It’s possible for several days or even weeks to pass from the time you sprain the ligaments of your SI joint to the time you develop symptoms, or feel the joint start to move.
In 2011, I first sprained my SI joint ligaments by sitting down way too hard in what I thought was a soft, cushioned wheelchair (I was at the hospital to get an x-ray for my knee). It turned out that there was, in fact, a metal bar located directly underneath the flimsy “cushion” and I basically whacked my left butt cheek (aka my left SI joint) really hard on that bar.
At the time, I remember feeling as though something had to have been injured… that was way too much force for my body to absorb and have nothing be wrong.
Yet I was able to stand up, and walk around, and be okay.
It wasn’t for another two or three weeks, if I remember correctly, that my SI joint actually moved out of place and locked up for the first time.
The same happened with this recent fall. Although I had some pain and felt extra mobility, it took a whole ten days before I felt the joint noticeably move and lock, in a way that exactly recreated the pain of my fall.
Because the pain I felt from the fall was in a new place (much lower down within the joint), and because I felt the joint lock up in this same place (much lower down) the most likely explanation is that I sprained the ligaments in that area, which caused the joint to become unstable at that point.
(The SI joint has like a bajillion ligaments, and yes, some ligaments can be sprained while others are not, given what happens and the location/direction of the impact).
We know that ligaments can take weeks if not months to heal, and that ligaments which have been stretched out (which happens as part of a sprain) never really fully recover their original, shorter length. A joint which has been sprained once will always be a little bit less stable and prone to injury (although there are different techniques to help it heal as much as possible).
So, what I’m taking away from this, for my future treating SI joint injuries as a physical therapist, is that the fallout from an SI joint ligament sprain might not be immediately apparent.
Sometimes, I expect, you can have a patient with an SI joint injury who does not know if or when they first injured their SI joint ligaments, because so much time might have passed they might not have made the connection between the two events.
For me, it was approximately 3 weeks the first time, and ten days the second time.
How is this possible?
Well, it seems as though it takes some time for the ramifications of having one or more of the ligaments compromised to occur. After all, there are other things holding the joint together: muscles, other ligaments, and the fact that the surfaces of the ilium and sacrum are meant to fit together, so they don’t come apart super easily.
But over days or weeks, slowly things can change. Having one ligament sprained (which means it can be stretched out and inflamed) can irritate other ligaments and spread irritation.
It can also mean that other ligaments as well as muscles have to do more work than they are intended to, and over time this can have a detrimental effect on them as well.
Additionally, studies have shown that having back pain can actually inhibit the action of some of the back muscles, as well as the core muscles. This is counter-productive because we need those muscles to be firing in order to help keep the back stable! If these stabilizing muscles are inhibited, then we are subjecting the joint to even more stress.
For all these reasons combined, it does appear that it can take a little while for a ligament sprain to translate into real symptoms that we notice, and joint hypermobility (or the joint getting stuck).
I know this is a lot of information, and it can be confusing (even for me– that’s why I have to write my thoughts down on this blog!).
If you want to know more about the effects of ligament sprains on the SI joint, here is a really clear and informative video from an SI joint surgeon on how ligament sprains and inflammation can cause a joint to become less stable:
(Also here are some notes that I took on it).
So, don’t worry about me; I am not scared. At the risk of jinxing myself, I expect this “injury” to just be a temporary setback, because of all the things I have learned about the SI joint and how to take care of my own particular body.
At this point I’m viewing this as a learning experience, and I’m actually curious to see what happens next.
SI joint ligament picture above courtesy of Wikipedia/Gray’s Anatomy