Using Shear Wave Elastography for Morphofunctional Analysis of Abdominal Muscles: A Scoping Review

This scoping review evaluates current research on the use of Shear Wave Elastography (SWE) in analyzing abdominal muscles, specifically the transversus abdominis, oblique muscles, and rectus abdominis. SWE is an advanced ultrasound technique that assesses tissue mechanical properties, offering detailed insights into tissue stiffness. Following PRISMA-ScR guidelines, the review included peer-reviewed studies on SWE of abdominal muscles in adults, excluding case studies, reviews, and studies on postmortem subjects or on non-abdominal tissues. A comprehensive search was conducted in PubMed, Medline, SPORTDiscus, Scopus, Web of Science, and Cinahl in April 2024, followed by a rigorous selection process involving two independent reviewers and a third reviewer to resolve discrepancies. Data extraction focused on study design, population characteristics, SWE methodology, and outcomes. The review included 27 studies. Out of these 27 studies, 11 were selected. The stiffness of the transversus abdominis at rest showed great variability, with propagation speeds ranging from 1.45 m/s to 2.3 m/s, being lower in healthy individuals compared to those with pathologies. The resting SWE values for the obliques were more homogeneous: between 1.40 and 1.54 m/s for the internal oblique and from 1.79 to 1.89 m/s for the external oblique in healthy adults, which increased in active individuals. For the rectus abdominis, the resting SWE values ranged from 1.61 m/s in women to 2.07 m/s in active young individuals. Although SWE is a relatively new technique for tissue assessment and there is no standard reference for the values obtained, its use in the study of abdominal musculature is promising, offering a non-invasive view of muscle stiffness. This review has identified several limitations, such as the lack of standardization in methodology, variability in the populations studied, and technical considerations that affect the measurements accuracy.