2014 Volume 18 Issue 1 Pages 22-29
The Mendelsohn maneuver is one of the popular training methods for swallowing rehabilitation. This method, however, has several problems such as the difficulty of teaching and learning. Therefore, we have been developing a training system for assisting patients to perform laryngeal elevation by using visual biofeedback (BF) of the larynx movement. Its short-term training effects were already verified in our previous studies; in this study we verified its long-term effects using elderly volunteers. The subjects were 10 elderly males (70.3±4.6 y/o, mean±SE). Single laryngeal elevation (LE) was defined as keeping the larynx in higher positions for 5 s. One task comprises three sequential LE steps: 1) LE without BF, 2) LE with BF and 3) LE without BF, with a rest interval of 5–10 min. All subjects performed this task once a day for 5 straight days. Analysis parameters were 1) the amount of laryngeal elevation [mm], 2) duration of laryngeal elevation [s], 3) duration of 5 mm laryngeal elevation [s], and 4) duration of 10 mm laryngeal elevation [s]. Consequently, the amount of laryngeal elevation on the 5th day increased significantly from step 1 to step 2. Regarding the duration of the elevation, a significant increase was observed from step 1 to step 2 on the 1st day in parameters 2), 3) and 4) as well as on the 5th day in parameters 3) and 4). In comparison between the results on the 1st and 5th days, a significant increase was observed in step 2 in parameters 1) and 3). Results regarding the amount of laryngeal elevation demonstrated that all subjects could master elevating the larynx intentionally within 5 days. Results regarding the duration of the elevation demonstrated that a small amount of elevation could also be mastered within 5 days and that visual biofeedback was effective for prolonging the duration of the elevation of 5 mm or more. Elevation of 10 mm or more, however, could not necessarily be mastered, although the biofeedback effectively prolonged its duration. In conclusion, the proposed BF training was verified to be effective for increasing the amount of elevation as well as for sustaining the larynx in higher positions.
