I've just had a really nasty pain in my side, on the pelvis/pelvic girdle. It feels like it was related to some core supportive muscle. While it's mostly resolved within 72 hours, I'm curious what I probably did to myself.
At the start of this week (Monday), I went back to finish some heavy physical (manual) work I hadn't done for many weeks. Over a 2 day period, it included a considerable amount of reaching into an awkward (hard to access) location, and digging out clay soil/gravel and pushing in replacement clay, at a very awkward angle. The ground is covered by beams about 18 inches apart, and I needed to get about 2 feet below them and dig there. For part of it, I could get down between the beams, but for other parts I needed to reach from above or from awkward angles from adjacent spaces.
The shovel was a small handheld one, so it wasn't that heavy, but the force to push it into the ground, or hammer soil into place, and lift it out at awkward angles, was quite a strain. By that I mean that for part of it I was having to hold the (quite small!) shovel backwards in my hand and dig backwards, for other parts I was resting over a beam on my stomach/pelvis tilted head close to vertical to reach down to where I needed to get.
I was also quite considerably twisted mid torso while doing this, both to reach where I could work, and when moving, or lifting, or dumping the soil out of the hole, and this meant I was twisted while either exerting force or trying to move - so the poor positioning and twisting and reaching were dynamic while moving loads and exerting force, not just static in between them.
I also had a small amount of heavy lifting, which I did properly (ie not putting spine and back at risk).
There wasn't much like of this, but it required muscles working in difficult/unusual directions and I knew it would leave me aching for a day afterwards.
The day after finishing (Wednesday?), I got a pain I've never had before, in a location I've never had it before either. It felt like it originated at the top of my pelvic girdle, about halfway between my left side and spine in my back. (I'm right handed if it matters)
Because spinal pain can be nerve related or mislocated, there's a chance the issue was elsewhere, but I don't think it was. It didn't feel like it was related to muscles of the spine as my back itself didn't hurt.
The sensation was stabbing and eye-watering. It was quite similar to how a sharp cramp in the calf feels. It stayed local in the pelvic area, so I didn't feel pain in my spine or close to my spine, or in other places on my back or hips or leg. It seemed to be very closely related to core supporting muscles, because when I was sitting on a chair, and my body automatically used the front and back torso muscles to maintain an upright sitting position, the act of that muscle group automatically tensioning to pull my body a bit more backwards was when it really hurt most.
Over about 48 hours, more than a few times, it took time and effort to get up from lying in/on the bed, to try and find a way to get vertical that wouldn't cause that pain. But if I walked slowly and tried to keep my torso vertical (and avoid that automatic self-correcting movement), it mostly wasn't a problem walking around or working. I found myself holding my back slightly tilted forward at the pelvis in a way that made me think of the lumbar posture associated with spondylosis, but I knew that was just accommodating the pain and wouldn't last more than a few days. To get out of bed, I moved my legs across and off the bed, to help me tilt and raise my body from a prone position, which made it easier.
There was also a slight pain from the matching place at the front of my pelvis, but that felt more like a "reflection" of some kind of the original pain, if that makes sense - not an actual or second injury site. If I had to guess, I suspect that the opposing muscle group may have been under unusual load or strain as a result, and suffered somewhat?
I only very rarely use painkillers but this one was severe enough that I dug up some old co-dydramol and an ibuprofen for any inflammation, to handle it, without hesitation, which helped. I did the same the second day as well.
After 2 nights (about 48/72 hours after the pain started) (Friday) it began to diminish to feel more like a bad battering or bruise, so it's pretty much ignorable now.