Effects of Tongue-Hold Swallows on Suprahyoid Muscle Activation According to the Relative Tongue Protrusion Length in the Elderly Individuals.

Abstract

This study investigated differences in suprahyoid muscle activity in elderly adults during tongue-hold swallowing (THS) according to tongue protrusion length to determine the most effective tongue protrusion length during THS. A total of 52 healthy participants (34 females and 18 males) aged 69-92years were included. Changes in suprahyoid muscle activation during normal swallowing and THS with 1/3rd and 2/3rd tongue protrusions using surface electromyography were observed. Suprahyoid muscle activation significantly increased with the increasing tongue protrusion length (p < 0.05). Depending on the responses of the participants based on tongue protrusion length, participants were categorized into the increase group [increased suprahyoid muscle activity with tongue protrusion, n = 36 (1/3rd THS compared to normal swallowing) or 38 (2/3rd THS compared to normal swallowing)] or decrease group [decreased suprahyoid muscle activity with tongue protrusion, n = 16 (1/3rd THS compared to normal swallowing) or 14 (2/3rd THS compared to normal swallowing)]. The functional reserve of the increase group was significantly higher than that of the decrease group (p < 0.05). Many elderly people were found to have increased activation of the suprahyoid muscle during THS; however, others showed the opposite. Therefore, it is necessary to confirm the degree of suprahyoid muscle activation during THS so that the patient can perform the exercise at the tongue protrusion length that can maximize the effect of the exercise. For individuals who cannot overcome even a small amount of tongue protrusion (e.g., 1/3rd MTPL), replacing THS with another exercise may be considered.