A couple of years ago, Spinal Research got an exciting funding application that we were all too keen to get behind. At the time, debate was raging around the use of chiropractic adjustments during pregnancy and infancy. Dr. Heidi Haavik and her co-investigators, Dr. Jenny Kruger and Professor Bernadette Murphy were keen to investigate whether adjusting vertebral subluxations would alter pelvic floor muscle function.

The results are in and the research report has been approved for publication, but as these things take time we thought you’d like the scoop. This is big news for women and chiropractors alike!

  • The study demonstrated that adjusting the pregnant women appears to relax the pelvic floor muscles at rest [1]. As there were no changes seen when they adjusted the non-pregnant comparison group, this finding in the pregnant women appears to be an effect unique to pregnancy.
  • This relaxation of the pelvic floor muscles seen after they were adjusted may mean that chiropractic care could be of benefit to pregnant women, as it may help them have a natural vaginal delivery [1].
  • A secondary interesting finding of this study was that the non-pregnant chiropractic students in the comparison study were able to contract their pelvic floor muscles to a degree previously seen only in elite athletes. We don’t yet know exactly why, but a possible explanation for this is that they were chiropractic students who were regularly getting checked and adjusted and this may have been why they had such amazing control over their pelvic floor muscles. It’s also possible this would have a preventative effect against future pelvic floor dysfunction such as stress urinary incontinence! But the researchers say this needs to be followed up with future studies

Why the Pelvic Floor Study Matters

wo00119_im01396_mcdc7_femalekegelexercisesthu_jpg.pngThe pelvic floor muscles (the Levator Ani muscle complex) are known to have active roles in pregnancy and childbirth, as well as in spinal stabilisation. When the pelvic floor muscles are damaged or stressed over time, health issues like incontinence and vaginal prolapses can crop up [1]. We know these are problems with massive emotional, physical, social and financial costs across the world and a significant cause of stress for these women.

For a woman in labour, the ability to relax pelvic floor muscles (as well as contract them) to allow the baby to move through the birth canal is incredibly important, especially as the baby crowns. If the woman can’t relax these muscles as the baby moves through, she will tire more quickly and may require more interventions to assist the birthing process [2]. Muscles that cannot relax could also interfere with a birth progressing without interference. In an ideal situation, strong pelvic floor muscles with an ability to relax would better prepare a mother for a natural, vaginal birth.

The primary findings of this study are incredibly encouraging, especially given the fact that quantitatively assessing the effect of spinal adjustment on pelvic floor muscle function has not previously been done [1]! The study came about when Dr. Jenny Kruger, a midwife who completed her PhD on imaging the pelvic floor, approached Haavik. The two worked with Dr. Bernadette Murphy, who had supervised both of their PhD’s. Kruger and Haavik decided to combine their interest areas to study the PFM’s after spinal adjustments.

The study saw participants undergo ultrasounds, and perform three different manoeuvres – squeezing as hard as they could, bearing down (that pushing which opens up the Hiatus hole in the pelvic floor) and at rest. They studied the women in the control group and the active group, and looked at them pre and post adjustment.

“We were expecting to see changes on the squeezes and the pushes and all of that, but we saw nothing. But what was really interesting is that the actual (hiatus) hole itself got larger at rest. What it suggests is that those muscles that form the Pelvic Floor rim that holds all our internal organs and that move to give birth to the baby, must have relaxed,” said Heidi Haavik in a recent interview with Spinal Research.

“That alone is extremely exciting…Opening up those muscles is so important to be able to give birth.”

A second interesting finding from the study

Given the hormonal and physiological changes involved in pregnancy, the researchers added a comparison group to the mix. This group was made up of non-pregnant chiropractic students, and it is also where this study got very interesting.

“Again there weren’t any major pre and post adjustment changes, but our students were capable of contracting their Pelvic Floor muscles to a degree that has only previously been seen in top, elite athletes. I was quite blown away.  Jenny was quite blown away because this is very, very unusual,” said Haavik.

This secondary finding is an incidental but interesting one. It raises enough questions to demand a study of its own as we don’t yet know what it means. It could be that because they are chiropractic students who are being adjusted regularly, their sensory-motor control is greater. But far more work needs to be done before we accurately interpret the results.

What could this study mean?

Again, it’s early days in terms of understanding the full impact of this study’s findings. We do know that adjusting women in pregnancy gives them a greater ability to relax the pelvic floor. We also know that something very unusual occurs in chiropractic students who are being adjusted regularly.


  • For pregnant women, this has the potential to give them a greater degree of control over the pelvic floor muscles, which in turn may make vaginal childbirth easier. At this point, we can only speculate on what the impacts could be in terms of reduced need for medical interventions, or increased well-being of mother and child. But it does show us that chiropractic may be of benefit to pregnant women.
  • For non-pregnant women who get checked and adjusted regularly, we may potentially be looking at a completely different set of benefits. It is possible that this improves the condition of the pelvic floor muscles, enables greater sensory-motor control, and potentially decreases the risk of future stress urinary incontinence, faecal incontinence and vaginal prolapse. This is an extremely exciting possibility!

Haavik concedes that these are big ‘ifs.’ Once again, more research is required but the flow on effects could be far reaching.

“Why I’m even bothering with this line of research is because 1) we could potentially increase the rate of healthy, uncomplicated vaginal births and deliveries. As soon as you add interventions, their problems just skyrocket. Increasing the chances for women to have a natural, vaginal delivery is where I’m headed with this work. 2) Also preventing pelvic floor muscle problems for women, preventing stress urinary incontinence for example. There’s actually very little research on female pelvic floor problems. It’s surprising! If we can have uncomplicated, natural vaginal delivery without drugs and intervention, the baby is better off and the woman is better off. I’m quite convinced that chiropractic care can actually help with this, but this needs to be systematically explored with properly conducted scientific studies.”

What’s next for this area of study?

“We’ve started a second study, which again Spinal Research has funded, and we have reached the point where we are getting preliminary results,” says Haavik. Again, Dr. Jenny Kruger approached Dr. Haavik with a topic to collaborate on. This time it focused on stress urinary incontinence (SUI).

At present, whether or not a woman will get SUI post-childbirth is a bit of a lottery. Some get it, some don’t.

What is supposed to happen is that when we contract those muscles, the left and right sides are supposed to contract at the same time. The superficial muscles are supposed to contract first, and then the deeper muscles follow just 21 milliseconds later. But in women with SUI, this timing is all out of whack.

“It could be that when we are subluxated, that the timing of the muscle contractions become stuffed up,” says Haavik. The researchers have been screening women with timing issues and adjusting them. “We’ve screened hundreds of women and adjusted a lot of them too. We are looking at several measures all in one go.”

We will save the results of this study for another blog post, but it’s another study chiropractors and their female patients are going to want to know about!

Download a Poster

Keen to share these amazing results with the people under your care in your practice? Download a Poster to use in practice.



[1] Pelvic floor functional changes with spinal manipulation in pregnant and non-pregnant women: A pilot study. JMPT 2016. In Press.

[2] http://www.babycenter.com.au/a536339/your-pelvic-floor-in-pregnancy

[3] Heidi Haavik, interview with Spinal Research.