Ultrasonographic and Elastographic Markers of Muscle Changes Associated with Post-Stroke Spasticity: A Systematic...

Background/Objectives: Clinical assessment of post-stroke spasticity may not fully distinguish neural contributions from structural and mechanical muscle changes. This systematic review examined associations between B-mode ultrasonographic and elastography-derived muscle parameters and the presence or severity of post-stroke spasticity. Methods: PubMed, Scopus, and Web of Science Core Collection were searched from inception to 18 July 2026. Eligible studies investigated ultrasound-derived skeletal muscle parameters in adults after stroke in relation to spasticity status or severity. Methodological quality was assessed using the Joanna Briggs Institute checklist, and certainty of evidence was evaluated using the GRADE approach. Findings were synthesized narratively because of substantial heterogeneity. Results: Eighteen studies were included, six contributing B-mode structural data and twelve elastography-derived mechanical data. B-mode findings were inconsistent across muscles and measurement conditions. Elastography more frequently identified increased stiffness-related parameters in paretic or spastic muscles, although associations with clinical spasticity severity were not consistently observed. The certainty of evidence was very low across the assessed outcome domains, reflecting methodological limitations, small sample sizes, and inconsistency in the reported associations. Conclusions: B-mode ultrasound and elastography provide complementary information on muscle changes after stroke, but neither can currently serve as a stand-alone measure of spasticity severity. Elastography may help characterize the mechanical component of post-stroke hypertonia alongside clinical examination. Larger, standardized longitudinal studies are needed to establish the clinical utility of these techniques.