Shear-wave elastography assessment of the linea alba mechanical properties in individuals with obesity versus normal-weight: A pilot study

BACKGROUND: Diastasis recti abdominis (DRA) is characterized by a widened linea alba, but its pathophysiology may involve complex biomechanical failure. This pilot study utilized shear-wave elastography (SWE) to characterize the mechanical properties of the abdominal wall in healthy adults and investigate the influence of obesity on DRA presentation. MATERIALS AND METHODS: The study was conducted on a group of 10 healthy adult volunteers. All participants underwent ultrasonographic assessment. Morphological measurements and SWE of the linea alba, rectus sheaths, and lateral fasciae were performed at rest and during three maneuvers: Valsalva, curl-up, and side plank. RESULTS: Four participants had DRA. A divergent biomechanical response was observed: during an isolated curl-up, the linea alba stiffened in obese individuals with DRA but softened in non-obese individuals. A visible epigastric bulge was universally linked to DRA, but its manifestation depended on body habitus and the type of muscle activation. Obese individuals exhibited bulging during global maneuvers (Valsalva, side plank), whereas non-obese individuals showed bulging only during the curl-up. CONCLUSION: Obesity fundamentally alters the abdominal wall’s response to load, suggesting a dual pathophysiology for DRA-related bulging. These preliminary findings highlight that management strategies, including physical therapy, may need to be tailored based on patient body habitus.