Effects Of Swallowing Different Viscosities And Volumes Of Liquid On The Activation Characteristics Of The Hyoid Muscles In Healthy Adults

Purpose:This work aims to study the effect of swallowing different viscosities and volumes of fluids on the activation characteristics of hyoid muscles in healthy adults based on five viscosity grades defined in the latest International Dysphagia Diet Standardisation Initiative(IDDSI)framework.This work aims to gain a deeper understanding of the effects of viscosity and volume on the hyoid muscles when participating in swallowing activities,and to provide a reference for clinical treatment and evaluation.Method:Altogether 44 healthy adults(19 males,25 females)randomly swallowed 15 types of bolus while being measured with surface electromyography.These boluses include 5 viscosities(grades 0,1,2,3 and 4)and 3 volumes(5ml,10 ml and 20ml).After analysis and processing of the raw sEMG signals,a three-way repeated-measures analysis of variance,which included viscosity and volume as within-subjects factors and muscle as the between-subjects factor,was conducted on sEMG amplitude value of muscle activity.Tests of simple effects were performed to explore interactions.Result:1.In the same volume,the activation level of the suprahyoid muscles was hardly affected by the viscosity of the liquid,except that the activation level of the suprahyoid muscles was significantly higher than that of 5ml level 0 when swallowing 5ml of level 4 fluid.2.In the same volume,the activation level of the infrahyoid muscles is hardly affected by the viscosity of liquid.3.In the same volume,the comparison of activation levels between the suprahyoid muscles and the infrahyoid muscles when swallowing liquids of different viscosities shows that,except that no significant difference was found when swallowing 10 ml of level 0 liquid,the activation level of the suprahyoid muscles obtained when swallowing a volume of 5 or 10 ml of different viscosity was significantly higher than that of the infrahyoid muscles.When the volume was increased to 20 ml,no significant difference was found between the activation levels of the superior and inferior hyoid muscles when swallowing fluids of different viscosities.4.In the same viscosity,when swallowing different volumes of liquid,the activation level of the suprahyoid muscles obtained by swallowing 20 ml liquid of 0,1,2 or 4 level is significantly higher than 5ml.The level of activation of the suprahyoid muscles obtained by swallowing 20 ml liquid of level 1 or 4 was significantly higher than that of 10 ml.No significant differences were found in the rest.5.In the same viscosity,when level 0 or 1 fluid is swallowed,as the volume increases,the activation level of the infrahyoid muscles increases in turn.When swallowing level 2,3,or 4 fluids,as the volume increased,the activation level of the infrahyoid muscles also increased significantly,with the exception of no significant differences found between 5ml and 10 ml.6.In the same viscosity,the comparison of activation levels between the suprahyoid muscles and infrahyoid muscles when swallowing liquids of different volumes shows that for level 0 fluids,the activation level of the suprahyoid muscles was significantly higher than that of the infrahyoid muscles when only 5 ml was swallowed.For level 1,2,3,or 4 fluids,the activation level of the suprahyoid muscles was significantly higher than that of the infrahyoid muscles when swallowed 5 ml or 10 ml,and no significant difference was found in the rest.Conclusion:1.When healthy adults swallow the same amount of liquid food,the activation level of the superior and inferior hyoid muscles is hardly affected by the viscosity levels of the IDDSI framework.2.When healthy adults swallow liquid food of the same viscosity,the activation level of the superior and inferior hyoid muscles increases with the increase of the mouthful,and compared with suprahyoid muscle group,the activation level of infrahyoid muscle group is more affected by volume.3.When healthy adults swallow liquid food,with the increase of volume,the activation level of infrahyoid muscle group is closer to that of suprahyoid muscle group,and the difference between them is smaller and smaller.