Sacroiliac Joints need to be cared for carefully, so in this Sync be mindful to move into each movement with care. There are movements that can strain on the sacroiliac joints, especially seated forward bends, twists, and wide-legged poses. The movements in this Sync can work to realign and stabilse the sacroiliac area. It most important to move the sacrum and the two ilium bones as a unit while keeping the pubic bones together. If any movement at all feels painful, or even neutral, it could be that you do not quite have the correct actions and it is not helpful and may even be harmful to continue. So stop immediately and move to the next movement Before practicing,especially if injured see a qualified teacher or a qualified health professional, such as a chiropractor, osteopath or physical therapist, or a caregiver who has a track record of helping with your specific problem. More information here http://www.yogajournal.com/for_teachers/1028