Thank you for asking. After years of doing asanas I've come to the place of wanting to know the finer details of proper alignment, which you do so nicely. We want to be able to keep doing asanas as we age without hurting ourselves in the process. So focusing on the sacrum/pelvic girdle area seems to be important as well as all the other major joints. I'd be interested in a talk about yoga as we get older. (Patricia Sullivan's videos do this.) I just looked at your response to Janet and it sounds like you are planning some amazing classes.