2025 Volume 29 Issue 1 Pages 3-10
The purpose of this study was to investigate the effects of different training methods for the suprahyoid muscles on the amount of muscle activity of the swallowing-related muscles in a training task utilizing jaw opening movements and head and neck flexion.
Method: Thirty-three healthy adults (20 males, 13 females; mean age 33.8±6.9 years) were included in the study. The method consisted of four types of training exercises: jaw opening exercise (JOE), resistive jaw opening exercise (RJOE), head lift exercise (HLE), and forehead exercise for suprahyoid muscles. The muscle activities of the suprahyoid and infrahyoid muscles, and sternocleidomastoid muscles were recorded with a surface electromyograph during the four training exercises. The 5-second period from the start to the end of each training task was used as the analysis interval, and the maximum and average amplitude values were calculated from the EMG of each muscle under test.
Results: The RJOE exhibited the highest maximum and mean amplitude values for the suprahyoid muscles, with no significant difference between the RJOE and the HLE, but there was a significant difference between the RJOE and the swallowing forehead exercises. HLE had the highest maximum and mean amplitude values for the suprahyoid muscles and sternocleidomastoid muscles, with significant differences between RJOE and JOE.
Conclusions: In training methods utilizing jaw opening exercises (JOE, RJOE), muscle activity of the suprahyoid muscles was high, while that of the infrahyoid muscles and sternocleidomastoid muscles were low. In training methods involving head and neck flexion (HLE, swallowing forehead exercises), not only the suprahyoid and infrahyoid muscles but also the sternocleidomastoid muscles were more active. Because the activities of the suprahyoid and infrahyoid muscles, and sternocleidomastoid muscles differ depending on the training method, effective swallowing rehabilitation can be provided by selecting or combining training methods that utilize jaw opening and head and neck flexion exercises, depending on the dysphagia status of the patient when strength training is performed on the swallowing-related muscles. This will enable the provision of effective swallowing rehabilitation.
