Effect of Multidirectional Chin Tuck Against Resistance Exercise on Oropharyngeal Muscles and Swallowing Function in Subacute Stroke Patients With Dysphagia: A Randomised Controlled Trial

Background: The chin tuck against resistance (CTAR) exercise is a rehabilitative technique for stroke patients with dysphagia. However, related clinical evidence remains unclear, and methodological improvements in this therapy are required. Objective: This study aimed to investigate the effects of the modified CTAR exercise on swallowing-related muscles and swallowing function in stroke patients with dysphagia. Methods: Stroke patients with dysphagia (n = 30) were randomly assigned to a multidirectional CTAR exercise group (md-CTAR exercise group) and a vertical-directional (vd-CTAR exercise group) (n = 15 per group). The md-CTAR exercise group performed exercises in the left and right diagonal and vertical directions using a prototype device. The vd-CTAR group performed only vertical exercises. Both groups performed the exercises for 5 days each week over a period of 6 weeks. Primary outcome measures included tongue strength, thickness and suprahyoid muscle activation. Secondary outcome measures included the Videofluoroscopic Dysphagia Scale (VDS) and Penetration-Aspiration Scale (PAS) based on videofluoroscopic study. Results: The md-CTAR group exhibited significantly higher maximal tongue strength, thickness and suprahyoid muscle activity than the vd-CTAR group (p < 0.05, all), as well as a significant decrease in the oral and pharyngeal phase of the VDS score (p = 0.048 and 0.041) and PAS compared to the vd-CTAR group (p = 0.047). Conclusion: md-CTAR exercise is more effective than vd-CTAR exercise in improving the oropharyngeal muscles and swallowing function in stroke patients with dysphagia. Therefore, the md-CTAR exercise is recommended as a modified therapeutic exercise for dysphagia rehabilitation.