Estimation of Muscle Activity Change under Different Bolus Conditions using Musculoskeletal Model of Swallowing

Swallowing, deglutition, is realized by highly coordinated activities of many nerves and muscles, but it is hard to observe directly due to intracorporal movement, and there is a limitation to the number of muscles that can be percutaneously measured. In addition, since there are few studies on the mechanical analysis of the swallowing movement, the detailed muscle activity pattern during swallowing has not yet been clarified. To tackle this problem from the viewpoint of biomechanics, we have been developing the musculoskeletal model of swallowing which can estimate the activities of swallowing-related muscles based on the movements of hyoid bone and thyroid cartilage. In this paper, we analyzed the activities of swallowing-related muscles under two different bolus conditions: bolus of water and nectar thickened liquid to investigate the effect of physical property of bolus in the activities of swallowing-related muscles.