Contributions of Individual Muscles to the Submental Surface Electromyogram During Swallowing

Abstract

Submental surface electromyographic recordings are commonly used in the investigation of swallowing disorders. The measured electromyography is thought to reflect the actions of floor-of-mouth muscles. Although this is a reasonable assumption, to date there have been no investigations to delineate which muscles contribute to this surface recording. The primary goal of this experiment was to determine which muscles contribute most to the submental surface. Electromyography was recorded simultaneously from the submental surface as well as from five individual muscles: mylohyoid, anterior belly of the digastric, geniohyoid, genioglossus and platysma. Three analysis methods were performed to estimate individual muscle contributions: correlation, numeric, and analytic. For the numeric and analytic analyses, a linear model was defined and used to represent the relationship between the surface and intramuscular recordings. Muscles that received a high correlation, numeric and/or analytic value were considered to be primary contributors to the submental recording. Regardless of analysis approach, the primary contributions to the submental surface recording were the mylohyoid, anterior belly of the digastric, and the geniohyoid muscles. Contributions from the genioglossus and the platysma muscles were minimal. Contributions as a function of bolus volume and viscosity are also discussed.

Comparação da atividade elétrica dos músculos supra-hióideos durante a realização de diferentes exercícios linguais

“…The electromyographic signal captured in the submental region reflects the activity of the mylohyoid, geniohyoid and anterior digastric belly muscles, with small contribution of the genioglossus one (13) . There is a great intercorrelation among the suprahyoid muscles and it is not possible to capture, with surface electrodes, the electrical activity of only one of them.…”

“…Because it represents the activity of suprahyoid muscles, the electromyographic assessment of the submental region is commonly performed in the investigation of swallowing disorders (11,12) . In the submental electromyographic assessment, it is obtained the electrical activity of mylohyoid, anterior belly of the digastric and geniohyoid muscles (13) . Authors compared the electrical activity of the suprahyoid musculature in the tongue pressure exercises against the palate and head elevation from the supine position, and greater submental electrical activity was obtained during the pressure exercise of the tongue on the palate (11) .…”

Correlation between tongue pressure and electrical activity of the suprahyoid muscles

“…The examination captures the potentials of action generated in muscular contractions and allows the comparison of these values in relation to the amplitude and duration of the movement [21][22][23][24][25] . The suprahyoid muscles play an important role during swallowing because they are involved in the laryngeal elevation 26 . One study found that the increased tongue pressure against the palate coincided with increased suprahyoid muscle activity 26 , suggesting that tongue pressure exercises on the palate are indicated to strengthen not only the intrinsic musculature of the tongue, but also of the supra-hyoid muscles, improving airway protection during swallowing in patients with dysphagia.…”

“…The suprahyoid muscles play an important role during swallowing because they are involved in the laryngeal elevation 26 . One study found that the increased tongue pressure against the palate coincided with increased suprahyoid muscle activity 26 , suggesting that tongue pressure exercises on the palate are indicated to strengthen not only the intrinsic musculature of the tongue, but also of the supra-hyoid muscles, improving airway protection during swallowing in patients with dysphagia. Thus, some studies use surface EMG of the suprahyoid musculature to compare tongue strength training exercises used in the clinical practice of dysphagia 21,22,24 .…”

Mouthful Size Effects on Mastication Effort of Various Hydrocolloid Gels Used as Food Models

“…A larger size of sample often results in a longer period of oral processing, larger number of chewing, and higher EMG amplitude (Dantas and Dodds, 1990;Palmer et al, 1999;Miyawaki et al, 2000;Kohyama et al, 2005bKohyama et al, , 2007aWoda et al, 2006;Miyaoka et al, 2010;Ashida et al, 2010). We compared EMG variables during free eating of rice gruel (5 g and 10 g), and found that 10 g gruel exhibited significantly higher EMG variables corresponding to mastication time such as number of chews, chewing time, and total muscle activity than 5 g. However there were no significant differences between 5 g and 10 g in EMG variables per chew such as EMG amplitude, duration, muscle activity or muscle work, and chewing cycle (Kohyama and Nakayama, 2004).…”