The diastasis recti abdominis (DRA) is the separation of the right and left parts of the rectus abdominis muscle along the linea alba. In the literature you may also encounter the names rectus abdominis diastasis (RAD) or divarication of rectus abdominal muscles (DRAM). It occurs most frequently in pregnant women and after childbirth. Diastasis rectus abdominis muscle most commonly occurs in the umbilical region, but can also run above and below the umbilicus. The prevalence of DRA varies between study authors and ranges from 24% to about 70%.

Diastasis recti abdominis is not only a problem for women. DRA can also occur in men, but much less frequently. It most often appears after the age of 50, above the umbilicus. DRA in men is favoured by weight fluctuations, weight lifting and genetic factors – a family history of abdominal muscle weakness.

The separation of the linea alba in the DRA creates a space called the inter-recti distance (IRD). The authors variously report the physiological width of the linea alba. According to Beer et al. the physiological parameters for the width of thelin ea alba are up to 15 mm at the height of the sternocleidomastoid process, up to 22 mm at 3 cm above the umbilicus and up to 16 mm at 2 cm below the umbilicus. Furthermore, the width of the linea alba increases with age. The distance of the IRD decreases gradually with time in the postnatal period with individual variability.

How do I measure the distance between the separated parts of the rectus abdominis muscle? The oldest measurement, which is less precise but accessible to everyone and does not require specialised equipment, is palpation. The presence of a diastasis recti abdominis is indicated by an IRD distance of more than two finger widths. There are also more accurate methods. The width of the IRD can be measured with a tape measure, callipers, ultrasound, CT and MRI. Swedish recommendations suggest diagnosing DRA on clinical examination with a caliper or ruler. Imaging diagnosis by ultrasound or other imaging modalities should be performed when a concurrent umbilical or epigastric hernia or other cause of the patient’s symptoms cannot be excluded.

Antonina Kaczorowska

References:

1. Benjamin DR, van de Water ATM, Peiris CL. Effects of exercise on diastasis of the rectus abdominis muscle in the antenatal and postnatal periods: a systematic review. Physiotherapy. 2014;100(1):1-8.
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