SPD isn't really something you can stop from happening. Sometimes, you can help it using physical therapy. I vacuum, lift heavy, stand and walk a LOT, etc., as well. I'm prone to it and have had it with every single pregnancy. I am more careful, as I once popped my pelvis out at 12 weeks along and had to deal with that pain for the rest of the pregnancy, and as I have more pregnancies, my SPD lasts longer postpartum. Last time, my baby was 2 months old before my pelvis stopped popping on a daily basis. So, I'll tell you what I personally do in order to keep my SPD from being any worse than it needs to be...
I try to take a lot of breaks if I'm going to be walking a lot. My kids and I like to go on 3-mile walks, and we're not about to stop going for our walks. If we're outside walking, we'll sit on the sidewalk for a minute and look at the birds or something. If we're in a store, I'll lean on a shopping cart for a few minutes while my kids enjoy the toy aisle. If we're at the beach, we'll start digging in the sand!
I put on my pants and underwear in a seated position. This seems silly, but I have popped my pelvis really badly by standing to put my underwear and pants on, and the pain lasted for months. It's not worth it. Just sit down.
I keep my knees together when I roll over in bed. It's HARD to roll over when you have SPD. Once I'm in the last couple of months of pregnancy, I have to ask my OH to help me roll over because I'll get stuck on my back. lol... I also have to ask for help getting out of bed in the last couple of weeks of pregnancy, sooo OH gets used to it soon enough. Or OH tells me to sleep on the air mattress where I can roll easily. Oh, same rule applies for getting out of the tub and getting in/out of the car. Watch that you don't pop that pelvis, or the pain could last months.
I don't lift my legs up high. I once lifted my foot up so my OH could tie my shoe for me. POP! Oh, that was awful.
Don't sit for too long! I have a timer that goes off if I sit for 20 minutes so I know to get up and move around for a while. Use it or lose it!
I got a lighter vacuum. Sweeping pulls my hips out of alignment, especially since I was born with hip dysplasia and pregnancy (relaxin) aggravates it and puts me in a lot of pain. I have a Shark Rocket, which I can use without twisting or anything, and it's light enough that my kids can vacuum for me.
If you have an extra couple bucks to put into it, I'd highly recommend... Especially for those of us who have multiple kids, and especially if you have furry pets like I do. I vacuum my kitchen and dining rooms after every meal, and I vacuum the other high traffic areas in my house daily. I haven't aggravated any symptoms with my new vacuum, but I had a regular upright and a canister vacuum which did make me miserable.
Here is a list of yoga poses/stretching I personally find VERY relieving... They let me stretch the painful areas, relieve pain and strengthen the muscles supporting those joints.
https://birthbliss.wordpress.com/20...p-ease-pain-from-pubic-symphysis-dysfunction/