Effects of aging and bolus characteristics on laryngeal movement during oropharyngeal swallowing

PURPOSE: Swallowing is a complex sensorimotor process that dynamically adapts to bolus characteristics and physiological variations. Age-related neuromuscular changes in older adults can alter swallowing function, potentially compromising swallowing safety and efficiency. This study investigated age-related differences in oropharyngeal swallowing by analyzing laryngeal displacement and swallowing sounds using a force-sensitive resistor (FSR) sensor and cervical auscultation. METHODS: Six swallowing tasks with varying bolus volumes and viscosities were assessed across 16 healthy young adults and 12 healthy older adults. A two-way mixed-model repeated-measures analysis of variance was conducted to examine differences in temporal and amplitude parameters of the acoustic and FSR signals. RESULTS: FSR signals analysis revealed that increasing bolus volumes shorten the duration of laryngeal activation in young adults, whereas it produced significantly prolonged laryngeal activation in older adults. Additionally, aging significantly increased the overall duration of laryngeal movement during swallowing, particularly during the relaxation phase. No significant gender effects were observed in any of the analyses. CONCLUSIONS: In older adults, slower laryngeal movement during the oropharyngeal phase of swallowing indicates reduced muscular capacity and diminished coordination between bolus transit and laryngeal kinematics. These age-related neuromuscular changes may compromise swallowing efficiency and airway protection, thereby increasing susceptibility to dysphagia-related complications. Future research should focus on developing automated detection algorithms and multimodal datasets that combine physiological measurements and swallowing imaging to objectively link sensor-derived features to physiological swallowing events.