HI Bensims

I have been struggling with the same problem for 18 months now. have had to go through rigorous examination to rule out (and was told by all practitioners involved that their diagnosis was the cause) FAI, MS, lumbar spine issues, reactive arthritis and psychological causes. from the beginning this pelvic imbalance (and i agree with the above thread that its more a muscle imbalance resulting in hypertonic painful muscles and ligaments than an "Wikipedia reference-linkSIJ" issue) was my suspicion but it has taken so long to confirm and only now am i really getting adequate treatement and am improving slowly. what you need to take into consideration is that once you have had pain for more than 3 months, you body is in a "chronic pain" state. your wiring has been interupted and muscle function is hindered.
in the past i had done all the glut med strengthening, core stabilisation, pilates (i am a physio and pilates instructor so i would hope i knew what i was doing) and all the METS were performed on me etc....
the only thing to date which i s actually helping me is a combination of dry needling right down the spine to assist in releasing my extremely hypertonic erector spinae/multifidus and my opposite iliopsoas and adductor complex. its intense and painful at the time but has given me massive relief. i have only had two sessions (going for my third today) and have increased my quality of life from about a 3 to a 6. still not running and probably will never play soccer again (all the soccer injuries which i think have been a huge contribution to the problem). i also see an osteopath once a week on my doctors recommendation and she is doing her thing. before i had the needles it wasnt of much benefit but i think the combination of needles to re-wire my system and osteopathy and pilates is getting my strength and proprioception back gradually (i previously had no idea i was standing completely skew and could not lie in a straight line).
now the thing with needling is you have to find an expert. they are few and far between. many will just tap the needle in and leave it there. you need someone who can feel for the hypertonic muscle bands and dig into them til you get a twitch. its an awesome feeling!
as with all pain issues, address the emotional component. pain can cause us to feel useless and miserable and its worth talking it through with someone and see if there are any other contributing emotional factors. i know it sounds very text-booky and pathetic but its worth it.
last piece of advice i can give you is rest from activity until you are feeling at least 90% better. swimming is great for the lumbar spine but if your muscles are not working correctly you may still be over activating (especially adductors if doing breast stroke for example). running is a definite no no. as annoying as it is just take it easy!!
please keep us updated on your progress and hopefully we will both be up and running in good time.
take it easy