I thought it's time I post another update to our saga here.
First, funny story. So, I never actually shared that article with the PT. I just talked to her about the flexibility and the things that could have contributed to DD's back problems. We seemed to be on the same page regarding what DD needs to work on, so I left it at that. Couple weeks ago we come in for our usual appointment, and PT says " I found this great website, it's by this guy who is both gymnastics coach and PT, and he posts some great articles on preventing gymnastics injuries. I'll give you the link, and you should share it with the coaches." And of course it's the same website that I've been talking about here.
Now for the actual update. We did another MRI 3 weeks ago, it came back almost all clear. The doctor said "almost" is fine, because it takes some time for the imaging to clear up completely. She approved DD going back to gymnastics. So, now we are working with PT to slowly transition back to gymnastics. Veeerrrryyyyy slooooowwwllllllyyyyy. It's been 3 weeks, and she still isn't allowed to do any back bending, and very little impact. But that's good, we want to make sure this doesn't happen again in 6 months, like last time.
Another thing I wanted to share, in case it would be useful to someone else. One of the members here suggested I look into Myofascial Release (MFR). I did. Found a wonderful therapist not far from us.
She thought the main DD's problem was a constricted Psoas muscle, which made her pelvis tilt forward, creating a curve is her spine, which accounted for the injury. Here is an article that explains it better:
http://thereleaseconnection.com/low-back-pain-and-mfr/
So, MFR therapist has worked with DD for the last 3 months. I think it made a huge difference. DD's pelvis is now back where it should be, and her posture is much better (our sports doctor noticed that too).
So, this is where we are now. Hopefully the combination of PT and MFR will help preventing the injury from re-occurring again.