.39-0.74] for PGT2.

DISCUSSIONValidity, specificity and reliability of

the PGT. The results of the experiment, be-fore and after the block of the tibial nerve atthe levei of the tarsal tunnel (not affectingthe long flexors and extensors of foot andtoes), show that the PGT1 is capable of se-lectively demonstrating intrinsic foot mus-ele weakness. The EMG experiment showsthat the extrinsic mescles were also acti-vated during the PGT but, by assuring nor-mal strength of the long flexors in ali oursubjects, there was no difference betweenour subjects regarding extrinsic musclefunction.

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FIG. 5. Positive PGTI of the great toes in differenttypes of leprosy. Numbers in lhe columns present ah-solute numbeis of persons.

The speciiicity of 95.3% for PGTI foundin this study can be considered high ascompared to that of other manual musclestrength tests ( 16). There is a lower speci-ficity of PGT2 (86.2%) than PGT 1. To pre-veni many false-positive results the PGTIis probably a better screening method to de-teci intrinsic muscle weakness than thePGT2. However, the two tests do not pro-vide identical infornmation, so another pos-sibility, explaining the higher percentagesof positive PGT2 as opposed to the PGT 1of the leprosy group, is that the lateral plan-tar nerve is more often affected by leprosythan the medial plantar verve.

The inter-observer agreement can be re-garded as good for PGTI and moderate/goodfor the PGT2. This is comparable to the in-tertester reliability of other manual musclestrength testing used in leprosy (` 1 ), but thenumber of patients was small. The intra-observer reliability is moderate for bothPGTI and PGT2 ( 2). When the moderate xvalue really reflects the intra-reliability ofthe PGT, this is a relativo weakness of thePGT. However, the moderate reproducibil-ity may also be caused by actual changes inmuscle function during the long interval be-tween the first and second measurement(approximately three months). Especially inthe beginning phase of multidrug therapynerve reactions that cause changes in mus-cle function may occur.

The correlation that we found betweenboth age and type of leprosy and positive

PGTs is similar to the correlation betweenseveral disabi1ides, baseei on peripheralnerves affection and age and type of leprosydescribed in other studies ( 10 15).

The use of the PGT as a screening testfor intrinsic muscle paralysis of the foot.The PGT can be a valuable addition to thephysical examination of leprosy out-patients. It is a simple, cheap and non-invasive test that does not require additionalequipmcnt. These properties make the testespecially suitable for screening on thefunction orplantar intrinsic foot muscles inleprosy patients in hospitais and duringfieldwork in developing countries.

From our results we conclude that thescreening of leprosy patients with the PGTsin addition to the sensibility testing is veryimportant. First, because we have foundthat the intrinsic muscles of the great toe areaffected in more than one-third of the lep-rosy patients without gross deformities.Second, because many partially anestheticfeet appeared to have intrinsic muscleweakness. Third, in this study intrinsicmuscle weakness of both great and lessertoes is found in more than 70% of the totalanesthetic feet, making them especially vul-nerable to ulceration. On the other hand,15% of the patients with total anestheticfeet have strong intrinsic muscles makingthem less vulnerable to ulceration ( 24). Thelong-term care of these patients could belimited to regular control of the skin of thefoot and the usage of protective footwear.Late development of plantar paralysis, longafter cure of the disease, is quite rare.Fourth, because the PGT may give earlywarning of nerve function impairment inpatients with intact foot sole sensibility asmeasured by the 10 grani mono lilamentmethod.

Clinica) consequences of a positivePGT—prevention of foot deformity.When impaired intrinsic muscle function ofthe foot is detected by means of the PGTscreening method, this has important clini-cai consequences. An early sign of the lossof intrinsic muscle function deserves thesame treatment as, for instance, signs of ul-nar nerve neuritis. Apart from the attempt totreat the neuritis, e.g., with corticosteroids,other measures to preveni deformity of thefoot are necessary. When a patient lias apositive PGT, a Harris mal print can beused, if available, to detect changes in the

22^ Inte> itaiional .Iournal of' Lehmsy^ 2002

weight beari ng areas (x) as an i ndication toadapt the footwear. For example, specialprotection especial ly of the metatarsal ^lreacan he created by the provision of a rig idsole, which will preveni stress to themetatarsal pads during the push-off phaseof walking. In a flat terrais a rocker i»echa-nism can also be considered. The imoleshould provide support to the longitudinalarch by an arch-support, to the transversearch and the metatarsal heads hy a metatarsalbutton, and it should add stahility to the heelwith a heel cup. Signs ofcollapse of the lon-gitudinal arch can be detected by measuringa decreasing projection height of the medialmal leol us of the weight beari n g foot. In anearly stage of claw toes, when the toes arestill mobile, a tendon transfer is possible toprevent further clawing of the toes ( 1 z).

Limitations of the PGT and recom-mendations for iniprovement. The lack ofanother reliable, non-invasive clinicai testthat measures intrinsic muscle strength withwhich the PGT could be compared, is a lim-itation of this research. Because we couldnot compare the PGT to another test, it wasnot possible to assess the sensitivity of thePGT. The only reliable gold standard wouldbe needle electromyography, which we didnot use in this study. Surface electromyog-raphy showed not only electromyographicactivity in the intrinsic muscles, but also inthe long muscles of the toes. But, by assur-ing normal strength of the long flexors in aliour subjects, a positive PGT caused byweak extrinsic muscles is excluded.

The first examiner performed the lnclu-sion of patients and PGTs so the outcome ofthe PGTs was potentially vulnerable to infor-mation bias due to a knowledge of variablesas leprosy/non-leprosy and type of leprosy.During examination of the foot this exam-iner also became aware of ulcerations of thefoot. This bias was limited hy emphasizingthat ali subjects should give as much pres-sure to the paper slice as they possibly could.

False-positive PGTs may generally becaused by weak muscle power and/or a per-son's misunderstanding of the test proce-dure. This may also expiais the higher per-centages of positive PGTs in older peopleand females in hoth the leprosy and thecontrol groups. Moreover, females wereless inclined to give firm resistance with theirfeet in reaction to the pulling of the paper.

A relatively high proportion of feet fromleprosy-affected persons with no loss ofplantar sensibi 1 ity was fou nd to have posi-tive PGTs (PGT 1 10.7%, PGT2 23.1%).Partially Chis could he explained hy false-positive results of the PGTs, but in the con-trol group the proportions of positive PGTsare significantly lower. This could probablybe explained by the relatively low sensitiv-ity of the 10 grani monofilament sensibi I itytest for mild sensihility loss of the footsole.More sensitive sensihility testing, with a 2grani monofilament, for example, should heperformed in these patients. Also, sensihil-ity was regarded as normal when a patientwas atile to indicate ali three regions ofpressure stirniiius with their eyes closed atleast one out of three times. This will noteliminate some errors due to guessing andthis could lead to an underestimation ofsensihility loss in the leprosy group.

The exclusion of patients with foot defor-mities gives an underestimation of the per-centage of leprosy patients with intrinsicmuscle weakness. it is likely that the major-ity of thern have paralysis of intrinsic footmuscles.

The influence of the use of different typesof paper slips and different types of under-ground is not investigated in our study.When the paper s l i p used is too th i n, thetearing point of the paper will become cri ti-cal to identifying the threshold for a nega-tive test: therefore, we recommend stan-dardization of the paper quality and papersize. We would advise the size and type ofpaper used for business cards (at least 100g/m 2), because this paper will not easi ly tearand is widely available. Also the directionand rate of force, the arei where the force isapplied to the paper and testing surfacecould probably influence the outcome of thePGT. Again, we recommend standardizationof these as a further objective of this study.

It would also he interesting to correlatethe PGT results with additional variables,such as presence of ulcer/scar at certainsites and site of anesthesia to increase thevalidity of the PGT.

SUMMA RYPlantar intrinsic foot muscles provide

structure to the foot during walking and thusrego late mechan ical foot sole stresses. Whenparalyzed, for instance in leprosy patients

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with neuropathy of the distai pari of the tibialverve, there is a high prevalence of plantar ul-ceration and deformities, especially whenmuscle weakness goes together with loss offoot sole sensibility. These patients should getimmediate cace involving education, specialfootwear and reconstructive surgery beforefurther foot impairment and deformity be-comes manifest. Thus far, in leprosy patientslittle attention is paid to screening of plantarintrinsic muscles activity. This can be donewith a new simple and non-invasive method,the Paper Grip Test (PGT). There are twovariants for detecting intrinsic muscle weak-ness of the foot, PGT 1 for the great toe andPGT2 for the combined lesser toes.

In Chis study, 517 leprosy patients and170 healthy volunteers were investigatedwith the PGT. Sensibility of the foot solewas tested by means of a 10 gram mono-filament. Specilicity to the PGT1 is foundto be about 95.3% which is consideredgood for physical diagnostic tests. PGT2 isless specific than PGT1. Individual musclepower and understanding of the patientseems to iniluence the outcome of the testto a certain extent. Sensitivity can only becalculated when the diagnosis is conlirmedby electromyography.

Especially patients with anesthetic feet,females, older patients and patients withPN-, BB- or LL-types of leprosy appearedto have a higher prevalence of intrinsic footmuscle weakness. All results were analyzedby means of the bivariate Pearson correla-tion-analysis and proved to be statisticallysignificam (p = <0.05). It is concluded thatthe PGT1, more than the PGT2, is a usefulscreening test on the function of plantar in-trinsic foot muscles in leprosy patients inhospitais and during fieldwork in develop-ing countries.

RESUMENLos músculos plantares intrínsecos dcl pie propor-

cionan la estructura requerida para caminar y regulanel esta-5s mecánico de la planta dei pie. Cuando se par-alizan, por ejemplo en los pacientes con neuropatia dela parte distai dei nervio tibial, ocurre una alta inciden-cia tanto de ulceras plantares como de deformidades,especialmente cuando la debilidad muscular está aso-ciada con la pérdida de sensibi1idad plantar. Los pa-cientes con debilidad de los músculos plantares in-trínsecos dcl pie deben recibir atención inmediata, in-cluyendo cducación, calzado especial y cirugíareconstructive, antes de que la disfunción y deformi-

dad se hagan aparentes. Hasta ahora se ha dado pocaatención al exames de la actividad de los músculos in-trínsecos plantares en los pacientes con lepra. Sin em-bargo, el examen puede hacerse con un método simpley no invasivo referido como la prueba de sujeción dclpapel o Papei Grip Test (PGT). De este método exis-tes dos variantes, la PGT1 para el dedo grande dei piey la PGT2 para el conjunto de los dedos pequenos.

En este estudio. se investigaron 517 pacientes conlepra y 170 voluntarios canos con la prueba PGT. Lasensibilidad de la planta dcl pie se probó usando unmonolilamento de 10 gramos. Se encontró que la es-peci licidad de la PGT1 fue del 95.3%, lo cual se consid-era bueno para pruebas de diagnóstico físico. La PGT2es menos específica que la prueha PGTI . La potencia delos músculos individuales y el trato a los pacientes,parecen influir, en cierto grado, en el resultado de laprueha. La sensihilidad sólo se puede calcular cuando eldiagnóstico se ha confirmado por electromiografía.

Los pacientes con pie anestésico, los pacientes fe-meninos, los pacientes viejos y los pacientes con lepraPN, BB o LL mostraron una alta Irecuencia de debilidadde los músculos intrínsecos dei pie. Todos los resultadosse analizaron usando el análisis de correlación bivariadode Pearson y fueron estadísticamente significativos (p<0.05). Se concluye que la PGT1, más que la PGT2, esuna prueba útil para la exploración de la función de losmúsculos intrínsecos deI pie en los pacientes con lepra yque es aplicahle tanto en los hospitales como en el tra-bajo de campo, en los países en desarrollo.

RÉSUMÉLes muscles plantaires intrinsèques garantissent le

maintien structurel du pied lors de la marche et régu-lent ainsi les stress mécaniques plantaires. Lors deparalysies, comme par exemple lorsqu'un lépreuxprésente une neuropathie de la partie distale du nerftibial, une forte prévalence d'ulcérations plantaires etde déformtaions est observée, en particulier lorsqu'unefaiblesse musculaire est accompagnée d'une perle desensibilité de la plante du pied. Ces patients doiventsans délais bénéficier de soins comprenant une infor-mation spécifique et des chaussures spécialisées, ainsiqu'une chirurgie réparatrice avant que le handicap et ladéformation du pied ne deviennent trop marqués.Jusqu'ìt présent, les patients hanséniens n'ont bénéficiéque de pcu d'intérêt pour un dépistage de 1'activité desmuscles plantaires intrinsèques. Cela peut maintenantêtre réalisé au moyen d'une méthode simple et non-invasive, le test de préhension du papier (PGT). II y adeux variantes de la méthode pour détecter les fai-blesses des muscles plantaires intrinsèques : PGTIpour le gros orteil et PGT2 pour les autres orteils.

Dans cette étudgi, 517 patients hanséniens et 170volontaires soins furent étudiés au moyen du test PGT.La sensibilité plantaire fut évaluée à 1'aide d'uninonoti1ament de 10 grammes. La spécificité du testPGT I est d'environ 95,5%, ce qui est considérécota me satisfaisant parmi les tests physiques de diag-nostic. PGT2 est moins spécifique que PGTI . La force

24^ International ,JOurn(!I of . Le/)/'osv^ 2002

nlusculail'e interindividuelle et la connpréhension dupatient senlhlent influencer dans une certaine mesurele résultat du test. La sensibilité de la techniyue ne peutêtre calculée chie lorsdue le diagnostic est contìrmé parélectromyographie.

Une prévalence plus élevée de faiblesse des mus-eles plantaires intrinsèdues était notée chez les patientsavec des l)ieds anesthésiés, les femmes, les patientsâgés et ceux souffrant de lèpre de type PN, BB et LL.Tous les résultats furent analysés à l'aide d'un test decorrélation à deux variables de Pearson et étaient sta-tistiyuement significatifs (p = <0,05). En conclusion,PGT 1, plus que PGT2, est un test de dépistage ut I Lpour le dépistage de l'altération fonctionnelle des mus-eles intrinsèyues du pied parmi les patients lépreuxhospitalisés ou bien dans les actions sur le terral') dansles pays en voie de développement.

Acknowledgement. The authors want to thank theLeprosy Mission International and Leprosy MissionPni u1ia. Especially Dr. Kiran Sarkar, reconstructivesurgeon, for supervision during the project and thephysiotechnicians of the Purlllia hospital staff for thcirhelp in sensihility testing and translation. We also wantto thank Prof. Dr. F.G.I. Jennekens for his valuable re-marks (111 the mannscript.

Funding for this project Ias been provided hyversiteitsfonds Limhurg/SWOL and the medicai fac-ulty of Maastricht University.

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