简介：

简介：Background:Infraredthermographicimaging(IRTG)isasafeandreliabletechnologyusedtomonitorskintemperature.ThemainaimofourstudywastoevaluatetherelationshipbetweenskintemperaturechangesandmusclefatigueinordertoanswerthemainresearchquestionifIRTGcanbeusedtomonitormusclefatigue.Methods:Thiswasacasestudyperformedona23-year-oldtrainedmiddledistancerunner.Afterwarm-upthesubjectwasexercisingonthedynamometerfor7.5minat120?/sperformingonlyconcentriccontractionsofquadriceps.AtthesametimeIRTGrecordingofboth(exercisingandnon-exercising)quadricepswasperformed.Results:Acorrelationalanalysisthatwasperformedinordertoquantifytherelationshipbetweenpowerandtemperaturechangeovertimehasshownthatthereisasignificantnegativecorrelationbetweenskintemperatureincreaseandpowerdecrease(r=-0.543,p=0.036)ofexercisingquadriceps.Inlinearregressionmodeltheexercisingquadricepspowercouldbepredictedfromskintemperature.Nosuchrelationshipswerenotedforthenon-exercisinglimbthatservedasacontrol.Conclusion:Webelievethatcorrelationbetweenskintemperaturechangeandmusclepoweroutputasdescribedinthiscasestudydeservesfurtheranalysisonthelargersampleincludingsubjectsofthedifferentages,healthstatus,andphysicalabilitiesinordertocreateanewtoolformonitoringthemusclefatigue.

简介：Background:Marginalchangesintheexecutionofcompetitivesportsmovementscanrepresentasignificantchangeforperformancesuccess.However,suchdifferencesmayemergeonlyatcertainexecutionintensitiesandarenoteasilydetectablethroughconventionalbiomechanicaltechniques.Thisstudyaimedtoinvestigateifandhowcompetitionstandardandprogressionspeedaffectracewalkingkinematicsfrombothaconventionalandacoordinationvariabilityperspective.Methods:Fifteenexperiencedathletesdividedintothreegroups(elite,international,andnational)werestudiedwhileracewalkingonatreadmillattwodifferentspeeds(12.0and15.5km/h).Basicgaitparameters,theangulardisplacementofthepelvisandlowerlimbs,andthevariabilityincontinuousrelativephasebetweensixdifferentjointcouplingswereanalyzed.Results:Mostofthespatio-temporal,kinematic,andcoordinationvariabilitymeasuresprovedsensitivetothechangeinspeed.Conversely,non-lineardynamicsmeasureshighlighteddifferencesbetweenathletesofdifferentcompetitionstandardwhenconventionalanalyticaltoolswerenotabletodiscriminatebetweendifferentskilllevels.Continuousrelativephasevariabilitywashigherfornationallevelathletesthaninternationalandeliteintwocouplings(pelvisobliquity—hipflex/extensionandpelvisrotation—ankledorsi/plantarflexion)andgaitphases(earlystanceforthefirstcoupling,propulsivephaseforthesecond)thataredeemedfundamentalforcorrecttechniqueandperformance.Conclusion:Measuresofcoordinationvariabilityshowedtobeamoresensitivetoolforthefinedetectionofskill-dependentfactorsincompetitiveracewalking,andshowedgoodpotentialforbeingintegratedintheassessmentandmonitoringofsportsmotorabilities.

简介：

简介：Background:Animpactofregularphysicalactivity(RPA)ontheabdominalmusclesmaybesignificantwhencomparingvarioussymptomaticgroups.However,thereislackcomprehensiveinformationinthisfield.Theobjectiveofthisstudywastoassessthelateralabdominalwallatrestandduringabdominaldrawing-inmanoeuvreinadolescentphysicallyactivegirlsindifferentbodypositions.Methods:Onehundredandforty-fourfemalestudents,13–17yearsofage,participatedinthestudy.Participantsweredividedinto2groupsbasedonaphysicalactivity(PA)statement.Measurementsofthethicknessoftheabdominalmusclesatrestandduringabdominaldrawing-inmanoeuvreweremadeinthesupineandstandingpositionsbyultrasoundimaging.Results:Comparedtothecontrolgroup,activitiesoftheobliquusinternusandtransversusabdominismuscleswerehigherintheregularPAgroupby8.9%(95%CI:3.1–14.7)and36%(95%CI:19.1–47.5),respectively.IntheRPAgroup,thetransversusabdominispreferentialactivationratiowasgreaterby0.03(95%CI:0.01–0.04),andthecontractionratiowasgreaterbyameanvalueof0.35(95%CI:0.18–0.46).Conclusion:RPAdoesnothaveanyeffectontherestingthicknessoftheabdominalmusclesinthesupineandstandingpositions.GirlsperformingRPAhaveagreaterabilitytoperformanindependentactivationandgreatercontractionsofthetransversusabdominis.