Use of electromagnetic midsagittal articulography in the study of swallowing.

The tongue functions as the primary articulator during the oropharyngeal stages of swallowing. However, detailed descriptions of the kinematics and spatiotemporal variability of tongue behaviors during swallowing are limited to a handful of analyses of data from the X-ray microbeam database. In this article, a new technique, electromagnetic midsagittal articulography (EMMA), is introduced for the high-resolution description of oral articulatory movements during swallowing. Data from 8 healthy, nondysphagic participants are used to illustrate the methods used for data collection and analysis. Movement data were collected for 3 fleshpoint positions on the tongue (blade, body, dorsum) during sequences of repeated discrete water swallows, and were characterized for variables of spatiotemporal variability and 4 discrete kinematic parameters (movement amplitude, peak velocity, duration, and kinematic stiffness). These data show that the movement trajectories measured using EMMA are consistent with descriptions from previous X-ray microbeam studies, indicating that EMMA is a feasible method for the detailed study of tongue movements during swallowing.