This is a suggestion for anyone who is suffering with SI joint trouble and finding it hard to shake. Someone in a thread here had heard that sitting on a gym ball could help. I can confirm that this completely solved the problem for me when nothing else did. I sit on it all day at work, after 3 weeks intractable symptoms had all but disappeared. I'd gradually gone from olympic distance tri training and half marathon distance running down to nothing at all over 7 months whilst I tried to get rid of it. But I've finally been able to start bike training again without symptoms recurring. Planning to add in a basic running programme next month. I thought I would post in case others would benefit from this experience. Oh and my posture has improved - someone asked me last week if I do ballet!