These stretch focus on the rectus abdominis, your obliques and your psoas major and minor. Pulling your stomach muscules taught evenly across your mid section is important because we don't realise that when when we walk or run we are rotating our hips but we dont rotate our shoulders and hence we flex our stomach muscles. But they never get stretched.
These stretches are fairly easy to do and they will increase you flexibility which is a requirement just to do simple exercise. Whilst doing the rotating stomach stretch you should feel the pull from you pelvic region, or your iliacus, up to the top of the external oblique with an even pressure on the side your facing away from. During the rising stomach stretch you should feel the same sort of pull just along both side of your stomach.
Don't ever under estimate the importance of stretching and the benefits it holds.
The Rotation Stomach stretch is useful for abdominal strain, hip flexor strain and Iliopsoas tendonitis.
The Rising Stomach stretch is used for the same issues.
Always remember that while stretching may be recommended to aid recovery out of injury, you should always be very careful when stretching through rehabilitation. Your soft tissues are likely to be more vulnerable to re-injury if you stretch too much or too hard during this time. Always check with your Health Care Professional who is guiding you through your recovery to make sure it is appropriate to start stretching, and please - ALWAYS FOLLOW THE RULES FOR SAFE STRETCHING (The first posting on this stretching blog).
Image taken from "Lower Body Stretches" wall chart by B. Walker.