简介:Gaitrecognitionisthekeyquestionoffunctionalelectricalstimulation(FES)systemcontrolforparaplegicwalking.Anewrisk-tendency-graph(RTG)methodwasproposedtorecognizethestabilityinformationinFES-assistedwalkinggait.Themaininstrumentwasaspecializedwalkerdynamometersystembasedonamulti-channelstrain-gaugebridgenetworkfixedonthewalkerframe.Duringwalkingprocess,thissystemcollectedthereactionforcesbetweenpatient'supperextremitiesandwalkerandconvertedthemintoRTGmorphologiccurvesofdynamicgaitstabilityintemporalandspatialdomains.TodemonstratethepotentialusefulnessofRTG,preliminaryclinicaltrialsweredonewithparaplegicpatients.Thegaitstabilitylevelsoftwowalkingcaseswith4-and12-weekFEStrainingfromonesubjectwerequantified(0.43and0.19)fromtheresultsoftemporalandspatialRTG.Relevantinstablephasesingaitcycleanddangerousinclinationsofpatient'sbodyduringwalkingprocesswerealsobroughtforward.Inconclusion,thenewRTGmethodispracticalfordistinguishingmoreusefulgaitstabilityinformationforFESsystemcontrol.
简介:Theeffectsofexerciseondecision-makingperformancehavebeenstudiedusingawidevarietyofcognitivetasksandexerciseinterventions.Althoughthecurrentliteraturesupportsabeneficialinfluenceofacuteexerciseoncognitiveperformance,themechanismsunderlyingthisphenomenonhavenotyetbeenelucidated.Wereviewstudiesthatusedsingle-pulsetranscranialmagneticstimulation(TMS)toprobetheexcitabilityofmotorstructuresduringwhole-bodyexerciseandpresentaframeworktoaccountforthefacilitatingeffectsofacuteexerciseonmotorprocesses.Recentresultssuggestthat,evenintheabsenceoffatigue,theincreaseincorticospinalexcitabilityclassicallyreportedduringsubmaximalandexhaustingexercisesmaybeaccompaniedbyareductioninintracorticalinhibition.Weproposethatreducedintracorticalinhibitionelicitsanadaptivecentralmechanismthatcounteractstheprogressivereductioninmuscleresponsivenesscausedbyperipheralfatigue.Suchareductionwouldrenderthemotorcortexmoresensitivetoupstreaminfluences,thuscausingincreasedcorticospinalexcitability.Furthermore,reductionofintracorticalinhibitionmayaccountforthemoreefficientdescendingdriveandfortheimprovementofreactiontimeperformanceduringexercise.Theadaptivemodulationinintracorticalinhibitioncouldbeimplementedthroughageneralincreaseinreticularactivationthatwouldfurtheraccountforenhancedsensorysensitivity.