Something my female readers ask me pretty about often is whether our hormones can play a role in SI joint dysfunction.
The answer to this question is definitely yes — although it’s something you may not notice as much, once you become stronger.
Basically, one of the hormones a woman’s body releases in the days leading up to her period is a hormone called relaxin.
As the name suggests, relaxin acts as a chemical messenger that tells our muscles and ligaments to relax. Its main effect during childbirth is to cause the joints of the pelvis to become looser, meaning there is more room for the baby to pass through.
However, relaxin is also released during our menstrual cycle, beginning around day 14, in preparation in the event we do become pregnant, meaning the concentration is higher in our bodies during the second half of our cycle.
I saw a female physiatrist once who explained it so clearly:
“I have extremely healthy women come into my office– women who are runners, women who are training for marathons– and sometimes it seems like, during their period, all they have to do is bend over and tie their shoe, and they can throw their back out.”
This is the effect of relaxin– it loosens our ligaments up, to the extent where we cannot always count on them to hold things in place those few days of the month, where normally they would.
I have definitely noticed this going on in my own body. For me, during the worst of my saga, it would begin 3-4 days before I get my period, right when I ‘d get my other PMS symptoms. All of a sudden, I would feel my SI ioints start to move around a lot.
Back when I was doing worse, and my joints were more prone to locking up, they would start locking up much more easily.
It got to the point where I sometimes had to swear to myself, in those days leading up to and during my period, that I wouldn’t be tempted to judge my overall progress by the way things were at that moment in time, and not to lose hope. (I’m sure my plummeting mood didn’t help with my gloomy outlook, either).
I really had to talk myself through, and say, I know things really seem that bad right now, but your joints ARE doing better. Just wait a few days and see.
And then, sure thing, once my period had passed, things would go back to normal (or at least, back to baseline anyway).
2017: Since my SI joints are doing better now, I don’t notice quite the same extreme fluctuations in my level of function. I have more muscle strength to hold things in place, and my ligaments have had more of chance to heal after my original injury.
However, every month, I can still feel things become a little looser, and my SI joints seem to have a wider range of motion (and not in a good way).
Update, 2022 Version:
Since I wrote this original post in 2017, so much has changed. I no longer really notice the impact of my monthly cycle on my SI joints, because I have enough muscle strength to cover up whatever is going on with my ligaments.
So, although my body is still releasing relaxin each month, I can actually still do things like exercise and hiking– which I used to have to avoid– the same way I can at any other time in my cycle.
So to all the ladies out there, if you’re dealing with SI joint dysfunction (or any chronic musculoskeletal issue) this is definitely something to be aware of.
It might be worthwhile for you to track how your menstrual cycle impacts your pain. I honestly was totally unaware of the connection, until that doctor suggested I start paying attention.
Once I knew, it did make things a little easier. I learned not to freak out if things felt worse during a certain time of month, and instead knew to wait, and that it would probably pass (which it did every time).
Becoming aware of this cycle is what taught me when to push myself, and when to rest– knowing that a strategic pause at the right time would actually still play a role in my recovery.
For more info, here are some links to check out:
This really informative article from the BBC News: Menstrual cycle injury risk link
Scientific iterature review: The effect of relaxin on the musculoskeletal system
The Clue app helps you keep track of your hormonal fluctuations each month. I checked it out and it seems pretty easy to use so far!