The Influence of Visual Input on Electromyographic Activity and Patterns of Masticatory and Cervical Spine Muscles in Emmetropic Caucasian Subjects by Gender

Abstract

(1) Background: The objective of the research was to analyze the change of visual input on electromyographic activity and patterns of masticatory and cervical spine muscles in emmetropic Caucasian subjects by gender. Supposedly, visual input should not influence activity and electromyographic patterns of masticatory and cervical spine muscles in emmetropic Caucasian subjects by gender. (2) Methods: After applying the inclusion criteria, 50 emmetropic Caucasian subjects were included in the study. Four muscle pairs were analyzed: the temporalis muscle (TA), the masseter muscle (MM), the digastric muscle (DA), and the sternocleidomastoid muscle (SCM), during resting and functional activity. (3) Results: It was observed that there were no significant statistical differences in activity and bioelectrical patterns between open and closed eyes in women and men, with the exception of clenching on dental cotton rollers in DA-left and DA mean between tests in women. The observed statistical results had a small effect size, successively equal to 0.32 and 0.29. (4) Conclusions: Changes in the influence of visual input do not affect electromyographic activity and patterns of masticatory and cervical spine muscles in emmetropic Caucasian women and men.

Study protocol: Accommodative effects on the musculoskeletal system

“…Moreover, responses of the muscular system were observed depending on visual acuity [32]. No changes in muscle activity were observed in emmetropic subjects depending on visual input [12,15]. Based on these observations, we suggest that there will be an increase in resting activity and a decrease in the functional activity of the studied muscles after accommodative paralysis in both study groups.…”

“…A 5-second maximum contraction will be performed, with a 2-second rest between, and then the contraction will be repeated [40]. Electromyographic activity will be recorded in conditions: at rest (10 s), during maximal voluntary contraction (as hard as possible; 3 × 3 s, 2 s rest between); addition, one additional procedure will be applied for the masticatory muscles during maximal voluntary clenching on dental cotton rollers (as hard as possible; 3 × 3 s, 2 s rest between) [15,41] (Fig 1).…”

“…In addition, several studies have observed differences in muscle activity during open-eye and closed-eye testing in people with myopia [12][13][14]. Such differences were not seen in emmetropic subjects [12,15]. So far, it has been hypothesized to be explained by the vestibuloocular reflex and the connection to the trigeminal nuclei, which indirectly respond to impulses transmitted from other cranial nerves [16,17].…”