Case study: Use of surface electromyography in masseter to investigate the muscular effort and movement features during the naturally chewing and swallowing

Chewing and swallowing patterns was large described as a risk factor for degenerative diseases diagnosis. In this paper, the electromyography technique was used to collect the electrical potential from masseter muscle. Aiming to extract the movement features and muscular effort during chewing activity of a solid aliment - gummy. Was used an accelerometer - detecting the hand movement - to facilitate the visual segmentation of each mastigation and swallow signal. The maximum voluntary contraction was obtained by the forced chew in an Parafilm positioned between the molar teeths. The signal characteristics was obtained through those data analysis methods: Root Mean Square (RMS), Teager–Kaiser energy operator (TKEO) and double threshold. The protocol proceed was made with one health subject, adult, male, instructed to naturally chew the aliment. The results shows significant differences on the RMS value (p <0.01) between the first chewing stages and the final one (25, 50 and 75%). In conclusion, as shown in results, the electromyography can be used to detect the chewing pattern and stages - initial (bite) and final (swallow).