Background:Athleteshavebeenshowntoexhibitbetterbalancecomparedtonon-athletes(NON).However,fewstudieshaveinvestigatedhowthesurfaceonwhichathletestrainaffectsthestrategiesadoptedtomaintainbalance.Twodistinctathletegroupswhoexperiencedifferenttypesofsport-specificbalancetrainingarestablesurfaceathletes(SSA)suchasbasketballplayersandthosewhotrainonunstablesurfaces(USA)suchassurfers.ThepurposeofthisstudywastoinvestigatetheeffectsoftrainingsurfaceondynamicbalanceinathletescomparedtoNON.Methods:EightNON,eightSSA,andeightUSAperformedfive20-strialsineachoffiveexperimentalconditionsincludingastaticconditionandfourdynamicconditionsinwhichthesupportsurfacetranslatedintheanteroposterior(AP)ormediolateral(ML)planesusingpositiveornegativefeedbackparadigms.Approximateentropy(ApEn)androotmeansquaredistance(RMS)ofthecenterofpressure(CoP)werecalculatedfortheAPandMLdirections.Four3×5(group×condition)repeatedmeasuresANOVAswereusedtodeterminesignificanteffectsofgroupandconditiononvariablesofinterest.Results:USAexhibitedsmallerApEnvaluesthanSSAintheAPsignalswhilenosignificantdifferenceswereobservedintheMLCoPsignals.Generally,thenegativefeedbackconditionswereassociatedwithsignificantlygreaterRMSvaluesthanthepositivefeedbackconditions.Conclusion:USAexhibituniqueposturalstrategiescomparedtoSSA.Theseuniquestrategiesseeminglyexhibitadirection-specificattributeandmaybeassociatedwithpergentmotorcontrolstrategies.