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Postpartum Exercise and Diastasis Recti Abdominis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04122924
Recruitment Status : Recruiting
First Posted : October 10, 2019
Last Update Posted : April 7, 2022
The Norwegian Women´s Public Health Association
Information provided by (Responsible Party):
Kari Bø, Norwegian School of Sport Sciences

Brief Summary:

Prevalence rates of diastasis recti abdominis (DRA) among postpartum women vary between 30% - 68%. It has been postulated that DRA, in addition to being a cosmetic concern for many women, may reduce low- back and pelvic stability causing low back- and pelvic girdle pain and be related to pelvic floor dysfunctions such as urinary incontinence, anal incontinence and pelvic organ prolapse. Given the limited research data, there is currently no consensus on which abdominal exercises to recommend to narrow the diastasis.

The purpose of this assessor blinded parallel group randomized controlled trial (RCT) is to evaluate the effect of abdominal muscle training on inter-recti distance (IRD) and prevalence of DRA.

Condition or disease Intervention/treatment Phase
Diastasis Recti Abdominis Diastasis Recti Other: Abdominal muscle training Not Applicable

Detailed Description:


DRA is defined as an impairment with midline separation of the two rectus abdominis muscles along the linea alba. The condition affects a significant number of women during the antenatal- and postnatal period. Today there is a strong focus on the pregnant woman's appearance, especially through social media. Webpages and apps recommend how women should stay thin and get back into shape with "a flat tummy" at an early stage of the postpartum period. There are easily available advices on how to get rid of what is named "the mum's belly" (,,,, A systematic review of the scientific literature has found none or very weak evidence behind any of these advices. DRA is diagnosed by measuring the distance between the median borders of the two rectus abdominis; IRD, and ultrasound has been found to have the best intra- and inter-tester reliability with Intraclass Correlation Coefficient (ICC) > 0.9.

In a systematic review by Benjamin et al. (2014), 8 studies in treatment of DRA using abdominal exercises were found: four case studies, two retrospective observational studies, one quasi-experimental post-test study and one small RCT of a brief training intervention. A new search on Pubmed of July 2019 found six additional RCTs using abdominal exercises in treatment of DRA. The studies differ in methodological and interventional quality and results differ between studies. Given the limited research data, use of different outcome measures and cut-off point for diastasis in published studies, there is currently no consensus on which abdominal exercises to recommend to narrow the diastasis.


The aim of this study is to assess the effect of abdominal muscle training on IRD and prevalence of DRA in postpartum primi- and multiparous women.


Before starting this RCT, an experimental cross-sectional study investigating the acute effect of different abdominal- and pelvic floor exercises on IRD in women with DRA will be conducted. Based on findings from the experimental cross-sectional study, we will choose exercises that narrow the IRD for the RCT's exercise program.

Women will respond to an electronic questionnaire sent by email before they meet for the clinical assessments, before and after the intervention period. Women diagnosed with DRA giving informed consent are assessed at baseline with 2D ultrasound measurements of IRD, abdominal muscle strength tests and the Oswestry Low Back Disability Index (ODI), Pelvic Girdle Questionnaire (PGQ) and (Pelvic Floor Disability Index) PFDI-20. After baseline testing the participants are randomly allocated to either an exercise or control group. Randomization will be computer-generated, in blocks of 4 with concealed allocation. Randomization will be provided by a person not involved in assessments of outcome. The outcome assessor will be blinded for group allocation. After the 3 month training period, both the exercise and control group will be reassessed with 2D ultrasound, abdominal muscle strength and endurance tests and the ODI, PGQ and PFDI-20.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 70 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: An assessor blinded parallel group RCT
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of Abdominal Muscle Training on Inter-recti Distance and Prevalence of Diastasis Recti Abdominis in Postpartum Primi- and Multiparous Women: A Randomized Controlled Trial
Actual Study Start Date : January 9, 2020
Estimated Primary Completion Date : February 20, 2023
Estimated Study Completion Date : April 2023

Arm Intervention/treatment
Experimental: Intervention Group
A three months home-based abdominal muscle training program.
Other: Abdominal muscle training
The intervention starts 6-12 months postpartum and will last for three months with weekly follow-up through an exercise app. Before commencing the home-based program, women in the intervention group will have an individual session in how to perform the program with a physiotherapist. The intervention consists of a 10 min 5 days a week exercise program, including the following exercises; headlift, crunch and twisted crunch. General principles for strength training are followed: 3 sets of 8-12 contractions close to maximum. The participants will be provided with a smartphone app (Athlete Monitoring) to be reminded to exercise and to register adherence.

No Intervention: Control Group
The control group will have no intervention, and will be asked not to attend any specific supervised abdominal muscle training program during the 3 months intervention period.

Primary Outcome Measures :
  1. Change in IRD assessed by 2D ultrasonography [ Time Frame: Change from baseline IRD at 3 months ]
    A portable 2D ultrasound (GE Healthcare -Logiq e R7) will be used to assess IRD inn mm at 2 cm above and 2 cm below (P. G. Mota et al., 2015a) the umbilicus during rest and crunch.

Secondary Outcome Measures :
  1. Change in abdominal endurance [ Time Frame: Change from baseline abdominal endurance at 3 months ]
    Abdominal endurance will be assessed as number of repetitions of one standardized abdominal crunch to exhaustion (ACSM, 2006).

  2. Change in abdominal strength [ Time Frame: Change from baseline abdominal strength at 3 months ]
    Maximal abdominal strength will be measured in a trunk dynamometer (HUMAC NORM).

  3. Change in cross-sectional area of m. rectus abdominis [ Time Frame: Change from baseline cross-sectional area at 3 months ]
    Cross-sectional area of m. rectus abdominis will be measured by 2D ultrasonography, above and below the umbilicus.

  4. Change in symptoms of low back pain [ Time Frame: Change from baseline symptoms of low back pain at 3 months ]
    The electronic questionnaires include the following instrument: Oswestry Low Back Disability Index (ODI).

  5. Change in symptoms of pelvic girdle pain [ Time Frame: Change from baseline symptoms of pelvic girdle pain at 3 months ]
    The electronic questionnaire include the following instrument: Pelvic Girdle Questionnaire (PGQ).

  6. Change in symptoms of pelvic floor dysfunctions [ Time Frame: Change from baseline symptoms of pelvic floor dysfunctions at 3 months ]
    The electronic questionnaire include the following instrument: Pelvic Floor Disability Index (PFDI-20).

  7. Global rating of change (GRC) [ Time Frame: Post-test after a 3-months intervention period ]
    Perceived change of the condition will be assessed by a numerical 11-point scale. A 11-point scale with response choices ranging from "completely recovered" to "very much worse".

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Primi- and multiparous women 6-12 months postpartum
  • Understand instructions given in Norwegian language
  • Willing/available to participate in a 3 months intervention period

Exclusion Criteria:

  • Pregnant women
  • Women < 6 months or > 12 months postpartum
  • Women with children with illnesses and mothers with neurological, systemic musculoskeletal diseases or psychiatric diagnoses will be excluded from participation
  • Women with adherence < 70 % of the home-based program will be excluded for the per protocol analyzes
  • Women with specific need for pelvic floor muscle training during the 3 months intervention period will be excluded

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT04122924

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Contact: Kari Bø, PhD +4723262008
Contact: Sandra Gluppe, MSc +4797523133

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Norwegian School of Sport Sciences, Department of Sports Medicine Recruiting
Oslo, Norway, 0863
Principal Investigator: Kari Bø, Phd         
Sub-Investigator: Sandra Gluppe, Msc         
Sponsors and Collaborators
Norwegian School of Sport Sciences
The Norwegian Women´s Public Health Association
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Study Chair: Kari Bø, PhD Norwegian School of Sport Sciences
Rett, M. T., Braga, M., Bernardes, N., & Andrade, S. (2009). Prevalence of diastasis of the rectus abdominis muscles immediately postpartum: comparison between primiparae and multiparae. Revista Brasileira De Fisioterapia, 13(4), 275-280. doi:10.1590/s1413-35552009005000037
Venes, D., & Taber, C. (2013). Taber's cyclopedic medical dictionary (22. ed.). Philadelphia: FA Davis Co
Mesquita, L. A., Machado, A. V., & Andrade, A. V. (1999). Physiotherapy for reduction of diastasis of the recti adbominis muscles in the postpartum period. Rev Brasil Ginecol Obstet 21, 267-272.
Tuttle, L. J., Fasching, J., Keller, A., Patel, M., Saville, C., Schlaff, R., . . . Gombatto, S. P. (2018). Noninvasive Treatment of Postpartum Diastasis Recti Abdominis: A Pilot Study. Journal of Women's Health Physical Therapy, 42(2), 65-75. doi:10.1097/jwh.0000000000000101
Walton, L. M., Costa, A., LaVanture, D., McIlrath, S., & Stebbins, B. (2016). The effects of a 6 week dynamic core stability plank exercise program compared to a traditional supine core stability strengthening program on diastasis recti abdominis closure, pain, oswestry disability index (ODI) and pelvic floor disability index scores (PFDI). Physical Therapy and Rehabilitation, 3(1), 3. doi:10.7243/2055-2386-3-3
Bø, K., et al. (1990). Pelvic floor muscle exercise for the treatment of female stress urinary incontinence: III. Effects of two different degrees of pelvic floor muscle exercises. Neurourol Urodyn 9(5): 489-502.

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Responsible Party: Kari Bø, Prof, PhD, PT, Exercise scientist, Norwegian School of Sport Sciences Identifier: NCT04122924    
Other Study ID Numbers: SLG89
First Posted: October 10, 2019    Key Record Dates
Last Update Posted: April 7, 2022
Last Verified: April 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Kari Bø, Norwegian School of Sport Sciences:
Abdominal Muscle Training
Additional relevant MeSH terms:
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Diastasis, Muscle
Joint Dislocations
Joint Diseases
Musculoskeletal Diseases
Wounds and Injuries