Pelvic floor and abdominal interaction during and after pregnancy

By focusing on the lower abdominal wall, pregnant and post-natal clients can safely achieve core recruitment, while also protecting and training the pelvic floor, writes women’s health expert Dianne Edmonds.

Core function involves a complex interplay between the deep muscles of the back, the abdominal wall, diaphragm and the pelvic floor. In the deep abdominal wall the lower fibres of transversus abdominus have a role of interacting with the pelvic floor when it contracts, and the external obliques and rectus abdominus have both a movement and supportive role within the core.

There needs to be balanced and coordinated interaction between each of the muscle groups, and, also within the muscle groups themselves. For example, if the external obliques are excessively toned, they may activate more strongly than needed with a low load or control exercise, and for some women, this can inhibit coordinated pelvic floor and transversus function.

Studies have shown that the pelvic floor muscles contract with the lowest fibres of transversus abdominus, but that this pattern can be disrupted in some clients.

Dr Judith Thompson, a physiotherapist from Western Australia, and her colleagues, showed that in women with urinary urgency and pelvic organ prolapse, the coordinated action is disrupted. In 43% of subjects with urgency and prolapse, the pelvic floor descended instead of lifting.

Research by Melbourne physiotherapist Dr Margaret Sherburn, with Professor Kari Bo, a Norwegian physical therapist renowned for her pelvic floor research, and their colleagues, showed that the coordinated action between the pelvic floor and transversus can be disrupted. In a study with a group of students who had demonstrated their ability to perform a correct pelvic floor muscle action, 30% of them depressed their pelvic floor when asked to do just a transversus contraction.

Overactivity or tension in the external obliques or rectus abdominus can also cause excessive intra-abdominal pressure with activation of the core, which in some clients with a weakened pelvic floor can actually cause descent of the pelvic floor instead of a lifting action.

Pregnancy core activation

During pregnancy, the lower abdominal wall is required to support the growing uterus. Postnatal abdominal wall retraining requires specific re-strengthening and shortening, while also protecting and training the pelvic floor.

In teaching pregnancy abdominal activation, the aim is for a deep indrawing action when recruiting the pelvic floor first, followed by activation of the lower and middle fibres of transversus abdominus. If the upper or lateral abdominal wall contracts first then it can push down on the pelvic floor instead of enabling a lifting action of the pelvic floor and drawing in of the lower transversus.

If the upper rectus abdominus is very strong and toned, then its action can become dominant, and inhibit correct patterning when training the lower abdominal wall. Sometimes women who are over-trained in their upper rectus abdominus may splint (rigidly contract) in their upper abdominal region, when attempting to activate their pelvic floor and lower transversus.

For pregnant women the abdominal wall also needs to lengthen, and when there is excessive tension in the upper abdominal wall, rectus abdominus may not allow the ‘give’ that is needed. This may lead to the feeling of tightness underneath the ribs, or a larger separation between the muscles to make room for the growing baby. For some women the ‘gap’ between highly toned upper rectus abdominus muscles is very definite when felt alongside the borders of a tight rectus abdominus muscle.

Upper abdominal wall releasing stretches

Working on releasing the tension in the upper abdominal wall can be done through breathing work, releasing and stretching to enable some more ‘give’ and release, in order to prepare for the growth of the baby inside the uterus and enable lengthening of the abdominal wall.

Prone cobra stretch

For women planning pregnancy or who are in the first trimester and are comfortable in prone, the prone cobra stretch can provide some elongation into the upper rectus abdominus muscles. 

Extension over a Swiss ball

Lengthening over a Swiss ball also provides the client in early pregnancy with a way to stretch the upper abdominal wall.

Precaution: in order to prevent overstretching, ensure clients move into a comfortable stretch; are aware of the level of thoracic mobility range; add in arms for further stretch if comfortable; and drop the hips down to move back off the ball (to prevent overstraining).

Sitting extension stretches

For this movement, the client simply sits and leans back comfortably. Hands can be placed behind the back to increase the stretch.

Child’s pose

The child’s pose can allow control over the amount of stretch and release given to the upper abdominal wall.

Precaution: in order to prevent any pelvic joint pain, ensure clients allow gentle release and stretch as much as is comfortable for them. Time spent in the position and the degree of stretch varies according to the individual and their stage of pregnancy: some prefer longer holds, gently elongating and releasing.


Adding in rotation stretches during training programs and prior to pelvic floor exercises can reduce the degree of overactivation, if this is an issue for a client. Releases and stretches for the external obliques can be included in different positions, including supine (prior to 16 weeks of pregnancy) and side lying rotation stretches, and 4-point kneeling rotation stretches. Seated stretches can also be performed when sitting on a Swiss ball.

Breathing focus

Focusing on breathing easily first – before pelvic floor recruitment – can reduce the amount of overactivity in the upper abdominal wall. Taking 3 to 5 slow breaths before performing a pelvic floor contraction can expand the lower ribcage and assist in reducing the activity of external obliques. Using a breathing focus first enables women to connect to their pelvic floor and the lower abdominal wall instead of contracting the upper abdominal muscles first. It helps them to connect to the more internal feel of these muscles working as their abdominal wall changes and lengthens during pregnancy.

When including core training for women during and after pregnancy, ensuring there is coordinated action between the abdominal wall and the pelvic floor enhances core function.
Focusing on breathing techniques and releasing stretches to the upper rectus and external obliques during training programs can assist in changing the pattern of recruitment in the abdominal wall and protect the pelvic floor from excess pressure during training.


To develop your expertise in training pregnant and post-natal clients, CLICK HERE to find out more about Network’s range of courses, accredited for CECs and CPDs.

Dianne Edmonds is a physiotherapist working in an Obstetric GP clinic, a course creator and Women’s Health Ambassador for Australian Fitness Network and the Director of The Pregnancy Centre. She has worked in women’s health and fitness for 25 years and was integral in the development of the Pelvic Floor First resources.

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