One thing that is often forgotten is that your core, is not just about the front of your body. The core has three parts your front, sides, and back. Everyone is aware of the exercises for your abs, how about the other two?
A great way to strengthen your back is to do back extensions; they are easy to do and easy to modify if necessary.
If you need to modify the move; you can do this by leaving your hands on the mat and using them for support.
For the sides of your body, an excellent exercise is the side-plank. Which you can make more difficult by rotating with your free arm in the side-plank position.
