These are more advanced exercises for strengthening your lower back.
Here is an example of more advanced back strengthening.
Disclaimer: The exercises provided on this website are for educational and entertainment purposes only, and are not to be interpreted as a recommendation for a specific treatment plan, product, or course of action. Exercise is not without its risks, and this or any other exercise program may result in injury. To reduce the risk of injury, before beginning this or any exercise program, please consult a healthcare provider for appropriate exercise prescription and safety precautions.