Diaphragm and Breathing Muscle Characteristics in Women With and Without Diastasis Recti Abdominis After Childbirth

NCT07389993 | Recruiting DMC

• 1 other identifier: DRA-DIAPHRAGM-PILOT
• Study Type: observational
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

Diastasis Recti Abdominis (DRA) is a common condition experienced postpartum, in which the abdominal muscles separate along the midline of the abdomen due to stretching and thinning of the linea alba. It's a common condition, affecting 66-100% of women post-birth and may be associated with changes in abdominal support, posture, breathing, and trunk function. Although DRA primarily affects the muscles of the abdominal wall, it is speculated that other muscles controlling and stabilizing the trunk, such as the pelvic floor muscles or the diaphragm, might be affected as well. Currently, several studies have investigated the possible negative effects of DRA on pelvic floor function. However, little is known about how it may be related to diaphragm function and accessory breathing muscles. The purpose of this observational study is to compare diaphragm characteristics and function, and accessory breathing muscle strength in women who have given birth, with and without DRA. To make this possible, adult parous women from the broader Achaia region are assessed and allocated into two predefined groups based on the presence or absence of DRA. Participants undergo a single assessment session including rehabilitative ultrasound imaging (RUSI) of the diaphragm and standardized tests of inspiratory muscle strength. Additional demographic and clinical information related to pregnancy and physical activity is also recorded. The main hypothesis of this study is that women with DRA demonstrate altered diaphragm function, as well as reduced inspiratory muscle strength, compared to women without DRA. The study aims to improve understanding of the possible relationship between DRA and breathing function after childbirth and to support future research and rehabilitation approaches for women with the condition.

Conditions

Diastasis Recti Abdominis (DRA)

Keywords

diastasis recti; diaphragm; RUSI; inspiratory muscle strength

Outcome Measures

Primary Outcomes (3)

• Inspiratory diaphragm thickness

  Diaphragm thickness measured via ultrasound in cm at the end of a full inspiration at a standardized anatomical location.

  Baseline

• Expiratory diaphragm thickness

  Diaphragm thickness measured via ultrasound in cm at the end of a full expiration at a standardized anatomical location.

  Baseline

• Diaphragm excursion

  Diaphragm excursion measured via ultrasound in cm during quiet respiration at 60% of inspiratory capacity (IC).

  Baseline

Secondary Outcomes (3)

• Maximal Inspiratory Pressure (MIP)

  Baseline

• S-Index

  Baseline

• Peak Inspiratory Flow (PIF)

  Baseline

Study Arms (2)

Women with diastasis recti abdominis

Parous women diagnosed with diastasis recti abdominis using a standardised ultrasonographic assessment to measure the inter-recti distance (IRD).

Diagnostic Test: Ultrasonographic assessment of the diaphragm; Diagnostic Test: Inspiratory muscle testing

Women without diastasis recti abdominis

Parous women without diastasis recti abdominis, as confirmed by standardized ultrasonographic assessment of inter-recti distance (IRD).

Diagnostic Test: Ultrasonographic assessment of the diaphragm; Diagnostic Test: Inspiratory muscle testing

Interventions

Ultrasonographic assessment of the diaphragm DIAGNOSTIC_TEST

Rehabilitative ultrasound imaging (RUSI) to assess diaphragm thickness and excursion under specific respiratory maneuvers.

Women with diastasis recti abdominis; Women without diastasis recti abdominis

Inspiratory muscle testing DIAGNOSTIC_TEST

A standardized inspiratory muscle strength testing procedure using a POWERbreathe KH2 device to assess maximal inspiratory pressure (MIP), S-Index and peak inspiratory flow (PIF).

Women with diastasis recti abdominis; Women without diastasis recti abdominis

Eligibility Criteria

• Age: 18 Years - 50 Years
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Parous adult women from the local community (broader Achaia region) recruited through invitations and referrals and assessed in a clinical research setting.

You may qualify if:

• Female sex
• Aged 18 to 50 years
• Parous women (at least one previous childbirth)
• At least 6 months postpartum at the time of assessment (and within 5 years postpartum)
• Ability to understand and communicate in Greek
• Willingness to participate and provide informed consent

You may not qualify if:

• Current pregnancy
• Delivery within the previous 6 months
• History of severe chronic respiratory disease (e.g., chronic obstructive pulmonary disease, chronic bronchitis, pulmonary emphysema, pulmonary fibrosis)
• Presence of connective tissue disorders
• Presence of neurological disorders
• Severe musculoskeletal conditions that could affect trunk or respiratory function or limit participation in testing procedures (severe low back pain, sciatica etc.)
• Previous abdominal surgery, with the exception of cesarean section

Sponsors & Collaborators

• University of Patras: lead

Study Sites (1)

Laboratory of Clinical Rehabilitation and Research (CPRlab), University of Patras

Pátrai, Achaia, 26504, Greece

RECRUITING

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Study Officials

• Evdokia Billis, PhD

  University of Patras

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Anastasia Skoura, PhD

CONTACT

00306947784948; a.skoura@upatras.gr

Evdokia Billis, PhD

CONTACT

00302610962406; billis@upatras.gr

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: January 28, 2026
• First Posted: February 5, 2026
• Study Start: May 19, 2025
• Primary Completion: April 3, 2026
• Study Completion (Estimated): May 13, 2026
• Last Updated: April 13, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

GR (1)