The Effects of a Short-Term Isometric Exercise Program Targeting Tongue, Jaw, and Trunk Muscles on Muscle Strength and Synergistic Relationships in Post-Stroke Patients: A Single-Group Pre-Post Study

Background: This study aimed to investigate the effects of a short-term tongue-jaw-back isometric exercise program on these muscle groups and their interrelationships in the post-stroke period. Methods: Twelve post-stroke patients were included in the study. A 14-day exercise program, consisting of two daily sessions targeting the tongue, jaw, and back muscles, was administered. Anterior and posterior tongue muscles, jaw muscles, and back muscle strength were assessed before and after the exercise program. Tongue pressure was measured using the Iowa Oral Performance Instrument (IOPI), chewing strength with a hand-held dynamometer, and back strength with a stabilizing pressure biofeedback unit. Results: After the 14-day isometric exercise program, anterior tongue strength (p = 0.025), posterior tongue strength (p = 0.021), and back muscle strength (p = 0.005) showed significant increases compared to pre-treatment values. No significant change was observed in jaw strength (p = 0.475). Spearman correlation analysis revealed no significant relationships between tongue muscles and jaw or back muscles before treatment, and simple correlations after treatment also did not reach significance. However, partial correlation analysis showed that the relationship between tongue muscles was significantly influenced by jaw strength (p = 0.040) and back strength (p = 0.038) after the intervention. Conclusions: Short-term isometric exercises targeting tongue, jaw, and back muscles in post-stroke patients effectively increased tongue and back muscle strength and enhanced the synergistic relationship among these muscle groups. Trial registration: This study was retrospectively registered with ClinicalTrials.gov on 2025-11-21 (ID: NCT07261462).