Do ankle braces provide similar effects on ankle biomechanical variables in subjects with and without chronic ankle instability during landing?

<正>Purpose:Thepurposeofthisstudywastoexamineeffectsofasportversionofasemi-rigidanklebrace(ElementTM)andasoftanklebrace（ASO）onanklebiomechanicsandgroundreactionforces（GRFs）duringadroplandingactivityinsubjectswithchronicankleinstability(CADcomparedtohealthysubjectswithnohistoryofCAI.Methods:Tenhealthysubjectsand10subjectswhohadmultipleanklesprainsparticipatedinthestudyasthecontrolandunstablesubjects,respectively.TheCAIsubjectswereage,bodymassindexandgendermatchedwiththecontrolsubjects.Thearchindexandanklefunctionsofthesubjectsweremeasuredinasubjectscreeningsession.Duringthebiomechanicaltestsession,participantsperformedfivetrialsofdroplandingfrom0.6m,wearingnobrace（NB）.Element?braceandASObrace.Simultaneousrecordingofthree-dimensionalkinematic（240Hz）andGRF（1200Hz）datawereperformed.Results:TheCAIsubjectshadloweranklefunctionalsurveyscores.ThearchindexanddeformityresultsshowedgreaterarchdeformityofElementTMagainstastaticloadthaninNBandASOduetogreaterinitialarchpositionheldbythebrace.CAIparticipantshadgreatereversionvelocitythanhealthycontrols.TheASObracereducedthefirstpeakverticalGRFwhereasElementTMincreased2ndpeakverticalGRF.ElementTMbracereducedeversionrangeofmotion（ROM）andpeakeversionvelocitycomparedtoNBandASO.Inaddition,ElementTMreduceddorsiflexionROMandincreasedpeakplantarflexionmomentcomparedtoNBandASO.Conclusion:Resultsofstaticarchmeasurementsanddynamicanklemotionsuggestthattherestrictionsofferedbybothbracesareinpartduetomoredorsiflexedanklepositionsatcontact,andhigherinitialarchpositionandstifferankleforElementTM.