Something I’ve really come to notice during my time with SI joint issues is the effect of my hormonal cycle on my ligaments.
I saw a female pain specialist once who put it very plainly:
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.
Why does this happen?
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 names 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, so our bodies are prepared in the event that we do become pregnant.
And with more relaxin circulating in our bodies, our muscles and especially our ligaments are going to be a little more slack, meaning there is more risk for injury.
This article from BBC News outlines a few studies that have shown women are more likely to experience injuries in the second half of their menstrual cycles, due to higher relaxin concentrations.
I have definitely noticed this going on in my own body. For me, it begins 3-4 days before I get my period, right when I get my other PMS symptoms. All of a sudden, I’ll feel my SI joints start to move around a lot, because my ligaments are not holding them in place as tightly.
There were times when I’d have to promise myself, in those days leading up to and during my period, that I wouldn’t judge my overall progress by the way things were at that moment in time. (I’m sure my plummeting mood didn’t help with my gloomy outlook, either).
I’d really have 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).
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).
I also notice my hormonal fluctuations impacting other joints in my body as well. I particularly notice it in my knees and in the joints of my fingers. (That sounds totally random, but interestingly enough, finger joints were one of the joints that doctors studied, according to that BBC News article).
So, for my female readers, this is something to be aware of.
If you are struggling with chronic pain, 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).
For more, check out this really informative article from Lindsay Matthews at Breaking Muscle on Relaxin: Facts Female Athletes Need to Know.
I also just started using the Clue period tracker app. It seems pretty easy to use so far.