Thanks all for your help!

I'm beginning to become convinced it's an SI joint issue.

Standing on one leg:
- pain on the left side (injured side), but no more intense than when standing on two

Lying on back leg lifts
- no problem either leg

Twists are excrutiating
So are forward bends
Backbends are fine (as long as i don't twist)

I have visible swelling/inflamation (way over to the left on top of pelvis). Pain sometimes radiates into my hip joint.

Any special treatment tips would be appreciated. I've read that scar tissue needs to form to stablize the joint. I've been practicing really heavy stretches for 5 years so it's quite possible that my SI joint is unstable.

Thanks again,
Lucas