The class was taught by Katy Bowman, there is a ton of information on her blog here. There is some good stuff if you search pelvic floor or birth or pregnancy. She focuses on attaining the correct length in your pelvic floor so it can generate the most force, rather than just kegels, which over time can cause an over-tight, short, weak pelvic floor. In order for your pelvic floor to be the correct length, your sacrum needs to be in the right position (not collapsed in towards your pubic bone). Habitually tucking your pelvis under when standing or sitting (I have a terrible habit of sitting rolled way back on my sacrum) can cause you to have weak glutes, tight hamstrings and calves, and your sacrum to collapse in. During the one vaginal exam I had in labor, my midwives remarked that the space between my pubic bone and sacrum was narrow. Not what you want to hear when it's time to push your baby out! I did have ds vaginally, without assistance (yay homebirth!). But it took 2 1/2 hours of hard pushing, which I'm pretty sure was the cause of the chronic pain I had post birth. Ds was 6 lbs 9 oz, definitely not big! He was also in a good position for birth.
We learned lots in the class, but I'm focusing on stretching my hamstrings, because they are super tight. So tight, that I can't sit on the floor with my legs in front of me without tucking my pelvis. I'm also focusing on squatting with my shins vertical, and my pelvis untucked. The vertical shins are important, it keeps you using your glutes and hamstrings to hold your weight, which are the muscles I need to strengthen. I can't go very far down with my shins still vertical yet, but I did notice that holding that squat for a minute a few times a day helped relieve the pain I was having.
Other things I've found helpful are switching to the flattest flat shoes I could find. I wore Dansko clogs and sandals throughout my last pregnancy and for about a year afterwards, which have about a 1" to 1-1/2" difference from toe to heel. To adjust for the angle my feet were at I had to tuck my pelvis when standing in those shoes, most people do when their heels are higher than their toes. I noticed a big improvement in my pain after switching to flat shoes. I'm also trying to break the habit of sitting on my sacrum. TMI, but I also realized more recently that holding my breath and pushing when I had to poop was making things worse, so I don't actively push anymore, and I find that I don't ever really have to. Instead, I put my feet up on ds's potty stool and untuck my pelvis and just relax. The pressure of my legs up against my belly helps, and apparently untucking the pelvis unkinks the colon, which helps as well. When I get better at squatting, I'll squat on the stool instead of sitting on the seat. I'm also planning on not pushing during this next birth until it's absolutely involuntary. I didn't really have an urge to push at first with ds, but I was completely dilated, and excited to have him, so I pushed any way. Not this time!
So that's what I've learned! Probably more than you were asking for, lol, but I think it's fascinating!