SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA
w w w . r b o . o r g . b r
Original
Article
Oscillation
of
plantar
pressure
center
in
athletes
and
non-athletes
with
and
without
ankle
sprains
夽
André
Kenzo
Saito
a,
Martina
Navarro
b,∗,
Marcelo
Faria
Silva
c,
Eduardo
Kenzo
Arie
d,
Maria
Stella
Peccin
eaUniversidadeFederaldeSãoPaulo,Santos,SP,Brazil
bUniversidadeFederaldeSãoPaulo,DepartamentodeOftalmologia,SãoPaulo,SP,Brazil
cUniversidadeFederaldeCiênciasdaSaúdedePortoAlegre,PortoAlegre,RS,Brazil
dIrmandadedaSantaCasadaMisericórdiadeSantos,Servic¸odeOrtopedia,Santos,SP,Brazil
eUniversidadeFederaldeSãoPaulo,DepartamentodeCiênciasdoMovimentoHumano,SãoPaulo,SP,Brazil
a
r
t
i
c
l
e
i
n
f
o
Articlehistory: Received15June2015 Accepted5October2015 Availableonline6June2016
Keywords: Ankleinjuries Foot
Pressure Posturalbalance
a
b
s
t
r
a
c
t
Objective:Toassesswhetherthereisanydifferenceintheoscillationoftheplantar pres-surecenterinsingle-legstancebetweenathletesandnon-athleteswithandwithoutankle sprains.
Methods:54volunteersperformedfourstaticassessmentsandonedynamicassessment whilestandingononefootonabaropodometer,barefoot,for10sineachtest.The vari-ablesofarea(cm2),distance(cm),anteroposterioroscillation(cm),mediolateraloscillation
(cm)andmeanvelocity(cm/s)wereanalyzed.Theitems“other symptoms”and“sports andrecreation”ofthesubjectiveFootandAnkleOutcomeScore(FAOS)questionnairewere applied.Forthestatisticalanalysis,repeated-measurementANOVA(ANOVA-MR), multivari-ateANOVA(MANOVA),Tukey’sposthoctestandpartialetasquaredwereused.
Results:ANOVA-MR revealeddifferences regardingdistance, withmajoreffectsforeyes (p<0.001),knees(p<0.001),group(p<0.05) andtheinteractionbetweeneyesandknees (p<0.05);andregardingmeanvelocitywithmajoreffectsforeyes(p<0.001),knees(p<0.001) (p<0.05),group(p<0.05)andtheinteractionbetweeneyesandknees(p<0.05).MANOVA revealedmaingroupeffectsfordistance(p<0.05),anteroposterioroscillation(p<0.05)and meanvelocity(p<0.05).IntheFAOSquestionnaire,therewerenodifferences:“other symp-toms”,p>0.05;and“sportandrecreation”,p>0.05.
Conclusion: Athletespresenthighermeanvelocityofoscillationofplantarpressurecenter andgenerallydonothavedifferencesinoscillationamplitudeinthesagittalandcoronal planes,incomparisonwithnon-athletes.
©2016SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).
夽
StudyconductedatSantosArenaandUniversidadeFederaldeSãoPaulo(Unifesp),LaboratóriodeExercíciosTerapêuticos,Santos,SP, Brazil.
∗ Correspondingauthor.
E-mail:navarro.mna@gmail.com(M.Navarro). http://dx.doi.org/10.1016/j.rboe.2016.05.003
Oscilac¸ão
do
centro
de
pressão
plantar
de
atletas
e
não
atletas
com
e
sem
entorse
de
tornozelo
Palavras-chave:
Traumatismosdotornozelo Pé
Pressão
Equilíbriopostural
r
e
s
u
m
o
Objetivo: Avaliarsehádiferenc¸aquantoàoscilac¸ãodocentrodepressãoplantaremapoio unipodalentreatletasenãoatletascomesementorsedetornozelo.
Método: Fizeramquatroavaliac¸õesestáticaseumadinâmicaemapoiounipodaldescalc¸o sobreobaropodômetro54 voluntarios,comdurac¸ão de10 segundoscadateste.Foram analisadasasvariáveisárea(cm2),distância(cm),oscilac¸ãoanteroposterior(cm),oscilac¸ão
mediolateral(cm)evelocidademédia(cm/s).Foramaplicadosositens“Outrossintomas”e “Esporteerecreac¸ão”doquestionáriosubjetivoFootandAnkleOutcomeScore(FAOS).Para aanáliseestatísticaforamusadasaANOVAdemédiasrepetidas(ANOVA-MR),aANOVA multivariada(MANOVA),oposthocdeTukeyeopartialetasquare.
Resultados: AANOVA-MRreveloudiferenc¸asparadistância,comefeitosprincipaispara olhos(p<0,001),joelho(p<0,001),grupo(p<0,05)einterac¸ãoolhosejoelho(p<0,05)epara avelocidademédiacomefeitosprincipaisparaolhos(p<0,001),joelho(p<0,001),grupo (p<0,05)einterac¸ãoolhosejoelho(p<0,05).AMANOVArevelouefeitosprincipaisdegrupo paradistância(p<0,05),oscilac¸ãoanteroposterior(p<0,05)evelocidademédia(p<0,05).No questionárioFAOSnãohouvediferenc¸as(“Outrossintomas”[p>0,05],“Esporteeeecreac¸ão” [p>0,05]).
Conclusão: Atletasapresentammaiorvelocidademédiadeoscilac¸ãodocentrodepressão plantarenãoapresentam,demodogeral,diferenc¸asquantoàamplitudedeoscilac¸ãonos planossagitalecoronalquandocomparadoscomnãoatletas.
©2016SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Este ´eumartigoOpenAccesssobumalicenc¸aCCBY-NC-ND(http:// creativecommons.org/licenses/by-nc-nd/4.0/).
Introduction
Injuriesduetoanklesprainsmaycauseneuromuscularand mechanical damageto the joint,predispose torecurrence, andcompromiseposturalcontrolandperformanceofmotor activities.1–6Consideringtheeffectsoftheinjuryonpostural
control,individualswithchronicinstabilitypresentmoretime for stabilization when compared with individuals without injury, despitenotpresentingdifferences regarding oscilla-tionsinthesagittalandcoronalplanes.Thislastfactpossibly occursbecauseindividualswithinstabilitydevelop compen-satorystrategiestokeeptheplantarcenterofpressure(PCP) withinthelimitsofstability.7
Court-basedsports require the implementation of com-plexmotortasks.Inordertoperformthenecessarysporting movement,adequate posturecontroland stabilityare very important.Athletesareoftennotattentivetothesupporting surface; thus,sprains are frequent insports, especiallyon courts,8–11whichcancompromisestabilityandpostural
con-trol.Whencomparedwithnon-athletes,athleteshavelower variabilityofthecenterofpressure,i.e.,greaterstability dur-ingunipedalstance,suggestinggreaterneuromotordemand duetothesport.Anotherfactisthatathletesalsohavehigher meancenterofpressurevelocity,explainedbytheprincipleof stochasticresonance(SR),whichmaybebetterdevelopedin athletes.12
In the muscle tissue, SR is the ability ofsensory noise topotentiatesubthresholdsensoriomotorsignalsinagiven stimulatedregionandallowforanincreasedthreshold,which in turn leads to its detection and consequent response to
afferentactivity,inthiscasethecontraction.13,14Apparently,
highlytrainedathleteswhodependontheirstabilityto exe-cuteagoodmotoractionhavelearnedhowtomakeuseofthis featureand,therefore,facilitateaquickcontraction.However, todatetherearenostudiesthatinvestigatedwhatoccursin trainedathleteswithahistoryofsprains.
Inshort,despitetherateofhighankleinjurypersprain insportsandtheimportanceofposturalcontrol,nostudies comparingposturalcontrolamongathletesandnon-athletes withandwithoutsprainwereretrieved.Therefore,thisstudy aimedtoassesswhetherthereisdifferenceintheoscillation ofthePCPinunipedalstanceamongathletesandnon-athletes withandwithoutanklesprain.AccordingtotheSRprinciple, theauthorshypothesizedthatathletesingeneralhavehigher averagevelocityandloweramplitudeofoscillationofthePCP thannon-athletes.
Material
and
methods
Participants
tocompleteatleastoneofthetests,aswellasthosewhohad otherinjuriesinlowerlimbsandtrunk,neurologicalinjuries, andacutesprainsthathinderedevaluations.
ThestudywasapprovedbytheEthicsCommitteeofthe FederalUniversityofSãoPaulo.Allvolunteerssignedafree andinformedconsentform.Datacollectionwasconductedin thelaboratory.
Studydesign
Thevolunteers were subjected tostatic assessments(four tests)anddynamic(one).Alltestsweredoneintheunipedal stanceontheMatScanSystembaropodometer,version6.60 (TeckscanInc.,Boston,MA,UnitedStates)withthefollowing dimensions:620mm×645mm,scanningspeedof100Hz,and 8-bitpressuredigitalresolutionfortheanalysisofthelower limb(LL)withworseseveritysprainforvolunteerswho suf-feredsprains;forvolunteerswithoutsprain,theLLwasdrawn regardlessofdominance.Thesystemwascalibratedforthe weightofparticipantandaccordingtothemanufacturer’s pro-tocol.
The duration of each test was 10s,6 with a 20-s
inter-valbetweenthem.Theanglesweremeasuredbyauniversal goniometer. Volunteers performed three attemptsfor each test; only the data from the first complete attempt were considered.Theorderoftestswas randomizedbydrawing envelopesthatcontainedoneofthefiveteststobedone.
Static evaluation. In the four static tests, the participant wasrequiredtoremainbarefoot,intheunipedalstance,on abaropodometer.Thedifferencesbetweentests comprised whethertheeyeswereopenorclosed,andwhethertheLLwas stretchedorflexed.Thus,thefollowingtestswereperformed: Test1,hipandkneeextensionandopeneyes(OE);Test2,hip andknee extensionand closedeyes(CE);Test3,hipat30◦
andkneeat45◦ offlexionandOE;andTest4,hipat30◦and
kneeat45◦offlexionandCE.Datacollectioninstatictesting
wasinitiatedattheevaluator’scommandandautomatically completedattheendof10s.
Dynamicevaluation.Thevolunteer,barefoot,wasrequired toperform acountermovement verticaljump and landon thebaropodometer.Inthiscase,theequipmentautomatically startedcollectingdataonlyatlandingandfinishedafter10s. Thefollowingvariableswereanalyzed:area(cm2),defined asthe mean contact area (pressure points); distance(cm), definedasthe distancebetweenthepeak plantarpressure points;anteroposterioroscillation(APO;cm),definedasthe meanoscillationamplitudeinthesagittalplane;mediolateral oscillation(cm),definedasthemeanoscillationamplitudein thecoronalplane;andmeanvelocity(MV;cm/s),calculated bydividingthedistancebytestduration.Datawerecollected withtheSAMsoftware,usingthebaropodometerextension program.
Priortothebaropodometertest,theitems“Other symp-toms”’ and “Sport and recreation” from the subjective Foot and Ankle Outcome Score (FAOS) questionnaire were applied. In this questionnaire, higher scores mean subjec-tively better functional conditions. Although this factor is consideredtobeimportantbysomeauthors,15hindfoot
align-ment(varus/valgus)was notmeasured inthisstudy.There is still insufficient evidence as to the best measurement
methodologytobeappliedinclinicalpractice;sincethisstudy did not aim to compare the different methodologies, the authorschosenotmeasurethisvariable.
Statisticalanalysis
Thevariables area,distance,APO, andmediolateral oscilla-tion wereanalyzed,and theMVwascalculated bydividing the distance by the test time. The variables of the static testsunderwent 2(knee: flexedorextended)×2(eye:open orclosed)×4(group:athletesornon-athleteswithand with-outsprain)analysisandananalysisofvarianceforrepeated measures (ANOVA-RM).For the jumpand the items ofthe FAOSquestionnaire,multivariateANOVA(MANOVA)wasused amonggroups.PosthoccomparisonswithTukey’scorrection andpartialetasquare(2P)wereusedasmeasuresoftheeffect size.
Forallstatisticalanalyses,thesignificancelevelwassetat 5%andSPSS(version21)wasused.
Results
Ten subjects were excluded (Fig. 1); therefore, the study included54assessments:14femaleathletes(11sprains),14 maleathletes(sevensprains),11femalenon-athletes(seven sprains),and15malenon-athletes(ninesprains).
ANOVA-RMrevealeddifferencesonlyforthevariable dis-tance, withmajor effectsforeyes,F(1,53)=151.61,p<0.001,
2P=0.75; knee, F(1,53)=40.4, p<0.001, 2P=0.45; group, F(1,53)=15.59, p<0.05, 2P=0.24; and knee–eye interaction, F(1,53)=7.69,p<0.05,2P=0.13.FortheMVvariable,themain effectswereobservedforeyes,F(1,53)=151.58,p<0.001,2P= 0.75;knee,F(1,53)=40.4,p<0.001,2P=0.45;group,F(1,53)=5.2, p<0.05, 2P=0.24; and knee-eye interaction, F(1,53)=7.72, p<0.05,2P=0.13.Posthocanalysesforbothvariablesshowed differencesbetweenathleteswithoutsprainandbothgroups ofnon-athletes,withhighervaluesfortheformer.MANOVA dynamic test indicated important group effects for the variables distance, F(1,53)=14.84, p<0.05, 2P=0.23; APO, F(1,53)=9.47,p<0.05,2P=0.16;andMV,F(1,53)=9.95,p<0.05,
2P=0.23. Post hoc analyses for MVand distance indicated differences between athletes without sprainand the other groups;inturn,fortheAPOvariable,differenceswereobserved onlybetweenbothgroupsofathletes(Tables1–3).
Individuals without sprain had higher score on the FAOS questionnaireitemswhencomparedwiththosewith sprains. However, MANOVA revealed no statistically signif-icant differences (“Othersymptoms”: F(1,53)=2.74, p>0.05,
2P=0.141;“Sportandrecreation”:F(1,53)=1.48,p>0.05,2P= 0.082;Table4).
Discussion
Initial sample 64
Excluded 10
Age <18 years 5
1 Fifth metatarsal fracture 1 Ankle fracture
Included 54
ACL reconstruction 1
Unable to finish the tests
2
Athletes without sprain
10
Non-athletes with sprain
16
Non-athletes without sprain
10 Athletes with sprain
18
Fig.1–Flowchartshowingtheinitialandfinalstudysample.gr1.
Table1–Variablesfromthestatictest.
Area(cm2)
Athleteswithsprain Athleteswithoutsprain Non-athleteswithsprain Non-athleteswithoutsprain
EOEK 7.72(±4.9) 9.91(±7.14) 5.3(±4.05) 4.2(±2.27)
EOFK 7.52(±6.12) 10(±5.36) 7.44(±3.2) 5.57(±3.3)
ECEK 18.52(±12.62) 27.46(±15.95) 15.99(±5.73) 13.11(±3.79)
ECFK 29.21(±31.96) 33.78(±24.08) 21.35(±11.94) 31.34(±25.74)
Distance(cm)
EOEK 58.45(±27.31) 89.44(±54.05)a,b 48.16(±16.39)a 40.17(±11.85)b
EOFK 65.04(±27.95) 103.29(±55.01) 59.18(±11.43) 51.11(±14.53)
ECEK 104.25(±49.87) 155.48(±78.83) 94.58(±24.94) 74.56(±15.58)
ECFK 138.05(±70.22) 170.68(±90.74) 114.71(±30.51) 130.74(±62.72)
Anteroposterioroscillation(cm)
EOEK 4.19(±1.67) 5.1(±2.42) 3.29(±1.41) 2.91(±0.82)
EOFK 3.84(±1.9) 4.91(±1.8) 4.24(±1.34) 3.59(±0.99)
ECEK 7.04(±3.59) 9.83(±5.12) 7.45(±3.62) 5.51(±1.13)
ECFK 8.18(±4.39) 10.25(±5.32) 7.84(±3.02) 8.73(±4.11)
Mediolateraloscillation(cm)
EOEK 3.2(±0.78) 3.31(±1) 2.6(±0.84) 2.58(±0.81)
EOFK 3.36(±1.22) 3.81(±0.96) 3.07(±0.77) 2.89(±0.96)
ECEK 4.72(±1.05) 5.04(±1.29) 4.34(±1.55) 4.22(±0.71)
ECFK 5.9(±2.8) 5.71(±2.12) 4.84(±1.06) 6.25(±3.61)
Mean(standarddeviation)ofthedistancevariable.
EOEK,eyesopen,extendedknee;EOFK,eyesopen,flexedknee;ECEK,eyesclosed,extendedknee;ECFK,eyesclosed,flexedknee. a Statisticallysignificant(p<0.05).
Table2–Variablesfromthedynamictest.
Athleteswithsprain Athleteswithoutsprain Non-athleteswithsprain Non-athleteswithoutsprain
Area(cm2) 23.02(±10.54) 30.9(±24.37) 24.07(±22.02) 17.41(±7.1)
Distance(cm) 90.61(±27.37)a 122.78(±52.1)a,b,c 88.85(±18.79)b 72.93(±15.76)c
APoscillation(cm) 13.24(±3.8) 14.36(±3.64)b 13.71(±3.24) 10.11(±2.66)b
MLoscillation(cm) 4.5(±0.68) 5.36(±1.69) 4.95(±2.28) 4.31(±0.99)
Mean(standarddeviation)ofthejumpvariable. a Statisticallysignificant(p<0.05).
b Statisticallysignificant(p<0.05).
c Statisticallysignificant(p<0.05).
Table3–Meanvelocity(cm/s).
Athleteswithsprain Athleteswithoutsprain Non-athleteswithsprain Non-athleteswithoutsprain
EOEK 5.85(±2.73) 8.95(±5.4)b,c 4.82(±1.64)b 4.02(±1.19)c
EOFK 6.5(±2.8) 10.33(±5.5)b,c 5.92(±1.14)b 5.11(±1.45)c
ECEK 10.43(±4.99) 15.55(±7.88)b,c 9.46(±2.5)b 7.45(±1.55)c
ECFK 13.81(±7.02) 17.07(±9.07)b,c 11.47(±3.05)b 10.33(±2.99)c
Jump 90.61(±27.37)a 122.78(±52.1)a,b,c 88.85(±18.79)b 72.93(±15.76)c
Mean(standarddeviation)ofthemeanvelocityvariable.
EOEK,eyesopen,extendedknee;EOFK,eyesopen,flexedknee;ECEK,eyesclosed,extendedknee;ECFK,eyesclosed,flexedknee. a Statisticallysignificant(p<0.05).
b Statisticallysignificant(p<0.05).
c Statisticallysignificant(p<0.05).
mainhypothesisofthepresentstudywasthatathletes, espe-ciallythosewithoutsprain,wouldpresenthigherMVandless PCPoscillationwhencomparedwithnon-athletes.
Thishypothesis was partially confirmed. Theresults of static and dynamictests demonstrated greater MV forthe groupofathleteswithoutsprainwhencomparedwithathletes withsprainsandbothgroupsofnon-athletes.Thisincrease canbeexplainedbySRprinciple.Aspreviouslymentioned,SR canbeunderstoodastheabilityofsensorynoiseto potenti-atesubthresholdsensoriomotorsignalsinagivenstimulated regionandallowforanincreasedthreshold,whichinturn leadsto their detectionand consequent responseto affer-entactivity,inthiscase,contraction.13Kuczy ˜nskietal.12also
observedhigherPCPMVinsecond-divisionvolleyballplayers whencomparedwithnon-athletes.Theseauthorssuggested that higher MV in athletes corresponds to better postural control,possiblyasaresultofthetrainingroutine,6,9which
requires a constantly high level of neuromuscular control (highfrequencyofneuralfirings)duetotheexposureto dan-ger.Inthepresentstudy,theMVincreaseinathleteswithout sprain can beexplained bytheir increased neuromuscular controllevelfromtraining,which,inlinewiththeSRprinciple, mayindicatethathighlytrainableathletesapparently have theabilitytopotentiatesubthresholdsensoriomotorsignals,
andthereforeincreasetheactivationthresholdandthe con-tractionresponse.Thegroupofathleteswithsprainsdidnot presentahigherMVthanthegroupofnon-athletes.This indi-cates thattheinjurymay causeapossibledecrease inthis capacityduetothepossibleneuraldeficitsthatananklesprain cancause.
Contrarytoourexpectations,thegroupofathletes with-out sprainalsoshowed greater PCPoscillation,considering thedistancevariablefromthegroupsofnon-athletesinthe staticandjumptestsandhigherAPOwhencomparedwith thejumptestofnon-athleteswithoutsprain.Again,thestudy byKuczy ˜nskietal.12corroboratesthepresentresults,asthey
observeda greateroscillatory amplitude,specifically inthe sagittal plane, in volleyball players. These authors explain theirresultsfromtheskillleveloftheathletesstudied.The volunteers inthe study byKuczy ˜nskiet al.12 were
second-divisionathletes.Thisindicatesthat,althoughtheseathletes alreadypresentedSRmusclecapacity,theywerepossiblystill developing this ability and therefore did not yet have full control. Consequently, the lack of control reflects a larger oscillation amplitude,especiallyinrelationto thedistance variable, whichis moresensitive asit is calculatedby the distance betweenthe peak plantarpressure points. In the presentstudy,theathletespresentedaskilllevelsimilarto
Table4–Items“Othersymptoms”and“Sportandrecreation”oftheFAOSquestionnaire.
Athleteswithsprain Athleteswithoutsprain Non-athleteswithsprain Non-athleteswithoutsprain
Othersymptoms 81.35(±3.19) 90.36(±4.28) 86.6(±3.39) 96.07(±4.28)
Sportandrecreation 85.83(±3.78) 84.5(±5.08) 91.87(±4.01) 97(±5.08)
second-divisionvolleyballplayers;therefore,itcanbeargued thattheseathleteshavetheSRability,butarestilldeveloping itscontrol.
ThestudybyRossandGuskiewicz7foundnodifferencesin
therangeofAPOandmediolateraloscillationamong individ-ualswithstableandunstableankle.Nonetheless,individuals withinstabilitytooklongertobecomestable.Thisstudy cor-roborates the amplitudes of oscillations, but the time for stabilizationwasnotmeasuredduetoequipmentlimitations. Despitethe higherMVand distanceinathleteswithout sprain,theothervariablesshowednodifferencesamongthe groups.ThesefindingscorroboratethosebyKuczy ˜nskietal.,12
suggestingthattheoscillatoryamplitudeisnotdeterminant forMVincrease,whilethedistanceappearstobeimportant, especiallyindynamicsituations.
Additionally, the resultsshowed that vision and propri-oceptionare importantinmaintainingtheposture.16,17 The
integrationofafferent/efferentinformationtomaintain pos-tureandbalanceresultsinintermittentmusclesynergism,18
causingafluctuatingPCPpattern.19,20 Thedeficiencyofone
orbothmaycompromiseitsmaintenance.16,17Inthisstudy,
theclosedeyesandlandingtestsaimedtosimulatevolleyball situationsinwhichthevisualfocusisnotonthelandingsite. Undertheseconditions,floatingstandardswereobservedin allvolunteers,corroboratingtheresultsofotherstudies.19,20
Interestingly,thesepatternswerenotassociatedwithbeing anathleteornot.
Individuals without sprain scored higher on the items “Othersymptoms” and “Sportand recreation” ofthe FAOS questionnairewhencomparedwiththosewithsprains. How-ever,therewasnostatisticallysignificantdifference,which pointedonlytoatrend.Asthisisasubjectivequestionnaire, theresultscanbejustifiedbythefactthatallvolunteers con-tinuedtoperformtheiractivitiesasusual,regardlessofinjury history.
Theresults ofthis study indicate that athletes without sprainhavehigherMVofPCPoscillation,probablyinfluenced bytheSRprinciple,whileathleteswithsprain,despite hav-ingthesametrainingroutine,appeartohavelessinfluence duetotheinjuryhistoryandpossibleneuraldeficits result-ingfromsprains.Inaddition,second-divisionathleteshave greateroscillation,specificallyinthevariableofdistance.This potentiallyindicatesthattheyarestilldevelopingthisability. Thehigh variabilityofthedatacollectedmay bedueto differencesinequipmentandthesmallsamplesized.These canbeseenaslimitationsofthepresentstudy.Inthisstudy,a resistivebaropodometerwasused,whileotherstudies canon-icallyusedforceplatforms.Despitethehighreliabilityofforce platforms,highcostpreventstheirpopularizationinclinical practice.Nonetheless,theresistivebaropodometerappearsto beusefulinclinicalpractice,asitprovidesrelevantandrobust data,anditisaninexpensiveoptiontotheforceplatform.
Conclusion
Athleteshavehighermeanvelocityofplantarcenterof pres-sureoscillationanddonothave,ingeneral,differencesinthe oscillationamplitudeinthesagittalandcoronalplaneswhen comparedwithnon-athletes.
Conflicts
of
interest
Theauthorsdeclarenoconflictsofinterest.
Acknowledgements
To the Fundac¸ão Pró-Esporte de Santos (Fupes) and the Associac¸ãoNacionaldeEsportes(ANE)fortheircollaboration inthisstudy.
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