Abdominal muscle separation (also known as ‘diastasis recti’ or ‘rectus diastasis’) refers to separation of the six-pack (rectus abdominis) muscles. During pregnancy, the growing uterus stretches the tissue (called the linea alba) between the six-pack muscles. In some women, this tissue does not fully recover, resulting in muscle separation. This causes the belly to protrude in the middle, especially when straining or sitting up. It can occur after C-section or vaginal delivery (often searched as diastasis recti after C-section). The bulge from diastasis recti is a generalised midline bulge rather than a localised shelf, and is sometimes described by patients as a “still-pregnant” or “rounded” abdomen.
In severe cases, women experience back pain or poor posture because the abdominal muscles aren’t providing the normal support. Physiotherapy can improve core function and sometimes reduce the separation, but significant diastasis often requires surgical repair for definitive correction.
Features suggestive of diastasis recti include:
- A generalised abdominal bulge, often more noticeable when sitting up or straining
- A feeling of reduced core strength
- A visible or palpable gap in the middle of the abdomen
- The bulge is not confined to the C-section scar area
Diastasis recti contributes to abdominal prominence but does not, on its own, cause a localised shelf at the scar. Many women with diastasis have no visible shelf, and many shelves occur without significant muscle separation.
To read more about abdominal muscle separation (diastasis recti) and how it is assessed in Sydney, see our Abdominoplasty (Tummy Tuck) page.
While muscle separation can contribute to abdominal prominence, it does not, on its own, explain a localised C-section shelf.
A C-Section Shelf Is Not Caused by Muscle Separation Alone
While diastasis recti can contribute to a generalised abdominal bulge, it does not typically produce a sharp, localised overhang directly above a C-section scar. Muscle separation affects the midline of the abdomen and becomes more apparent with straining or sitting up, whereas a shelf is defined by a fixed lower boundary at the scar itself.
