Props are very useful to improve your flexibility. and strength. In this Picture you can see ustrasana or camelpose with swissball. How to do? 1. First make sure that swiss ball is comfortable for you. 2. Put your lower back on swiss ball very gently. 3. Make sure we have not to seat on Swiss ball. 4. slowly drop your self and neck towards to the floor.. 5. If you are not comfortable with it, then do it under any instructor. Benefits :- 1. It is good to improve your lower back strength 2. Its good for improving your spine strength.