Pilot kinematic study of swallowing in healthy adults: age-related, individualised, and lateralised patterns of bolus trajectories.

BACKGROUND

Swallowing function may undergo subtle changes with age, even in asymptomatic adults. However, objective and reproducible metrics for characterising normal swallowing motion remain limited.

AIMS/

OBJECTIVES

This pilot study aimed to quantify the spatiotemporal trajectory of the bolus centre of mass (CoM) during swallowing in healthy adults and explore its potential as a kinematic marker for identifying individualised and age-associated patterns.

MATERIALS AND

METHODS

Thirteen healthy adults (aged 26-62 years) underwent videofluoroscopic swallowing studies using contrast-enhanced liquid boluses. Bolus CoMs were tracked throughout the oropharyngeal phase. Multiple swallows per participant were analysed to assess intra-individual consistency. K-means clustering and silhouette analysis were applied to the CoM trajectory data to evaluate pattern reproducibility and explore potential age-related differences.

RESULTS

CoM trajectories were highly consistent within individuals (silhouette score = 0.718). Clustering revealed age-related patterns: older participants exhibited more centralised trajectories, whereas younger participants demonstrated more lateralised movement. Additional differences in bolus descent and pharyngeal coordination existed between age groups.

CONCLUSIONS AND SIGNIFICANCE: Bolus CoM trajectory analysis is a feasible and reproducible approach for assessing swallowing kinematics. These trajectories may represent individualised motor signatures and could help identify subtle, age-related changes. The findings underscore the need for personalised dysphagia assessment and rehabilitation strategies.