Diastasis recti abdominis (DRA) is traditionally defined as a widening of the linea alba, with a separation exceeding 20 mm on ultrasound serving as the common diagnostic criterion. For years, it was viewed largely as a cosmetic issue rather than a functional problem. However, emerging evidence suggests that DRA may involve complex biomechanical failure beyond simple anatomical separation, and the influence of obesity on abdominal wall mechanics remains poorly understood.

The study included 10 healthy adults (4 women, 6 men; mean age 43.7 years). Three participants were obese (BMI ≥ 30), and four met the ultrasound criteria for DRA (linea alba width > 20 mm). All participants with DRA showed a visible or palpable epigastric bulge in at least one body position, but the pattern of bulging differed by body type. Obese individuals exhibited bulging during global maneuvers such as the Valsalva and side plank, whereas non-obese individuals showed bulging only during a curl-up.

Shear-wave elastography captured the dynamic mechanical response of the abdominal wall across six sites, including the linea alba, its junction with the rectus abdominis, the anterior and posterior rectus sheaths, the external oblique fascia, and the transversalis fascia. During a curl-up, the linea alba softened in non-obese individuals but stiffened in obese individuals with DRA. During the Valsalva maneuver, tension roughly doubled at all measured points in both groups, but the increase was significantly greater in the external oblique and transversalis fascia of obese individuals (Figure 1). The linea alba width ranged from 13 to 70 mm (mean 33.1 mm), and morphological measurements were also recorded.

This study moves beyond simple anatomical measurements to assess the dynamic mechanical properties of the abdominal wall in real time. This study uses shear-wave elastography to demonstrate that the biomechanical response of the linea alba to muscle activation differs fundamentally between obese and non-obese individuals—pointing to a dual pathophysiology for DRA-related bulging that has not been well characterized in previous research.

The findings suggest that management strategies for DRA—including physical therapy—may need to be tailored based on patient body habitus. For obese individuals, weight reduction may be a more appropriate first step than exercise alone, given the fundamentally different mechanical environment of the abdominal wall in this population. The work titled “Shear-wave elastography assessment of the linea alba mechanical properties in individuals with obesity versus normal-weight: A pilot study” was published in International Journal of Abdominal Wall and Hernia Surgery (published on 18-Apr-2026).
DOI: 10.4103/ijawhs.ijawhs_125_25