Age and Sex-Related Differences in the Tongue Pressure Generated during Maximum Isometric and Swallowing Tasks by Healthy Chinese Adults

The aims of this prospective observational study were to investigate age, sex, and factors related to the tongue pressure generated. A correlational research design was used. A total of 150 Chinese people who had a normal swallowing condition were enrolled by convenience sampling. Pressure was measured for each participant during maximum isometric press tasks, as well as for saliva and water swallows (5 mL) at the anterior and posterior tongue. The results illustrated that age has an impact on anterior tongue pressure (r = −0.22), posterior tongue pressure (r = −0.26); however, it does not have an impact on the swallowing pressure (SP) of the tongue. Sex differences were noted; males demonstrated a greater strength of the anterior tongue. There was a significant correlation between BMI and the maximum isometric pressure of the anterior tongue (MIPant). The pressures between anterior and posterior tongue were not significantly different in the maximum isometric or swallowing tasks. There were significant differences among the maximum isometric pressure (MIP), saliva swallowing pressure, and water swallowing pressure. The MIP generated was greater than the pressure in the swallowing tasks for the younger groups of both sexes. The study supplement the exploration of age-and-sex related differences and the interaction of sex and age in tongue pressure.

A model for the relation between respiratory neural and mechanical outputs. I. Theory

A model for the conversion of respiratory neural output to mechanical output, and vice versa, is described. Neural output was expressed in terms of isometric pressure generated at passive functional residual capacity. The mechanical response time constant of respiratory muscle was assumed to be 0.06 s. The effect of volume and configuration on pressure output was modeled after the data of Grassino et al. (J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 44: 829–839, 1978). Equations were developed to examine the effect of different configurational pathways during inspiration. We utilized Hill's hyperbolic force-velocity relation to model the effect of flow on pressure output. The pressure asymptote of the hyperbola was considered to be similar to that in other skeletal muscles (0.25 isometric pressure). The flow asymptote was derived from data obtained during maximal voluntary inspiration. A major feature of the model is the dependence of volume, configuration, and flow-related pressure losses on level of inspiratory activity. The practical effect of potential errors and the overall accuracy of the model are presented in the two succeeding communications.