简介：<正>Purpose:Thepurposeofthisstudywastoinvestigatelowerextremityneuromuscularactivitypatternsduringgaittransitionswithcontinuouslychanginglocomotionspeeds.Methods:Muscularactivitiesrelatedtogaittransitions(walktorunandruntowalk)inducedbychangingtreadmillspeedwerecomparedtomuscularactivitiesduringwalkandrunatconstantspeeds.Alltransitionandconstantspeedconditionswereconductedinsimilarspeedrange.Surfaceelectromyographicactivitiesofgluteusmaximus(GM),rectusfemoris(RF),vastuslateralis(VL),bicepsfemorislonghead(BFL),tibialisanterior(TA),gastrocnemius(GA),andsoleus(SL)werecollectedandanalyzed.Theinfluencesofspeedandmodeoflocomotionwereanalyzed.Results:Wehaveobservedtransitionspecificnonlinearmuscularbehaviorinthisstudy.Forexample,peakmagnitudesofGM,RF,GA,andSLincreasedwithspeedquadraticallyaslocomotionapproachedwalktoruntransitionwithinthelastfivesteps.ActivitydurationofGAdecreasedinaquadraticfashionwithspeedasapproachedruntowalktransitionwithinthelastfivesteps.Thesenonlinearreactionstospeedchangewereonlyobservedintransitionrelatedconditionsbutnotintheconstantspeedconditions.Conclusion:Theseresultsindicatedthat,inpreparationfortransition,neuromuscularmodificationsoccurstepsbeforegaittransitionduetochangingspeed.Gaittransitionisnotaspontaneouseventinresponsetoanytypeoftriggers.