Kinematic Measurements of Swallowing by Ultrasound: A Scoping Review

Ultrasound (US) is a non-invasive method used to study the kinematics of the swallowing function. Kinematic measurements are reported in studies evaluating swallowing using US, but there is no standardization. The aim of this scoping review was to identify and characterize the kinematic measurements of swallowing obtained by ultrasound. We followed the methodological recommendations of the Joanna Briggs Institute (JBI) and the reporting guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-extension for scoping reviews (PRISMA-ScR). The research question followed the acronym PCC (population, concept, and context). Seven databases and gray literature were searched. Studies were selected using a blind, paired, and independent method. Data were extracted using a standardized tool. There were 2591 studies and 42 were eligible. Most studies had samples of less than 30 participants and mostly included healthy young adults and older people. The swallowing tasks during the assessments were not standardized. The most commonly studied measures were hyoid displacement and tongue movement during swallowing. However, there is no consensus between studies on the definition of the measures and the procedures for ultrasound assessment, including image acquisition and analysis.