If you feel that you back is ready,strong and flexible enough you can move on to getting your foot to your head. Start out in the same pose as the one that was used in the mermaid pose. Reach back and draw your heel in towards your hip, hold this position for a few breaths. This will start to give you nice length in your quadriceps. Now reach back and take your thumb and forefinger around your foot and pull your elbow forward. Now start to bring your foot to your head. If you need help with this exercise you can use a strap or a belt latched to your foot and then use the strap to bring your foot to your head. You can even start to walk your hands down the strap which will increase the difficulty. Remember to keep your belly drawn in while you perform these poses.