简介：Background:Childrenareaffectedbydisordersthathaveanimpactontherespiratorymuscles.Inspiratorymusclefunctioncanbeassessedbymeansofthenoninvasivetension–timeindexoftheinspiratorymuscles(TTImus).OurobjectivesweretoidentifythedeterminantsofTTImusinhealthychildrenandtoreportnormalvaluesofTTImusinthispopulation.Methods:Wemeasuredweight,height,upperarmmusclearea(UAMA),andTTImusin96childrenaged6–18years.Thelevelandfrequencyofaerobicactivitywasassessedbyquestionnaire.Results:TTImuswassignificantlylowerinmalesubjects(0.095±0.038,mean±SD)comparedwithfemalesubjects(0.126±0.056)(p=0.002).TTImuswassignificantlylowerinregularlyexercising(0.093±0.040)comparedwithnonexercisingsubjects(0.130±0.053)(p<0.001).TTImuswassignificantlynegativelyrelatedtoage(r=-0.239,p=0.019),weight(r=-0.214,p=0.037),height(r=-0.355,p<0.001),andUAMA(r=-0.222,p=0.030).MultivariatelogisticregressionanalysisrevealedthatheightandaerobicexerciseweresignificantlyrelatedtoTTImusindependentlyofage,weight,andUAMA.ThepredictiveregressionequationforTTImusinmalesubjectswasTTImus=0.228-0.001×height(cm),andinfemalesubjectsitwasTTImus=0.320-0.001×height(cm).Conclusion:Gender,age,anthropometry,skeletalmuscularity,andaerobicexercisearesignificantlyassociatedwithindicesofinspiratorymusclefunctioninchildren.NormalvaluesofTTImusinhealthychildrenarereported.