PURPOSE: to investigate the influence of the habitual head posture, jaw and hyoid bone position on the supra and infrahyoid muscles activity of the muscles during swallowing of different food textures. METHOD: an observational, cross-sectional study, with women between 19 and 35 years, without myofunctional swallowing disorders. The craniocervical posture, position of the mandible and hyoid bone were evaluated by cephalometry. The electromyographic activity of the supra and infrahyoid muscles was collected during swallowing water, gelatin and cookie. RESULTS: sample of 16 women, mean age 24.19 ± 2.66 years. At rest, there were negative/moderate correlations between the electrical activity of the suprahyoid muscles with NSL/CVT (head position in relation to the cervical vertebrae) and NSL/OPT (head position in relation to the cervical spine) postural variables, and positive/moderate with the CVA angle (position of flexion/extension of the head). During swallowing the cookie, the activity of infrahyoid muscles showed a negative/moderate correlation with NSL/OPT angle. It was found higher electrical activity of the suprahyoid muscles during swallowing of all foods tested, and of the infrahyoid muscles at rest. There was difference on the muscle activity during swallowing of foods with different consistencies, which was higher with cookie compared to water and gelatin. CONCLUSION: the head hyperextension reflected in lower activity of the suprahyoid muscles at rest and of the infrahyoid muscles during swallowing. The consistency of food influenced the electrical activity of the suprahyoid and infrahyoid muscles, with greater muscle recruitment in swallowing solid food.
Posture; Deglutition; Electromyography; Cephalometry
