To Crunch or Not to Crunch? DRA and Abdominal Exercise


Diastasis Rectus Abdominis (DRA) is a widening of the gap between the two sides of the rectus abdominis muscle (RA) during and after pregnancy. The RA is the long muscle running from the rib cage to the pelvis that forms the coveted “six pack” that so many fitness enthusiasts strive for. The two sides of the RA are delineated by the linea alba, a line of fascial connective tissue that runs the length of the muscle.

During pregnancy, as the fetus grows and the mother’s belly swells, the linea alba stretches, allowing the RA to separate to make room for the baby. In most women, the gap between the two sides of the RA gradually closes again over the course of several weeks postpartum. However, in some women, the linea alba remains stretched, and the gap between the two sides of the RA is visible long after the body has recovered from childbirth.

Closing the Gap

In many cases, DRA is a cosmetic issue that does not interfere with normal function of the trunk and pelvis, although in severe cases there may be some functional abnormalities. In either case, many women with DRA seek to resolve the issue, often turning to abdominal exercises in hopes of closing the gap.

And therein lies the controversy: To crunch or not to crunch?

There is a growing consensus among physical therapists and others who work with DRA sufferers that crunches increase intra-abdominal pressure, thereby causing the RA muscles to pull against the linea alba during a crunch and widening the gap. It seems to follow then that crunches are bad, if the goal in treatment is to close the gap rather then widen it.

However, the real goal is to improve the integrity of the linea alba, so that it binds the two halves of the RA closer together. The nature of fascia is to respond to overload in a way similar to muscle tissue — that is to become denser and stronger in adaptation to the demands being placed on it.

To quote an article by Schlepp and Muller (2013), “A recognized characteristic of connective tissue is its impressive adaptability: when regularly put under increasing yet physiological strain, the inherent fibroblasts adjust their matrix remodeling activity such that the tissue architecture better meets demand.”

So we have to ask ourselves, do crunches really do more harm than good in treatment protocols geared to closing the gap?

The answer may lie in technique. During dynamic activity, a single muscle does not act independently, but rather works in conjunction with other muscles in a coordinated series of contractions. Women can be coached to execute crunches in a way that optimizes muscle recruitment and minimizes intra-abdominal pressure.

Crunches may not be appropriate in the early stages of postpartum treatment. However, they may be an effective exercise when introduced at the appropriate stage of a progressive exercise program. A supervised program with a therapist specializing in DRA is recommended.

Prenatal and Postpartum Treatment in NYC

If you are expecting or have recently given birth, achieving and maintaining optimal fitness will help you deal with the changes your body experiences through the various stages of pregnancy and childbirth. The specialists at NYDNRehab can create an exercise program that is right for you, at any stage. Contact NYDNRehab today, and let us help you get your baby body in the best shape ever.


Schleip, Robert, and Divo Gitta Müller. “Training principles for fascial connective tissues: scientific foundation and suggested practical applications.” Journal of bodywork and movement therapies 17.1 (2013): 103-115.


In this instance, an athlete was originally diagnosed with minor quadriceps muscle strain and was treated for four weeks, with unsatisfactory results. When he came to our clinic, the muscle was not healing, and the patients’ muscle tissue had already begun to atrophy.

Upon examination using MSUS, we discovered that he had a full muscle thickness tear that had been overlooked by his previous provider. To mitigate damage and promote healing, surgery should have been performed immediately after the injury occurred. Because of misdiagnosis and inappropriate treatment, the patient now has permanent damage that cannot be corrected.

The most important advantage of Ultrasound over MRI imaging is its ability to zero in on the symptomatic region and obtain imaging, with active participation and feedback from the patient. Using dynamic MSUS, we can see what happens when patients contract their muscles, something that cannot be done with MRI. From a diagnostic perspective, this interaction is invaluable.

Dynamic ultrasonography examination demonstrating
the full thickness tear and already occurring muscle atrophy
due to misdiagnosis and not referring the patient
to proper diagnostic workup

Demonstration of how very small muscle defect is made and revealed
to be a complete tear with muscle contraction
under diagnostic sonography (not possible with MRI)


Complete tear of rectus femoris
with large hematoma (blood)


Separation of muscle ends due to tear elicited
on dynamic sonography examination

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