“Testing” for Diastasis Recti: Part 1

While assessing postpartum clients for Diastasis Recti is standard practice, the check itself is anything but clear and simple. There are many variables that can influence the results and, therefore, can frustrate those who are looking to this test to provide precise measurements and resulting action steps.

This article aims to highlight some of the variables that can influence the assessment process and provides guidance on how you can better control for them to improve your testing accuracy. In Part 2, we will focus on the various ways to interpret, and take action, on your findings.

Before You Read On, Get the Basics

This article assumes you have a basic understanding of what Diastasis Recti is, the factors that cause it, and how to perform the assessment.  Not familiar with this?  Start here with Diastasis Recti: What You Need to Know. 

DR Testing: What Are We Checking For?

One reason that DR is a bit tricky to check for is that there is actually no international consensus on how to define DR in the first place. Traditionally, DR has been defined simply by the inter-recti distance (IRD). This is how wide the distance is between the medial borders of the left and right rectus muscles. Studies on DR have come up with a range for IRD from 1.5 cm to 2.7 cm (1 – 3). PROnatal Fitness uses a 2.7 cm IRD (or the equivalent of about 2 finger-widths) because it is the most well-accepted at this point.  In other words, a gap of 2.7 cm or greater is considered DR, but anything less is not.

While the above may seem simple enough, it gets a bit more complex.  Not only are there several variables that can influence the width you measure, but — if you’ve taken the PROnatal Fitness Education — you know that we discuss how newer research (led by preeminent physical therapist Diane Lee) is revealing that depth of separation can actually be a more telling indicator of DR severity. In other words, when you palpate the linea alba tissue (press down into the gap), how “taut” (or not) does that tissue feel?  In general, the more tension the linea alba has (as evidenced by a “springier” feel that prevents your fingers from sinking deep into the abdomen), the better the structural integrity of the deep core (4).  So, if you are pressing on the gap and it feels shallow, taut, and springy, this is a good sign. However, if the gap feels “soft and squishy” enabling you to sink your fingers down into the gap, this is a sign of a more compromised core.  Unfortunately, there is no objective measurement criteria for the depth measurement like there is for the IRD of 2.7 cm for the width measurement.  It’s really up to your own perception, which does become more accurate the more experience you have testing multiple clients.

So, we’ve established that we are supposed to check for width and depth, but that there is also a great deal of variability in the results we may get from these measurements.  Now let’s discuss the factors that influence these tests to help you better control your controllables and get more accurate findings.

Variables That Influence the DR Check

Before discussing the variables, make sure you are familiar with our general guidance on How to Check a Client for DR. We hear questions like the below all the time:

  • “How come I check the gap one day and it’s just over 1 finger-width, and the next day it’s nearly 3 fingers wide?” 
  • “The depth of the gap seems to change as well.  The first time I checked, it seemed softer and more yielding, but then I checked again and it seemed more taut.”
  • “I checked my client for DR and measured her gap at 2 finger-widths, but another professional checked her as well and told her it was only 1 finger-width.”

This is because there are many variables that will impact both the width and the depth you measure, such as how large your fingers are, how hard you press down, how high your client lifts her head, how nervous she is at the time, what she ate beforehand, and how she breathes during the assessment.  Even the fact that she is lying in supine for the DR assessment (which means her stomach contents are being pulled down away from her anterior abdominal wall) will show a different result than if you were to assess her in a vertical trunk position.  While you can’t control every single variable, there are variables you CAN control that will improve the accuracy of your findings:

  • Be consistent with how YOU perform the assessment: While you can’t control the fact that you will have different finger sizes if you’re a 120 lb petite female trainer than if you’re a 220 lb male trainer, you CAN control how consistent you are in your assessments.  Make sure that your procedures (how you check, how hard you press down, etc) and your instructions to your clients (your step-by-step guidance on what to do) are consistent — from one client to the next, and with the same client from one time to the next.
  • Create a comfortable assessment environment: Some clients may feel anxious at the idea of assessing DR, especially in the presence of a new, unfamiliar trainer.  They may also carry tension for a variety of reasons unrelated to the assessment itself. This can impact the tension you assess in their tissues.  The more you can create a supportive, positive environment to ease their nerves and allay fears, the less tension they are likely to demonstrate. One of the ways to do this is to explain that a degree of DR is actually a normal and natural part of pregnancy, and not a failure on their part for having it.  Another way to ease tension is to be calm about your assessment findings, whatever they may be.
  • Ensure she does not feel bloated: Bloating pushes abdominal contents forward, thereby widening the gap. There are a variety of reasons someone may be bloated, but what a client ate — and how soon she ate — prior to the assessment could potentially affect her findings. Ideally, try not to check within an hour of her eating a full meal, and ask if she feels any bloating as well.
  • Instruct your client to exhale JUST BEFORE she raises her head: The way your client breathes during the assessment can result in a different feel of the linea alba tension (depth). A preparatory exhale BEFORE the head rises can create more engagement of the fascia so that it displays its greatest tensile properties (basically the “best” tension the linea alba is able to produce) as opposed to the client exhaling at the same time or after the head rises. Therefore, make sure instruct your client to exhale just prior to raising her head.
  • Instruct her to only lift her head about 1 inch: Raising the head and shoulders too much can cause the left and right rectus muscles to come closer together, giving a false sense of closure. Therefore, you want to assess at the point where you FIRST feel the rectus contraction. Typically, placing your fingers at your client’s sternum when she is at rest and then cueing her to lift her head only about 1″ helps to achieve this.
  • Assess from sternum to 2 inches below navel: Gap width will almost always vary from the top to bottom linea alba attachment points so it’s important to assess the full length.  Begin at the very top (sternum) and check all the way down until about 2″ below the navel.  We make our assessments on the widest and deepest areas. Typically, the widest separation is at the navel, but not always, so be sure to check the full range. This may take a few repetitions of allowing your client to rest for a second, then lift her head again.
  • Check gap at rest as well: This is not something we show in our video demonstration, but given the variability in gap size and tension that can result from variations in head lifts and breathing, it’s also a good idea to get a point of comparison when she is at rest.  This may be more difficult to do, especially if she has excess belly fat, but if possible, it’s good to have this as a comparison.
  • Assess in different conditions: The supine assessment is just a starting point to get a sense of DR in a passive context, but it is critical to notice how other conditions (trunk position, gravity, intensity, etc.) may help reveal DR. So, constantly assess your clients during their workouts as well.  Having them lift heavier loads often provides great insight, as this elevates intra-abdominal pressure (IAP) and enables you to assess their ability to manage higher it.

NOTE: For clients with excess belly fat, the supine assessment may be too difficult for you to perform. So, you will have to rely solely on observing your client during her movements and also ask questions about pain or discomfort to make the best judgment. 

Interpreting Your Findings

Once you have performed the assessment to the best of your ability (controlling for the variables above), what do you do with the results? How do you know what actions to take with your clients to help them make the most progress (and feel good about that progress)?  This is what we will discuss in Part 2, so stay tuned next month for that!

Additional Resources to Continue Your Understanding

What is a Normal Diastasis?” by Julie Wiebe, P.T.

Diastasis Overview” with Antony Lo, P.T. & Marika Hart, P.T. The Women’s Health Podcast, episode 002: August 14, 2018.


  1. Beer, G.M., Schuster, A., Seifert, B., Manestar, M., Mihic-Probst, D., & Weber, S.A. (2009). The normal width of the linea alba in nulliparous women. Clin Anat. 22:706-711.
  2. Hills, N.F., Graham, R.B., & McLean, L. (2018). Comparison of Trunk Muscle Function Between Women With and Without Diastasis Recti Abdominis at 1 Year Postpartum. Physical Therapy, 98: 891-901.
  3. Mota, P., Pascoal, A., & Bø, K. (2015). Diastasis Recti Abdominis in Pregnancy and Postpartum Period. Risk Factors, Functional Implications and Resolution. Current Women’s Health Reviews. 11.
  4. Lee, D., & Hodges, P.W. (2016). Behavior of the Linea Alba During a Curl-up Task in Diastasis Rectus Abdominis: An Observational Study. Journal of Orthopaedic & Sports Physical Therapy, 46 (7), 580-589.