Separated Rectus Abdominis (Diastasis recti) – are we rehabilitating them correctly?

Those therapists amongst you will know about Diastasis recti, a separation between the left and right side of the rectus abdominus muscle, which covers the front surface of the abdominal area. It is another name for the more commonly described Split Rectus Abdominus. It is caused by pregnancy and the rectus muscle being stretched by the baby in the uterus. It is most common in the later trimesters and more so with multiple births or repeated pregnancies.

A diastasis recti looks like a ridge, which runs down the middle of the abdominals. It stretches from the sternum to the navel and increases with abdominal muscle contraction. In the later part of pregnancy, the top of the pregnant uterus is often seen bulging out of the abdominal wall when rectus is engaged. An outline of parts of the unborn baby may be seen in some severe cases.

Post natally you can check if your client/patient has Diastasis recti by laying them supine with knees bent (crook lying) and get them to raise their heads. You commonly see a central ridge protrude in the centre of Rectus Abdominis and if you palpate above the navel you should feel a soft gap between two hard muscles. Measure the space of the gap using your fingers (this is called a Rec Check). If the gap is greater than two finger widths, your client/patient may be suffering from separated muscles.

No treatment as such will help pregnant women with this condition, although exercise may help, but there is limited evidence that exercise will resolve the problem. However postnatally conventional wisdom suggests that after any discomfort has settled it is reasonable to start some light abdominal work, but do not work the obliques initially. Understanding their origin and insertions reveals any oblique contraction will most likely exaggerate the split of Rectus. Conventional wisdom suggests to start with pelvic floor work and stabilising work using Transversus Abdominis (Trans Abs) with the pelvis in the correct position, then do co-activation work with pelvic floor then progress to try and shorten Rectus by doing inner range work. The production of relaxin (a hormone that is secreted in abundance when pregnant) effects the collagen make up in the linae alba (the central tendon in rectus abdominus) and may be a cause of the diastasis. As soon as the placenta is delivered the increased secretion of relaxin reduces to normal, but the effects can last for up to 5 months and breast feeding will keep it higher than normal until your client/patient has stopped. This may affect how quickly the Diastasis recti will reduce.

Please be careful while working Transversus Abdominis though. While conventional wisdom is sometimes right, it sometimes isn’t, let’s challenge it now. If you look at the origin and insertion of Transversus Abdominis and consider its function, logically when it contracts it will pull the rectus apart further, much the same as contracting the obliques would. There is no evidence to suggest that doing Trans Abs work is the right thing to do, its just something that we all do, without it seems, much thought as to why. Just think, if the Trans Abs inserts into the aponeurosis of rectus (anteriorly below the navel and posteriorly above the navel), any Trans Abs contraction should pull the rectus apart further. So why do we work Trans Abs initially with a diastasis recti?

Actually we’ve measured the split of rectus using Ultrasound scanning and it does separate further when Trans Abs is engaged. I am collaborating with a colleague, Mark Maybury, who is an Extended Scope Physiotherapist specializing in Ultrasound scanning, and we plan to do a paper on this – to challenge conventional wisdom in this field. We hope to have it completed in the next few months, please come back and see what we find, I’ll put the paper here when it’s completed.

What is your experience with this condition?