Larynx Elevation Training Using Visual-Biofeedback of Laryngeal Movement

<p>The Mendelsohn maneuver is a well-known exercise designed to treat reduced swallowing function caused by aging or dysphagia as an indirect therapy for rehabilitation. Although the maneuver is intended to improve laryngeal elevation of the hyoid bone, it is difficult for patients to understand what they are doing and to perform the elevation properly by themselves. Therefore, the authors developed a biofeedback (BF)-based training system for elderly people to elevate the larynx. The purpose of this study was to develop a training system, SFN/3A, and to evaluate its effectiveness in swallowing rehabilitation. The subjects were 10 healthy adult males (23.0±1.3 y/o, mean±SE) and 4 elderly males (89.8±5.5 y/o, mean±SE) in a healthcare facility for the elderly. Healthy subjects were divided into two groups, one with biofeedback and the other without biofeedback. Healthy subjects with BF and elderly ones carried out the laryngeal elevation task in the following sequence: 1) without BF, 2) with BF and 3) without BF, while healthy people without BF carried out the same task without biofeedback. Each subject was required to keep the laryngeal elevated position for 5 seconds per trial. The parameters for analysis were: 1) amount of laryngeal elevation [mm], 2) duration of laryngeal elevation [s] and 3) duration of high elevation [s]. The amount of laryngeal elevation of the healthy group with BF and without BF tended to increase and exhibited no significant change, respectively, throughout the steps. Duration of laryngeal elevation did not change significantly throughout the steps in the healthy groups, while duration of high elevation tended to increase in the same groups. Thus, we considered that healthy subjects could master laryngeal elevation easily thanks to the biofeedback training. In the elderly people, all the parameters tended to increase or increased significantly between steps 1 and 2, while duration of high elevation decreased significantly between steps 2 and 3. Therefore, we considered that the elderly people could not master the elevation only by means of this 5-minute training. In conclusion, the biofeedback training system was verified to be effective for both healthy and elderly groups, but elderly people should take this training repeatedly to master the elevation of the larynx.</p>